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University of Bristol
1.
Logan, Crispin H. A.
Galaxy cluster science with Chandra.
Degree: PhD, 2020, University of Bristol
URL: http://hdl.handle.net/1983/10568231-6d41-4aba-a914-6ef9ca4e3308 
► Galaxy clusters are the largest gravitationally bound structures in our Universe, and hence can be used to constrain the physical laws that govern cosmic evolution.…
(more)
▼ Galaxy clusters are the largest gravitationally bound structures in our Universe, and hence can be used to constrain the physical laws that govern cosmic evolution. In order to use clusters as cosmological probes, large samples of bona-fide clusters are needed, in addition to a method with which to estimate cluster masses accurately. Additionally, clusters can be studied to understand the physical processes within the clusters themselves. As clusters form via hierarchical growth, growing ever larger through mergers with smaller systems and accretion of matter from the surrounding environment, understanding the physical processes in the outer regions of a cluster can tell us more about how they grow. The first project in my PhD tackled the issue of constructing reliable samples of clusters for cosmology, specifically analysing Chandra observations of high redshift cluster candidates detected in the XXL survey, to probe not only their AGN contamination, but also to ensure that they were indeed genuine clusters. The second project in my PhD focussed on the calibration of the X-ray hydrostatic cluster mass estimation method, by comparing the X-ray hydrostatic masses of a sample of 44 clusters with masses for the same sample of clusters measured with an entirely independent method based on information on galaxy dynamics obtained from optical observations. The final project in my PhD used the same sample of clusters as the mass calibration work to study the outer regions of clusters, specifically calculating the gas fraction at large radii of these clusters, to gain insight into the state of the cluster gas in the cluster outskirts.
Subjects/Keywords: galaxy clusters
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APA (6th Edition):
Logan, C. H. A. (2020). Galaxy cluster science with Chandra. (Doctoral Dissertation). University of Bristol. Retrieved from http://hdl.handle.net/1983/10568231-6d41-4aba-a914-6ef9ca4e3308
Chicago Manual of Style (16th Edition):
Logan, Crispin H A. “Galaxy cluster science with Chandra.” 2020. Doctoral Dissertation, University of Bristol. Accessed January 22, 2021.
http://hdl.handle.net/1983/10568231-6d41-4aba-a914-6ef9ca4e3308.
MLA Handbook (7th Edition):
Logan, Crispin H A. “Galaxy cluster science with Chandra.” 2020. Web. 22 Jan 2021.
Vancouver:
Logan CHA. Galaxy cluster science with Chandra. [Internet] [Doctoral dissertation]. University of Bristol; 2020. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/1983/10568231-6d41-4aba-a914-6ef9ca4e3308.
Council of Science Editors:
Logan CHA. Galaxy cluster science with Chandra. [Doctoral Dissertation]. University of Bristol; 2020. Available from: http://hdl.handle.net/1983/10568231-6d41-4aba-a914-6ef9ca4e3308
University of Bristol
2.
Logan, Crispin H. A.
Galaxy cluster science with Chandra.
Degree: PhD, 2020, University of Bristol
URL: https://research-information.bris.ac.uk/en/studentTheses/10568231-6d41-4aba-a914-6ef9ca4e3308
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805629
► Galaxy clusters are the largest gravitationally bound structures in our Universe, and hence can be used to constrain the physical laws that govern cosmic evolution.…
(more)
▼ Galaxy clusters are the largest gravitationally bound structures in our Universe, and hence can be used to constrain the physical laws that govern cosmic evolution. In order to use clusters as cosmological probes, large samples of bona-fide clusters are needed, in addition to a method with which to estimate cluster masses accurately. Additionally, clusters can be studied to understand the physical processes within the clusters themselves. As clusters form via hierarchical growth, growing ever larger through mergers with smaller systems and accretion of matter from the surrounding environment, understanding the physical processes in the outer regions of a cluster can tell us more about how they grow. The first project in my PhD tackled the issue of constructing reliable samples of clusters for cosmology, specifically analysing Chandra observations of high redshift cluster candidates detected in the XXL survey, to probe not only their AGN contamination, but also to ensure that they were indeed genuine clusters. The second project in my PhD focussed on the calibration of the X-ray hydrostatic cluster mass estimation method, by comparing the X-ray hydrostatic masses of a sample of 44 clusters with masses for the same sample of clusters measured with an entirely independent method based on information on galaxy dynamics obtained from optical observations. The final project in my PhD used the same sample of clusters as the mass calibration work to study the outer regions of clusters, specifically calculating the gas fraction at large radii of these clusters, to gain insight into the state of the cluster gas in the cluster outskirts.
Subjects/Keywords: galaxy clusters
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Logan, C. H. A. (2020). Galaxy cluster science with Chandra. (Doctoral Dissertation). University of Bristol. Retrieved from https://research-information.bris.ac.uk/en/studentTheses/10568231-6d41-4aba-a914-6ef9ca4e3308 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805629
Chicago Manual of Style (16th Edition):
Logan, Crispin H A. “Galaxy cluster science with Chandra.” 2020. Doctoral Dissertation, University of Bristol. Accessed January 22, 2021.
https://research-information.bris.ac.uk/en/studentTheses/10568231-6d41-4aba-a914-6ef9ca4e3308 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805629.
MLA Handbook (7th Edition):
Logan, Crispin H A. “Galaxy cluster science with Chandra.” 2020. Web. 22 Jan 2021.
Vancouver:
Logan CHA. Galaxy cluster science with Chandra. [Internet] [Doctoral dissertation]. University of Bristol; 2020. [cited 2021 Jan 22].
Available from: https://research-information.bris.ac.uk/en/studentTheses/10568231-6d41-4aba-a914-6ef9ca4e3308 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805629.
Council of Science Editors:
Logan CHA. Galaxy cluster science with Chandra. [Doctoral Dissertation]. University of Bristol; 2020. Available from: https://research-information.bris.ac.uk/en/studentTheses/10568231-6d41-4aba-a914-6ef9ca4e3308 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805629
University of Waterloo
3.
Vantyghem, Adrian.
An ALMA View of Molecular Gas in Brightest Cluster Galaxies.
Degree: 2018, University of Waterloo
URL: http://hdl.handle.net/10012/13915
► In this thesis I use ALMA observations to map the distribution and kinematics of molecular gas in the brightest cluster galaxies of three galaxy clusters:…
(more)
▼ In this thesis I use ALMA observations to map the distribution and kinematics of molecular gas in the brightest cluster galaxies of three galaxy clusters: 2A0335+096, RXJ0821+0752, and RXCJ1504-0248. The goal is to understand how the coldest gas in clusters is formed, identify any long-lived structures that could fuel sustained black hole accretion, and explore star formation in cluster environments. I use the J=1-0 and J=3-2 rotational transitions of carbon monoxide (CO) as tracers of the total molecular gas distribution. The two transitions provide different resolutions and fields of view.
The molecular gas in all three central galaxies are complex and disturbed. None show evidence for rotationally-supported nuclear structures, such as a disk or ring, that would be expected from either a merger origin or long-lived cooling flow. Instead, the molecular gas is either clumpy with no clear velocity structure or extends away from the galactic center in filaments that are several kiloparsecs long. The molecular filaments are coincident with nebular and bright X-ray emission, suggesting that they have condensed out of the hot intracluster medium. They are also generally associated with cavities in the X-ray emission inflated by the active galactic nucleus (AGN), suggesting that AGN feedback has stimulated the formation of molecular gas. The narrow velocity gradients along the filaments are only consistent with freefall if the filament is situated close to the plane of the sky. This is a common feature in brightest cluster galaxies. Since ram pressure is ineffective at slowing dense molecular clouds, the filaments must either be pinned to the hot atmosphere by magnetic fields or have condensed in-situ relatively recently.
In RXCJ1504-0248 I combine the ALMA analysis with spatially-resolved ultraviolet emission tracing young stars. The central gas falls on the Kennicutt-Schmidt relation, while the filament has elevated star formation surface densities. The ongoing consumption of a finite fuel supply by star formation, or spatial variations in the CO-to-H2 conversion factor, may be diminishing the molecular gas surface density to produce this effect. Despite their drastic differences in morphology and environment, the molecular gas in clusters is still converted into stars following the same relation as in spirals and starbursts.
I have also detected the J=3-2 transition from 13CO, an optically thin isotopologue of 12CO, in RXJ0821.0+0752. This enables a measurement of the conversion between CO intensity and molecular column density for the first time in a galaxy cluster. The CO-to-H2 conversion factor in RXJ0821+0752 is half of the Galactic value. If this value applies to other clusters, then it would alleviate the high coupling efficiencies required for molecular filaments to be uplifted by X-ray cavities. This analysis also provides reassurance that the molecular gas masses measured in BCGs are unlikely to be overwhelmingly biased by adopting the Galactic conversion factor.
Subjects/Keywords: Galaxies; Galaxy Clusters
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APA (6th Edition):
Vantyghem, A. (2018). An ALMA View of Molecular Gas in Brightest Cluster Galaxies. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/13915
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Vantyghem, Adrian. “An ALMA View of Molecular Gas in Brightest Cluster Galaxies.” 2018. Thesis, University of Waterloo. Accessed January 22, 2021.
http://hdl.handle.net/10012/13915.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Vantyghem, Adrian. “An ALMA View of Molecular Gas in Brightest Cluster Galaxies.” 2018. Web. 22 Jan 2021.
Vancouver:
Vantyghem A. An ALMA View of Molecular Gas in Brightest Cluster Galaxies. [Internet] [Thesis]. University of Waterloo; 2018. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10012/13915.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Vantyghem A. An ALMA View of Molecular Gas in Brightest Cluster Galaxies. [Thesis]. University of Waterloo; 2018. Available from: http://hdl.handle.net/10012/13915
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
4.
Hodson, Alistair.
A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
.
Degree: 2017, University of St. Andrews
URL: http://hdl.handle.net/10023/12016
► This thesis attempts to test several frameworks of non-Newtonian gravity in the context of galaxies and galaxy clusters. The theory most extensively discussed was that…
(more)
▼ This thesis attempts to test several frameworks of non-Newtonian gravity in the context of galaxies and
galaxy clusters. The theory most extensively discussed was that of Modified Newtonian Dynamics (MOND) with Galileon gravity, Emergent Gravity (EG) and Modified Gravity (MOG) mentioned to a lesser extent. Specifically, the main focus of this thesis was to determine whether MOND and MOND-like theories were compatible with
galaxy cluster data, without the need to include cold dark matter. To do this, the paradigms of Extended MOND (EMOND), Generalised MOND (GMOND) and superfluid dark matter were investigated. The theories were outlined and applied to
galaxy cluster data. The main findings of this were that EMOND and GMOND had some success with explaining
galaxy cluster mass profiles, without requiring an additional dark matter component. The superfluid paradigm also enjoyed some success in
galaxy clusters, which was expected as it behaves in a similar manner to the standard cold dark matter paradigm in cluster environments. However, the superfluid paradigm may have issues in the very centre of
galaxy clusters due to the theory predicting constant density cores, whereas the cold dark matter paradigm predicts density cores which are cuspier.
The EMOND paradigm was also tested against ultra-diffuse
galaxy (UDGs) data as they appear in cluster environments, where EMOND becomes important. It was found that EMOND can reproduce the inferred mass of the UDGs, assuming they lie on the fundamental manifold (FM). The validity of the assumptions used to model the UDGs are discussed in the text.
A two-body problem was also conducted in the Galileon gravity framework. The amount of additional gravitational force, compared to Newtonian was determined for a small
galaxy at the edge of a
galaxy cluster.
Advisors/Committee Members: Zhao, Hongsheng (advisor).
Subjects/Keywords: Galaxy dynamics;
Modified gravity;
Galaxy clusters
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APA ·
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Manager
APA (6th Edition):
Hodson, A. (2017). A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
. (Thesis). University of St. Andrews. Retrieved from http://hdl.handle.net/10023/12016
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Hodson, Alistair. “A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
.” 2017. Thesis, University of St. Andrews. Accessed January 22, 2021.
http://hdl.handle.net/10023/12016.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Hodson, Alistair. “A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
.” 2017. Web. 22 Jan 2021.
Vancouver:
Hodson A. A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
. [Internet] [Thesis]. University of St. Andrews; 2017. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10023/12016.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Hodson A. A non-Newtonian perspective of gravity : testing modified gravity theories in galaxies and galaxy clusters
. [Thesis]. University of St. Andrews; 2017. Available from: http://hdl.handle.net/10023/12016
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Manchester
5.
Pearce, Francesca.
Simulations of galaxy clusters.
Degree: 2020, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:325093
► Galaxy clusters are the largest virialised objects in the present-day Universe. Clusters are complex systems which can be used as a cosmological probe as they…
(more)
▼ Galaxy clusters are the largest virialised objects
in the present-day Universe.
Clusters are complex systems which can
be used as a cosmological probe as they trace the large-scale mass
distribution, but they also incorporate non-gravitational processes
which make them excellent tests of
galaxy formation and evolution.
Due to the extremely complex nature of
galaxy clusters, numerical
simulations are increasingly important in order to test and
understand all the different astrophysical processes that are
involved in galaxies and
galaxy clusters, which can be informed by
and compared to observations. In this thesis, we have used the low
resolution CELR sample to produce more evidence for a mass
dependence of the hydrostatic mass biass, which increases from
around 20 per cent to 40 per cent in the most massive objects. It
is important to understand and characterise this bias in order to
use
clusters for cosmology. We have also looked at the metallicity
distribution of the C-EAGLE
clusters and found that, in general,
the cluster outskirts are compatible with the early enrichment
model. The C-EAGLE
clusters show considerable evolution in the core
as a result of accretion of low metallicity gas, suggesting that
active galactic nuclei have a bigger impact on metals in cluster
cores than has previously been seen. Finally, we have designed and
tested a module to reduce the distribution of gas particle masses
in cosmological simulations to preserve the underlying smoothed
particle hydrodynamics which assume a constant particle mass. This
module was successfully implemented in the EAGLE cosmological code,
but was unable to stop the formation of entropy cores in
clusters.
Advisors/Committee Members: JACKSON, NEAL NJF, Kay, Scott, Jackson, Neal.
Subjects/Keywords: Galaxy clusters; Simulations; Cosmology
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APA ·
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Manager
APA (6th Edition):
Pearce, F. (2020). Simulations of galaxy clusters. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:325093
Chicago Manual of Style (16th Edition):
Pearce, Francesca. “Simulations of galaxy clusters.” 2020. Doctoral Dissertation, University of Manchester. Accessed January 22, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:325093.
MLA Handbook (7th Edition):
Pearce, Francesca. “Simulations of galaxy clusters.” 2020. Web. 22 Jan 2021.
Vancouver:
Pearce F. Simulations of galaxy clusters. [Internet] [Doctoral dissertation]. University of Manchester; 2020. [cited 2021 Jan 22].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:325093.
Council of Science Editors:
Pearce F. Simulations of galaxy clusters. [Doctoral Dissertation]. University of Manchester; 2020. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:325093
University of Manchester
6.
Cantwell, Therese Mairead.
LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS.
Degree: 2018, University of Manchester
URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:313848
► The detection of Mpc scale diffuse radio emission in galaxy clusters provides evidence that cosmic ray electrons, as well as cluster scale magnetic fields are…
(more)
▼ The detection of Mpc scale diffuse radio emission
in
galaxy clusters provides evidence that cosmic ray electrons, as
well as cluster scale magnetic fields are present in
clusters. As
such, radio observations of
clusters provide a unique opportunity
to study the non-thermal populations of the intra-cluster medium.
Observations of Faraday rotation in sources embedded in cluster and
group environments offers an additional method for probing the
cluster/group magnetic field. In this thesis I present low
frequency radio observations of multiple
galaxy clusters in order
to investigate the nature of diffuse radio emission present in many
clusters. I also present observations of the giant radio
galaxy NGC
6251 and discuss both the source properties as well as the host
group environment. In Chapter 1 of this thesis I review the current
understanding of
galaxy clusters, groups and radio galaxies. I also
describe some of the astrophysical processes important to this
thesis. In Chapter 2 I discuss the interferometry and the process
of calibrating interferometric data. I also describe some of the
techniques used later in the thesis such as QUfitting and RM
synthesis. In Chapter 3 I present my observations of the massive
merging
galaxy cluster MACSJ2243.3-0935. I report the discovery of
a radio halo in MACSJ2243.3-0935, as well as a new radio relic
candidate, using the Giant Meterwave Radio Telescope and the KAT-7
telescope. The radio halo is coincident with the cluster X-ray
emission and has a largest linear scale of approximately 0.9 Mpc. I
measure a flux density of 10.0± 2.0\, mJy at 610 MHz for
the radio halo. I discuss equipartition estimates of the cluster
magnetic field and constrain the value to be of the order of 1\,
μ G. The relic candidate is detected at the cluster virial
radius where a filament meets the cluster. The relic candidate has
a flux density of 5.2± 0.8\, mJy at 610 MHz. I discuss
possible origins of the relic candidate emission and conclude that
the candidate is consistent with an infall relic. In Chapter 4 I
present my GMRT observations at 610 MHz of 3 disturbed
galaxy
clusters, A07, A1235 and A2055. No diffuse emision was observed any
of the three
clusters. In order to place upper limits on the radio
halo power in these
clusters I have injected simulated halos at
difffent radio powers into the uvdata. A07 has a radio halo upper
limit of P
610MHz=1.5 × 10
24 W Hz
-1. A2055 has a
radio halo upper limit of P
610MHz=1.8 × 10
24 W
Hz
-1. A1235 has a radio halo upper limit of P
610MHz=5.8 × 10
23 W Hz
-1. These limits are below the
P
610-L
X relation and rule out bright radio halo in
these
clusters. I have identified these
clusters as potential hosts
for Ultra Steep Spectrum Radio Halo (USSRH). Observations with
LOFAR should be capable of confirming whether or not these
clusters
host USSRH. In Chapter 5 I present observations of the giant radio
galaxy NGC 6251 with LOFAR HBA. NGC 6251 is a giant radio
galaxy
with a borderline…
Advisors/Committee Members: GRAINGE, KEITH K, Scaife, Anna, Grainge, Keith.
Subjects/Keywords: Galaxy Clusters; Radio Galaxies
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APA ·
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MLA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Cantwell, T. M. (2018). LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:313848
Chicago Manual of Style (16th Edition):
Cantwell, Therese Mairead. “LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS.” 2018. Doctoral Dissertation, University of Manchester. Accessed January 22, 2021.
http://www.manchester.ac.uk/escholar/uk-ac-man-scw:313848.
MLA Handbook (7th Edition):
Cantwell, Therese Mairead. “LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS.” 2018. Web. 22 Jan 2021.
Vancouver:
Cantwell TM. LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS. [Internet] [Doctoral dissertation]. University of Manchester; 2018. [cited 2021 Jan 22].
Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:313848.
Council of Science Editors:
Cantwell TM. LOW FREQUENCY RADIO OBSERVATIONS OF GALAXY CLUSTERS AND
GROUPS. [Doctoral Dissertation]. University of Manchester; 2018. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:313848
7.
McCleary, Jacqueline Elizabeth.
Dark Matter Substructure in Very Low Redshift Galaxy
Clusters.
Degree: Department of Physics, 2017, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:792597/
► This work sets forth the methods and first results of our study of ∼ 1E14 M⊙ mass substructures in very low redshift (z < 0.12)…
(more)
▼ This work sets forth the methods and first results of
our study of ∼ 1E14 M⊙ mass substructures in very low redshift (z
< 0.12)
galaxy clusters. We have begun by performing a detailed
2-dimensional weak gravitational lensing analysis of five nearby
clusters using deep ugriz imaging from the Dark Energy Camera
(DECam) at the Cerro Tololo Inter-American Observatory. In our
pilot study on Abell 3128, we designed a pipeline to remove
instrumental artifacts from DECam images and stack multiple
dithered observations without inducing a spurious ellipticity
signal. We developed a new technique to characterize the spatial
variation of the point spread function and so extract the intrinsic
galaxy ellipticities. In both A3128 and ensuing studies, we
detected multiple high-significance substructures within the
clusters. By fitting photometric redshifts to sources in the
cluster observations, we selected a sample of back- ground galaxies
for weak lensing analysis free from foreground contaminants.
Photometric redshifts were also used to select high-redshift
galaxy
subsamples with which we successfully isolated the signal from
several interloping background
clusters. We estimate the mass of
clusters in this work by fitting the tangential ellipticity of
background galaxies with the weak lensing shear profile of an NFW
halo, and also perform NFW fits to substructures detected in the
weak lensing maps. Upper mass limits for several high-redshift
clusters are also reported. This work yields some of the highest
resolution mass maps of low-z
clusters to date, and is the first
step in a larger effort to characterize the redshift evolution of
substructures in
clusters. We conclude with future directions for
our research, including continuing our study of substructure in
more low-redshift
clusters and build a substructure mass
function.
Advisors/Committee Members: dell'Antonio, Ian (Advisor), Koushiappas, Savvas (Reader), Gaitskell, Richard (Reader).
Subjects/Keywords: Physics; Astrophysics; Galaxy Clusters;
Cosmology
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APA ·
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Manager
APA (6th Edition):
McCleary, J. E. (2017). Dark Matter Substructure in Very Low Redshift Galaxy
Clusters. (Thesis). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:792597/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
McCleary, Jacqueline Elizabeth. “Dark Matter Substructure in Very Low Redshift Galaxy
Clusters.” 2017. Thesis, Brown University. Accessed January 22, 2021.
https://repository.library.brown.edu/studio/item/bdr:792597/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
McCleary, Jacqueline Elizabeth. “Dark Matter Substructure in Very Low Redshift Galaxy
Clusters.” 2017. Web. 22 Jan 2021.
Vancouver:
McCleary JE. Dark Matter Substructure in Very Low Redshift Galaxy
Clusters. [Internet] [Thesis]. Brown University; 2017. [cited 2021 Jan 22].
Available from: https://repository.library.brown.edu/studio/item/bdr:792597/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
McCleary JE. Dark Matter Substructure in Very Low Redshift Galaxy
Clusters. [Thesis]. Brown University; 2017. Available from: https://repository.library.brown.edu/studio/item/bdr:792597/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Universidad de Cantabria
8.
Herranz Muñoz, Diego.
Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters.
Degree: 2006, Universidad de Cantabria
URL: http://hdl.handle.net/10902/1575
► RESUMEN: El estudio de las anisotropías de la Radiación Cósmica del Fondo de Microondas es una de las piedras de toque de la Cosmología actual.…
(more)
▼ RESUMEN: El estudio de las anisotropías de la Radiación Cósmica del Fondo de Microondas es una de las piedras de toque de la Cosmología actual. Una fase importante de dicho estudio consiste en el análisis previo de los datos mediante técnicas de
procesado estadístico que permiten identificar, separar y estudiar de forma independiente las diferentes componentes físicas que contribuyen a la emisión del cielo. En esta Tesis se propone una nueva técnica de filtrado, los Filtros Adaptados a la Escala, que permite detectar la emisión de fuentes compactas(galaxias y cúmulos de galaxias) de forma robusta atendiendo a
las particularidades de su estructura espacial a pequeña escala.
Los Filtros Adaptados a la Escala se introducen de forma teórica y posteriormente son aplicados a simulaciones realistas que reproducen las condiciones de la futura misión de la Agencia
Espacial Europea "Planck", tanto en el régimen unidimensional como en imágenes bidimensionales en una o varias frecuencias (según se trate de detección de galaxias o de cúmulos de galaxias). Se concluye que los Filtros Adaptados a la Escala
constituyen una herramienta potente y robusta para la detección de fuentes compactas en imágenes astronómicas.
Advisors/Committee Members: Sanz Estévez, José Luis (advisor), Universidad de Cantabria (other).
Subjects/Keywords: Galaxy clusters
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APA (6th Edition):
Herranz Muñoz, D. (2006). Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters. (Doctoral Dissertation). Universidad de Cantabria. Retrieved from http://hdl.handle.net/10902/1575
Chicago Manual of Style (16th Edition):
Herranz Muñoz, Diego. “Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters.” 2006. Doctoral Dissertation, Universidad de Cantabria. Accessed January 22, 2021.
http://hdl.handle.net/10902/1575.
MLA Handbook (7th Edition):
Herranz Muñoz, Diego. “Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters.” 2006. Web. 22 Jan 2021.
Vancouver:
Herranz Muñoz D. Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters. [Internet] [Doctoral dissertation]. Universidad de Cantabria; 2006. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10902/1575.
Council of Science Editors:
Herranz Muñoz D. Análisis de las anisotropías de la radiación cósmica del fondo de microondas mediante el uso de filtros adaptados: Analysis of the anisotropies in the cosmic microwave background radiation using adaptive filters. [Doctoral Dissertation]. Universidad de Cantabria; 2006. Available from: http://hdl.handle.net/10902/1575
University of Manchester
9.
Pearce, Francesca.
Simulations of galaxy clusters.
Degree: PhD, 2020, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-galaxy-clusters(41571ff8-5c79-425c-9742-8f56d535d16a).html
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809447
► Galaxy clusters are the largest virialised objects in the present-day Universe. Clusters are complex systems which can be used as a cosmological probe as they…
(more)
▼ Galaxy clusters are the largest virialised objects in the present-day Universe. Clusters are complex systems which can be used as a cosmological probe as they trace the large-scale mass distribution, but they also incorporate non-gravitational processes which make them excellent tests of galaxy formation and evolution. Due to the extremely complex nature of galaxy clusters, numerical simulations are increasingly important in order to test and understand all the different astrophysical processes that are involved in galaxies and galaxy clusters, which can be informed by and compared to observations. In this thesis, we have used the low resolution CELR sample to produce more evidence for a mass dependence of the hydrostatic mass biass, which increases from around 20 per cent to 40 per cent in the most massive objects. It is important to understand and characterise this bias in order to use clusters for cosmology. We have also looked at the metallicity distribution of the C-EAGLE clusters and found that, in general, the cluster outskirts are compatible with the early enrichment model. The C-EAGLE clusters show considerable evolution in the core as a result of accretion of low metallicity gas, suggesting that active galactic nuclei have a bigger impact on metals in cluster cores than has previously been seen. Finally, we have designed and tested a module to reduce the distribution of gas particle masses in cosmological simulations to preserve the underlying smoothed particle hydrodynamics which assume a constant particle mass. This module was successfully implemented in the EAGLE cosmological code, but was unable to stop the formation of entropy cores in clusters.
Subjects/Keywords: Galaxy clusters; Simulations; Cosmology
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APA (6th Edition):
Pearce, F. (2020). Simulations of galaxy clusters. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-galaxy-clusters(41571ff8-5c79-425c-9742-8f56d535d16a).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809447
Chicago Manual of Style (16th Edition):
Pearce, Francesca. “Simulations of galaxy clusters.” 2020. Doctoral Dissertation, University of Manchester. Accessed January 22, 2021.
https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-galaxy-clusters(41571ff8-5c79-425c-9742-8f56d535d16a).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809447.
MLA Handbook (7th Edition):
Pearce, Francesca. “Simulations of galaxy clusters.” 2020. Web. 22 Jan 2021.
Vancouver:
Pearce F. Simulations of galaxy clusters. [Internet] [Doctoral dissertation]. University of Manchester; 2020. [cited 2021 Jan 22].
Available from: https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-galaxy-clusters(41571ff8-5c79-425c-9742-8f56d535d16a).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809447.
Council of Science Editors:
Pearce F. Simulations of galaxy clusters. [Doctoral Dissertation]. University of Manchester; 2020. Available from: https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-galaxy-clusters(41571ff8-5c79-425c-9742-8f56d535d16a).html ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809447
University of Waterloo
10.
Mehmood, Harisah.
Galaxy Morphology In Cluster Environments.
Degree: 2017, University of Waterloo
URL: http://hdl.handle.net/10012/12226
► It is a well known fact that cluster environments favour early-type galaxies over late- type. However, the physical origin of the correlation remains uncertain. We…
(more)
▼ It is a well known fact that cluster environments favour early-type galaxies over late- type. However, the physical origin of the correlation remains uncertain. We focus specifically on the external environmental mechanisms responsible for morphologi- cal transformation of late-type into early-type galaxies using ∼ 30,000 satellites in 625 clusters from SDSS DR7. All the external processes have one factor in common which is the orbital path taken by a satellite through the cluster that determines the extent of the environmental effects. We use results from orbital libraries extracted from N-body simulations. These give a probabilistic mapping between normalized projected phase-space (R, V ) coordinates to lookback time to cluster infall. The look back time is the key ingredient that traces how far the satellite is in its orbit compared to the cluster centre. Using these results, we explore the effects of a de- crease in disc luminosity caused by disc quenching and disc scale length reduction on satellite morphology quantified by the luminous bulge-to-total (B/T) ratio. Our findings suggest that satellites are quenched and their disc scale lengths are reduced after spending ∼ 5 Gyrs in the cluster which corresponds to ∼ 1 Gyr after pass- ing the pericenter. A drop in disc luminosity due to these processes has a small impact on morphology suggesting that other active processes such as harassment are responsible for further morphological transformations. Fitting to account for such processes over and above the ones responsible for a drop in disc luminosity, we find that satellites with B/T < 0.1 (pure disc systems) experience most drastic changes: their structure changes by developing a bulge component ∼ 5 Gyrs after infall. Similarly, objects with 0.1 < B/T < 0.3, are affected by harassment over a longer time scale ∼ 7 Gyrs suggesting that satellites with a bulge component are more resistant to harassment compared to pure disc systems. We conclude that the density-morphology relationship is a manifestation of both hydrodynamical as well as gravitational processes driving late-type to early-type morphology.
Subjects/Keywords: galaxies; galaxy morphology; clusters; quenching
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APA (6th Edition):
Mehmood, H. (2017). Galaxy Morphology In Cluster Environments. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/12226
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mehmood, Harisah. “Galaxy Morphology In Cluster Environments.” 2017. Thesis, University of Waterloo. Accessed January 22, 2021.
http://hdl.handle.net/10012/12226.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mehmood, Harisah. “Galaxy Morphology In Cluster Environments.” 2017. Web. 22 Jan 2021.
Vancouver:
Mehmood H. Galaxy Morphology In Cluster Environments. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10012/12226.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mehmood H. Galaxy Morphology In Cluster Environments. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/12226
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
11.
Sultanova, Madina Renatovna.
Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters.
Degree: PhD, Physics & Astrophysics, 2018, University of North Dakota
URL: https://commons.und.edu/theses/2358
► The classification of galaxies based on their morphology (i.e. structural properties) is a field in astrophysics that aims to understand galaxy formation and evolution…
(more)
▼ The classification of galaxies based on their morphology (i.e. structural properties) is a field in astrophysics that aims to understand
galaxy formation and evolution based on their physical differences. Whether structural differences are due to internal factors or a result of local environment, the dominate mechanism that determines
galaxy type needs to be robustly quantified in order to have a thorough grasp of the origin of the different types of galaxies (e.g., elliptical, S0, spiral, and irregular). The main
subject of this thesis is to explore the use of computers to automatically analyze and classify large numbers of galaxies based on their morphology, and to analyze sub-samples of galaxies selected by type to understand
galaxy formation and evolution in various environments. I have developed computer software to classify galaxies by measuring specific parameters extracted from digital images. In particular, I have constructed computer algorithms to calculate five classification parameters for a list of galaxies in a single FITS image. This research has important implications for increasing our knowledge of
galaxy formation and evolution in dense systems. A diverse range of data sets is studied, primarily focusing on: Rude (2015), Barkhouse et al. (2007), WINGS (Fasano et al. 2006), and Baillard et al. (2011). The data sets include galaxies from a wide range of redshifts, from 0.03 ⤠z ⤠0.20. The different span of redshift allows for comparison of distant
clusters with those nearby in order to look for evolutionary changes in the
galaxy cluster population.
Advisors/Committee Members: Wayne Barkhouse.
Subjects/Keywords: classification; galaxy classification; galaxy clusters; galaxy morphology; morphology; software
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Manager
APA (6th Edition):
Sultanova, M. R. (2018). Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters. (Doctoral Dissertation). University of North Dakota. Retrieved from https://commons.und.edu/theses/2358
Chicago Manual of Style (16th Edition):
Sultanova, Madina Renatovna. “Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters.” 2018. Doctoral Dissertation, University of North Dakota. Accessed January 22, 2021.
https://commons.und.edu/theses/2358.
MLA Handbook (7th Edition):
Sultanova, Madina Renatovna. “Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters.” 2018. Web. 22 Jan 2021.
Vancouver:
Sultanova MR. Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters. [Internet] [Doctoral dissertation]. University of North Dakota; 2018. [cited 2021 Jan 22].
Available from: https://commons.und.edu/theses/2358.
Council of Science Editors:
Sultanova MR. Automatic Approach To Morphological Classification Of Galaxies With Analysis Of Galaxy Populations In Clusters. [Doctoral Dissertation]. University of North Dakota; 2018. Available from: https://commons.und.edu/theses/2358
University of Michigan
12.
Gifford, Daniel William.
Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters.
Degree: PhD, Astronomy and Astrophysics, 2016, University of Michigan
URL: http://hdl.handle.net/2027.42/120771
► Galaxy clusters are large virialized structures that exist at the intersection of filaments of matter that make up the cosmic web. Due to their hierarchical…
(more)
▼ Galaxy clusters are large virialized structures that exist at the intersection of filaments of matter that make up the cosmic web. Due to their hierarchical growth history, they are excellent probes of the cosmology that governs our universe. Here, we aim to use
clusters to better constrain cosmological parameters by systematically studying the uncertainties on
galaxy cluster mass estimation for use in a halo mass function analysis. We find that the caustic technique is capable on average of recovering unbiased cluster masses to within 30% for well sampled systems. We also quantify potential statistical and systematic biases due to observational challenges. To address statistical biases in the caustic technique, we developed a new stacking algorithm to measure the average cluster mass for a single stack of projected cluster phase-spaces. By varying the number of galaxies and number of
clusters we stack, we find that the single limited value is the total number of galaxies in the stack opening up the possibility for self-calibrated mass estimates of low mass or poorly sampled
clusters in large surveys. We then utilize the SDSS-C4 catalog of
galaxy clusters to place some of the tightest
galaxy cluster based constraints on the matter density and power spectrum normalization for matter in our universe.
Advisors/Committee Members: Miller, Christopher John (committee member), Evrard, August (committee member), Gnedin, Oleg (committee member), Sharon, Keren (committee member).
Subjects/Keywords: Cosmology; Galaxy Clusters; Extragalactic; Astronomy; Science
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APA (6th Edition):
Gifford, D. W. (2016). Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/120771
Chicago Manual of Style (16th Edition):
Gifford, Daniel William. “Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters.” 2016. Doctoral Dissertation, University of Michigan. Accessed January 22, 2021.
http://hdl.handle.net/2027.42/120771.
MLA Handbook (7th Edition):
Gifford, Daniel William. “Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters.” 2016. Web. 22 Jan 2021.
Vancouver:
Gifford DW. Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/2027.42/120771.
Council of Science Editors:
Gifford DW. Estimating Cosmological Parameters and Cluster Masses through Escape Velocity Measurements in Galaxy Clusters. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/120771
University of Michigan
13.
Johnson, Traci.
Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing.
Degree: PhD, Astronomy and Astrophysics, 2018, University of Michigan
URL: http://hdl.handle.net/2027.42/144156
► Massive galaxy clusters are capable of magnifying background sources and thus act as natural telescopes to the distant Universe. My dissertation focuses on modeling the…
(more)
▼ Massive
galaxy clusters are capable of magnifying background sources and thus act as natural telescopes to the distant Universe. My dissertation focuses on modeling the mass distributions of these
clusters in order to determine to what degree intrinsic properties of background sources such as luminosity, star formation rate, and size have been magnified. With accurate and precise lens models, we can compute the luminosity functions of the most distant galaxies at z > 8, pushing beyond the limits of HST deep fields, which will help to understand the formation of galaxies during the epoch of re-ionization. We can also use cluster lensing to zoom into galaxies at z ~ 2 to study their star formation morphologies on scales smaller than a kiloparsec, science that will not be feasible for field galaxies until JWST comes online. In addition to creating lens models, my dissertation also looks at the systematic errors associated with lens modeling techniques. As I will show, lens model accuracy can depend on the number of constraints as well as the availability of spectroscopic redshifts used in the modeling process. Understanding the systematic errors of lens models will be necessary in the next decade, when several wide-field surveys will reveal thousands of new strong lensing systems, for which higher resolution imaging and spectroscopic data may not be obtained for all systems.
Advisors/Committee Members: Sharon, Keren (committee member), Evrard, August (committee member), Kneib, Jean-Paul (committee member), Miller, Christopher John (committee member), Miller, Jon Matthew (committee member).
Subjects/Keywords: gravitational lensing; galaxy clusters; Astronomy; Science
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APA ·
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MLA ·
Vancouver ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Johnson, T. (2018). Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/144156
Chicago Manual of Style (16th Edition):
Johnson, Traci. “Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing.” 2018. Doctoral Dissertation, University of Michigan. Accessed January 22, 2021.
http://hdl.handle.net/2027.42/144156.
MLA Handbook (7th Edition):
Johnson, Traci. “Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing.” 2018. Web. 22 Jan 2021.
Vancouver:
Johnson T. Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/2027.42/144156.
Council of Science Editors:
Johnson T. Focusing Cosmic Telescopes: Quantifying the Systematics of Strong Lensing Mass Models in the Era of Precision Lensing. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/144156
Mahatma Gandhi University
14.
Vinu, V.
Morphological evolution in galaxy clusters a quantitative
approach; -.
Degree: Physics, 2013, Mahatma Gandhi University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/13241
► Galaxies form a beautiful part of our complex Universe. The study of this component gives invaluable information on the formation and evolution of the visible…
(more)
▼ Galaxies form a beautiful part of our complex
Universe. The study of this component gives invaluable information
on the formation and evolution of the visible structures of the
Universe. As in the case of other objects, the study of galaxies
also started with their classification in the beginning of the 20th
century. Using the largest telescope at that time, Edwin Hubble in
the 1920s classified galaxies and his system forms the basis of
galaxy classification even today. Astronomers interpreted the
existence of the Hubble Tuning Fork diagram as one which reflects
the sequence of formation and evolution of galaxies where
ellipticals form first and flatten into disk systems as the
Universe evolves. Modern telescopes can look back to very early
stages of Universe and find that the Hubble system breaks down as
these telescopes find more and more peculiar galaxies at high
redshifts which cannot be accommodated into the Hubble system.
These observations lead to another important era in modern
astronomy. Modern telescopes produce deep images of the sky
necessitating the analysis of millions of galaxy images. We develop
an automated tool to perform such an analysis and use it to study
the evolution of galaxies. It was found that the Hubble system
correlates well with many physical properties of galaxies. For
example, elliptical galaxies are redder, as these galaxies contain
an old, low mass stellar population, compared to spiral galaxies.
It can be seenth at a correlation exists between the bulge-to-total
light ratio (B=T) and the Hubble type of galaxies where a disk
galaxy can be identified with B=T _ 0 and an elliptical galaxy can
be parameterized by B=T _ 1. The classification of galaxies on the
basis of B=T has evolved as a powerful tool in the recent past
since it needs considerably less human intervention. The two
dimensional bulge disk decomposition technique is not only useful
in finding B=T, but is also powerful enough to accurately estimate
the structural parameters of both the bulge and the disk
components
Bibliography p. 128-137
Advisors/Committee Members: Indulekha, K, Kembhavi, Ajit K.
Subjects/Keywords: Physics; Galaxies; Hubble system; galaxy clusters; Python
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Vinu, V. (2013). Morphological evolution in galaxy clusters a quantitative
approach; -. (Thesis). Mahatma Gandhi University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/13241
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Vinu, V. “Morphological evolution in galaxy clusters a quantitative
approach; -.” 2013. Thesis, Mahatma Gandhi University. Accessed January 22, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/13241.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Vinu, V. “Morphological evolution in galaxy clusters a quantitative
approach; -.” 2013. Web. 22 Jan 2021.
Vancouver:
Vinu V. Morphological evolution in galaxy clusters a quantitative
approach; -. [Internet] [Thesis]. Mahatma Gandhi University; 2013. [cited 2021 Jan 22].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13241.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Vinu V. Morphological evolution in galaxy clusters a quantitative
approach; -. [Thesis]. Mahatma Gandhi University; 2013. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13241
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Waterloo
15.
Joshi, Gandhali.
Substructure and Gas Clumping in the Outskirts of Abell 133.
Degree: 2013, University of Waterloo
URL: http://hdl.handle.net/10012/7837
► Galaxy clusters are powerful tools for studying various astrophysical principles. Gas accreting onto the cluster is heated to 107-108 K through adiabatic compression and shocks,…
(more)
▼ Galaxy clusters are powerful tools for studying various astrophysical principles. Gas accreting onto the cluster is heated to 107-108 K through adiabatic compression and shocks, making clusters highly luminous in X-ray imaging. Measurements of the gas density and temperature profiles can be used to calculate the gas mass fraction fgas, which is expected to closely match the cosmic baryon fraction Ωb/Ωm. Recent observations have found entropy profiles in cluster outskirts that are shallower than predicted and values of fgas that are higher than the Universal baryon fraction inferred from the Cosmic Microwave Background (CMB). Abell 133 was an ideal candidate for studying this phenomenon, since it had recently been observed in a wide (R≈30') Chandra mosaic with an exposure time of ∼2 Ms. The X-ray imaging was combined with existing optical imaging from the Canada-France-Hawaii Telescope (CFHT) and spectroscopy obtained from the Magellan telescope, to search for any possible gas clumps and to study their properties.
The photometric analysis yielded over 3200 red sequence galaxies to a depth of r'=22.5, which were used to create a Gaussian smoothed intensity map and a significance map of the cluster (compared to CFHT Legacy Survey data). About 6 significant overdensities were detected in the significance map, although these did not fully correspond to contours obtained from the X-ray image. Spectroscopy obtained on the cluster yielded ∼700 secure redshifts, of which about 180 were cluster members. This included data from the NOAO Fundamental Plane Survey (NFPS) and the 6 Degree Field Galaxy Survey (6dFGS). We found a cluster redshift of z=0.0561±0.0002 and a velocity dispersion of σ=743±43 km/s. The dynamical analysis gave a virial radius of rv=1.44±0.03 Mpc and a virial mass of Mv=(5.9±0.8)×1014 Msun. We also found values of R500=1.21±0.07 Mpc and M500=(5.3±0.9)×1014 Msun for γ=1/3 and R500=0.99±0.05 Mpc and M500=(2.9±0.5)×1014 Msun for γ=1/2, where γ is a parameter related to the assumed density profile and the velocity anisotropy.
About 30 overdensities with a radius Rc≥30" were detected as gas clumps on the X-ray image. The galaxy distribution in these clumps was analyzed, both for the stacked signal as well as the individual clumps, in ten parallel colour-magnitude bands to find any significant red sequences associated with them. Most of these clumps appeared to be background systems, some consisting of 1-2 galaxies, others being small groups or clusters. Only 2-3 clumps appeared to be associated with the cluster itself. This suggests that the cluster density profile is actually quite smooth, which may not agree with recent numerical simulations. Further studies are required to determine if the cluster density distribution is consistent with what is predicted and the nature of the background systems.
Subjects/Keywords: Galaxy clusters; Gas clumping; Cluster outskirts
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Joshi, G. (2013). Substructure and Gas Clumping in the Outskirts of Abell 133. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/7837
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Joshi, Gandhali. “Substructure and Gas Clumping in the Outskirts of Abell 133.” 2013. Thesis, University of Waterloo. Accessed January 22, 2021.
http://hdl.handle.net/10012/7837.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Joshi, Gandhali. “Substructure and Gas Clumping in the Outskirts of Abell 133.” 2013. Web. 22 Jan 2021.
Vancouver:
Joshi G. Substructure and Gas Clumping in the Outskirts of Abell 133. [Internet] [Thesis]. University of Waterloo; 2013. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10012/7837.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Joshi G. Substructure and Gas Clumping in the Outskirts of Abell 133. [Thesis]. University of Waterloo; 2013. Available from: http://hdl.handle.net/10012/7837
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
16.
Rude, Cody Millard.
Tracking Star Formation In Dwarf Cluster Galaxies.
Degree: PhD, Physics & Astrophysics, 2015, University of North Dakota
URL: https://commons.und.edu/theses/1829
► The evolution of galaxies in dense environments can be affected by close encounters with neighboring galaxies and interactions with the intracluster medium (ICM). Dwarf…
(more)
▼ The evolution of galaxies in dense environments can be affected by close encounters with neighboring galaxies and interactions with the intracluster medium (ICM). Dwarf galaxies may be especially susceptible to these effects due to their low mass. The goal of my dissertation research is to look for signs of star formation in cluster dwarf galaxies by measuring and comparing the r- and u-band luminosity functions of 15 low redshift Abell
galaxy clusters using archival data from the Canada-France-Hawaii Telescope (CFHT). Luminosity functions, dwarf-to-giant ratios, and blue fractions are measured in four cluster-centric annuli from stacked cluster data. To account for differences in cluster optical richness, each cluster is scaled according to r200, where r200 is the radius of a sphere, centered on the cluster, whose average density is 200 times the critical density of the universe. The outer region of the cluster sample shows an increase in the faint-end slope of the u-band luminosity function relative to the r-band, indicating star formation in dwarf galaxies. The blue fraction for dwarf galaxies steadily rises with increasing cluster-centric radii. The change in the blue fraction of giant galaxies also increases, but at a lower rate. Additionally, the inner regions of
clusters ranging from 0.185 < z < 0.7 from the “Cluster Lensing and Supernova survey with Hubble (CLASH)” are used to generate blue- and red-band luminosity functions, dwarf-to-giant ratios, and blue fractions. Comparisons of the inner region of the CLASH and CFHT
clusters show an increase in the blue fraction of dwarf galaxies with redshift that is not present in giant galaxies.
Advisors/Committee Members: Wayne Barkhouse.
Subjects/Keywords: Dwarf Galaxies; Galaxy Clusters; Star Formation
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APA (6th Edition):
Rude, C. M. (2015). Tracking Star Formation In Dwarf Cluster Galaxies. (Doctoral Dissertation). University of North Dakota. Retrieved from https://commons.und.edu/theses/1829
Chicago Manual of Style (16th Edition):
Rude, Cody Millard. “Tracking Star Formation In Dwarf Cluster Galaxies.” 2015. Doctoral Dissertation, University of North Dakota. Accessed January 22, 2021.
https://commons.und.edu/theses/1829.
MLA Handbook (7th Edition):
Rude, Cody Millard. “Tracking Star Formation In Dwarf Cluster Galaxies.” 2015. Web. 22 Jan 2021.
Vancouver:
Rude CM. Tracking Star Formation In Dwarf Cluster Galaxies. [Internet] [Doctoral dissertation]. University of North Dakota; 2015. [cited 2021 Jan 22].
Available from: https://commons.und.edu/theses/1829.
Council of Science Editors:
Rude CM. Tracking Star Formation In Dwarf Cluster Galaxies. [Doctoral Dissertation]. University of North Dakota; 2015. Available from: https://commons.und.edu/theses/1829
17.
Wiener, Joshua.
Cosmic Ray Dynamics in Galaxies and Galaxy Clusters.
Degree: 2015, University of California – eScholarship, University of California
URL: http://www.escholarship.org/uc/item/8v85b8vj
► Cosmic rays comprise a significant amount of energy in galaxy clusters, and are as energetically important in galaxies as the thermal gas. A careful treatment…
(more)
▼ Cosmic rays comprise a significant amount of energy in galaxy clusters, and are as energetically important in galaxies as the thermal gas. A careful treatment of cosmic ray transport is necessary to predict dynamics (such as CR driven winds) based on the radio observations which indicate their abundance. Yet the physics of cosmic ray transport are not very well understood. In this dissertation I will discuss how cosmic rays travel through and couple energetically with magnetized plasma, focusing specifically on the effects of streaming and heating in cluster and galactic environments.
Subjects/Keywords: Astrophysics; cosmic rays; galaxies; galaxy clusters
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APA (6th Edition):
Wiener, J. (2015). Cosmic Ray Dynamics in Galaxies and Galaxy Clusters. (Thesis). University of California – eScholarship, University of California. Retrieved from http://www.escholarship.org/uc/item/8v85b8vj
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wiener, Joshua. “Cosmic Ray Dynamics in Galaxies and Galaxy Clusters.” 2015. Thesis, University of California – eScholarship, University of California. Accessed January 22, 2021.
http://www.escholarship.org/uc/item/8v85b8vj.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wiener, Joshua. “Cosmic Ray Dynamics in Galaxies and Galaxy Clusters.” 2015. Web. 22 Jan 2021.
Vancouver:
Wiener J. Cosmic Ray Dynamics in Galaxies and Galaxy Clusters. [Internet] [Thesis]. University of California – eScholarship, University of California; 2015. [cited 2021 Jan 22].
Available from: http://www.escholarship.org/uc/item/8v85b8vj.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wiener J. Cosmic Ray Dynamics in Galaxies and Galaxy Clusters. [Thesis]. University of California – eScholarship, University of California; 2015. Available from: http://www.escholarship.org/uc/item/8v85b8vj
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
18.
Barber, Andrew J.
The weak gravitational lensing of light in cosmological N-body simulations.
Degree: PhD, 1999, University of Sussex
URL: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298651
Subjects/Keywords: 523.01; Galaxy clusters
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APA (6th Edition):
Barber, A. J. (1999). The weak gravitational lensing of light in cosmological N-body simulations. (Doctoral Dissertation). University of Sussex. Retrieved from https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298651
Chicago Manual of Style (16th Edition):
Barber, Andrew J. “The weak gravitational lensing of light in cosmological N-body simulations.” 1999. Doctoral Dissertation, University of Sussex. Accessed January 22, 2021.
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298651.
MLA Handbook (7th Edition):
Barber, Andrew J. “The weak gravitational lensing of light in cosmological N-body simulations.” 1999. Web. 22 Jan 2021.
Vancouver:
Barber AJ. The weak gravitational lensing of light in cosmological N-body simulations. [Internet] [Doctoral dissertation]. University of Sussex; 1999. [cited 2021 Jan 22].
Available from: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298651.
Council of Science Editors:
Barber AJ. The weak gravitational lensing of light in cosmological N-body simulations. [Doctoral Dissertation]. University of Sussex; 1999. Available from: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298651
Victoria University of Wellington
19.
Duchesne, Stefan.
Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field.
Degree: 2017, Victoria University of Wellington
URL: http://hdl.handle.net/10063/6248
► Low-frequency radio imaging of the southern sky has become available with the advent of the Murchison Widefield Array (MWA). The topic of this thesis is…
(more)
▼ Low-frequency radio imaging of the southern sky has become available with the advent of the Murchison Widefield Array (MWA). The topic of this thesis is the study of extended, low-frequency radio emission, with a primary focus on the non-thermal synchrotron emission associated with the intra-cluster medium (ICM) of
galaxy clusters. We do not limit the study to such emission, however, and investigate a small sample of other interesting and extended radio emission from objects in the southern sky.
A significant portion of this work is invested in detecting, and characterising, extended, diffuse radio emission from
galaxy clusters within a 45 degree by 45 degree region of the southern sky centred on R.A. = 0 hours, decl. = -27 degrees. This field is chosen as a deep MWA image has been made available which is sensitive to extended structures. Within the field we search for low-frequency, diffuse cluster emission, previously detected or otherwise. In doing so we find 34 diffuse radio sources, 3 of which are newly detected haloes, 1 newly detected relic with many new candidates of each. Further, we detect a new phoenix candidate as well as 2 candidate dead radio galaxies at the centre of
clusters. We confirm previous observations of such emission as well, and measure properties such as their integrated flux densities, spectral indices, and sizes where possible. We compare our sample of haloes with previously detected haloes and revisit established scaling relations of the radio halo power with the cluster X-ray luminosity and mass. We find that both scaling relations are consistent with previous findings despite the increase in sample size, though note that the raw scatter in the data for best-fitting parameters increases with increase in sample size. In this, we demonstrate the utility of low-frequency radio telescopes like the MWA in detecting such emission, showing that the MWA is pushing into higher-redshift, lower-mass systems, though we caution that the low resolution of the MWA can work against us.
We follow-up on two
galaxy clusters found to host extended emission - Abell S1136 and Abell S1063. In the case of Abell S1136 we observe the emission at its centre with the Australia Telescope Compact Array (ATCA) and determine the presence of a core, suggesting the emission to be that of an ancient episode of an active galactic nucleus in the central elliptical of the cluster, ESO 470-G020. After reducing archival ATCA data for Abell S1063 we find no evidence of a halo and consider the source to be constructed of blended point sources. We close with a description of a strong double-lobed radio source associated with a non-elliptical host ESO 472-G013, likely a spiral or irregular
galaxy, that was found serendipitously whilst searching for diffuse cluster emission. We explore the host within the context of star-formation, and consider the possible origins of the AGN and lobes due to interaction with either the nearby spiral, ESO 472-G012, or a past or ongoing merger event.
Advisors/Committee Members: Johnston-Hollitt, Melanie.
Subjects/Keywords: Radio astronomy; Galaxy clusters; Synchrotron emission
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Manager
APA (6th Edition):
Duchesne, S. (2017). Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field. (Masters Thesis). Victoria University of Wellington. Retrieved from http://hdl.handle.net/10063/6248
Chicago Manual of Style (16th Edition):
Duchesne, Stefan. “Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field.” 2017. Masters Thesis, Victoria University of Wellington. Accessed January 22, 2021.
http://hdl.handle.net/10063/6248.
MLA Handbook (7th Edition):
Duchesne, Stefan. “Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field.” 2017. Web. 22 Jan 2021.
Vancouver:
Duchesne S. Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field. [Internet] [Masters thesis]. Victoria University of Wellington; 2017. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10063/6248.
Council of Science Editors:
Duchesne S. Diffuse Extragalactic Emission at Low Frequencies within the Epoch of Reionization 0-hour Field. [Masters Thesis]. Victoria University of Wellington; 2017. Available from: http://hdl.handle.net/10063/6248
University of the Western Cape
20.
Randriamampandry, Solohery Mampionona.
Far-infrared-radio relations in clusters and groups at intermediate redshift
.
Degree: 2014, University of the Western Cape
URL: http://hdl.handle.net/11394/4221
► In this thesis, we present a multi-wavelength analysis of star-forming galaxies to shed new light on the evolution of the far-IR-radio relations in intermediate redshift…
(more)
▼ In this thesis, we present a multi-wavelength analysis of star-forming galaxies to shed new light on the evolution of the far-IR-radio relations in intermediate redshift (0.3 < z < 0.6)
galaxy clusters and
galaxy groups. The far-infrared (far-IR) emission from galaxies is dominated by thermal dust emission. The radio emission at 1.4 GHz is predominantly produced by non-thermal synchrotron radiation. The underlying mechanisms, which drive the far-IR-radio correlation, are believed to arise from massive star formation. A number of studies have investigated the relationship as a function of redshift in the field and have found no evolution out to at least z _ 2, however few works have been done in
galaxy clusters. In nearby
clusters, the median logarithmic ratio of the far-IR to radio luminosity is qFIR = 2.07_0.74, which is lower than the value found in the field, and there is an indication of an enhancement of radio emission relative to the far-IR emission. Understanding the properties of the far-IR-radio correlation in a sample of distant and massive cluster and groups plays an important role in understanding the physical processes in these systems.
We have derived total infrared luminosities for a sample of cluster, group, and field galaxies through an empirical relation based on Spitzer MIPS 24 _m photometry. The radio flux densities were measured from deep Very Large Array 1.4 GHz radio continuum observations. We have studied the properties of the far-IR-radio correlation of galaxies at intermediate redshift
clusters by comparing the relationship of these galaxies to that of low redshift
clusters. We have also examined the properties of the galaxies showing radio excess to determine the extent that
galaxy type or environment may explain the radio excess in
galaxy clusters. We find that the ratio of far-IR to radio luminosity for galaxies in an intermediate redshift cluster to be qFIR = 1.72_0.63. This value is comparable to that measured in low redshift
clusters. A higher fraction of galaxies in
clusters show an excess in their radio fluxes when compared to low redshift
clusters, and corroborates previous evidence of a cluster enhancement of radio excess sources at this earlier epoch as well. We have also investigated the properties of the far-IR-radio correlation for a sample of
galaxy groups in the COSMOS field. We find a lower percentage of radio-excess sources in groups as compared to
clusters. This provides preliminary evidence that the number of radioexcess sources may depend on
galaxy environment. We also find that a larger fraction of radio-excess sources in
clusters are red sequence galaxies.
Advisors/Committee Members: Crawford, Steven (advisor), Cress, Catherine (advisor).
Subjects/Keywords: Galaxy clusters;
Spectroscopy;
Star-forming galaxies
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APA ·
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APA (6th Edition):
Randriamampandry, S. M. (2014). Far-infrared-radio relations in clusters and groups at intermediate redshift
. (Thesis). University of the Western Cape. Retrieved from http://hdl.handle.net/11394/4221
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Randriamampandry, Solohery Mampionona. “Far-infrared-radio relations in clusters and groups at intermediate redshift
.” 2014. Thesis, University of the Western Cape. Accessed January 22, 2021.
http://hdl.handle.net/11394/4221.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Randriamampandry, Solohery Mampionona. “Far-infrared-radio relations in clusters and groups at intermediate redshift
.” 2014. Web. 22 Jan 2021.
Vancouver:
Randriamampandry SM. Far-infrared-radio relations in clusters and groups at intermediate redshift
. [Internet] [Thesis]. University of the Western Cape; 2014. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/11394/4221.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Randriamampandry SM. Far-infrared-radio relations in clusters and groups at intermediate redshift
. [Thesis]. University of the Western Cape; 2014. Available from: http://hdl.handle.net/11394/4221
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Victoria
21.
Spengler, Chelsea.
Nuclear star clusters in the Virgo Cluster of galaxies.
Degree: Department of Physics and Astronomy, 2018, University of Victoria
URL: https://dspace.library.uvic.ca//handle/1828/10356
► It is readily accepted that many galaxies are inhabited by dense, compact objects deep in their centres, manifesting as supermassive black holes (SMBHs) and/or nuclear…
(more)
▼ It is readily accepted that many galaxies are inhabited by dense, compact objects deep in their centres, manifesting as supermassive black holes (SMBHs) and/or nuclear star
clusters (NSCs). Their widespread presence and apparent similar scaling relations with properties of their hosts implies that SMBHs and NSCs are two related flavours of central massive object (CMO) that play essential roles in their hosts' evolution. However, the formation conditions required for CMOs, the exact behaviour of these scaling relations, and the interplay among CMOs, their hosts, and the environment remain open questions, and are particularly poorly understood in lower-mass galaxies where NSCs are the dominant CMO. This thesis contributes to the answers to these questions through a study of ultraviolet, optical, and near-infrared imaging of NSCs and galaxies provided by three recent surveys of the Virgo Cluster: the ACS Virgo Cluster Survey (ACSVCS), Virgo Redux, and the Next Generation Virgo Cluster Survey (NGVS).
The analysis of the masses, ages and metallicities for a choice sample of 39 nucleated early-type galaxies with the complete wavelength coverage provided from all three surveys supports complex formation scenarios for the NSCs, involving a stochastic mix of dissipative and dissipationless processes. However, trends in the structural parameters of the NSCs show that the brightest NSCs tend to be flattened, suggesting that NSC formation may be dominated by dissipative processes in more massive systems, compared to dissipationless star cluster infall dominating in less massive galaxies. A comparison of these photometrically-derived stellar population parameters with those from available high quality optical spectra shows that estimated metallicities from the two samples are consistent, which is encouraging for using broadband photometry to derive stellar population parameters when spectroscopy is not feasible.
Probing the effects of environment with the unprecedented sample available in the NGVS first requires a method to identify distinct environments through the detection of substructures in an objective, self-consistent way. I introduce a novel clustering algorithm and validate its performance using NGVS and 12 Virgo analogues from the Illustris simulations. This validation also permits a test of the lambda cold dark matter (ΛCDM) model's ability to replicate observed structures on cluster-sized spatial scales. The algorithm successfully recovers already-known Virgo substructures along with multiple intriguing new substructure discoveries, verified using available recessional velocities and distances from surface brightness fluctuations. Additional tests tentatively suggest that ΛCDM does not reproduce the level of substructure in Virgo; however, an expanded sample of observed
clusters is necessary for a statistically robust conclusion.
Lastly, I expand the analysis of structural and photometric parameters to encompass all NSCs and galaxies with measured parameters in the NGVS, and combine this with the substructure…
Advisors/Committee Members: Côté, Patrick (supervisor), Willis, Jon (supervisor).
Subjects/Keywords: astronomy; galaxy evolution; stellar populations; star clusters
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APA (6th Edition):
Spengler, C. (2018). Nuclear star clusters in the Virgo Cluster of galaxies. (Thesis). University of Victoria. Retrieved from https://dspace.library.uvic.ca//handle/1828/10356
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Spengler, Chelsea. “Nuclear star clusters in the Virgo Cluster of galaxies.” 2018. Thesis, University of Victoria. Accessed January 22, 2021.
https://dspace.library.uvic.ca//handle/1828/10356.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Spengler, Chelsea. “Nuclear star clusters in the Virgo Cluster of galaxies.” 2018. Web. 22 Jan 2021.
Vancouver:
Spengler C. Nuclear star clusters in the Virgo Cluster of galaxies. [Internet] [Thesis]. University of Victoria; 2018. [cited 2021 Jan 22].
Available from: https://dspace.library.uvic.ca//handle/1828/10356.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Spengler C. Nuclear star clusters in the Virgo Cluster of galaxies. [Thesis]. University of Victoria; 2018. Available from: https://dspace.library.uvic.ca//handle/1828/10356
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Princeton University
22.
Chisari, Nora Elisa.
Clusters, brightest cluster galaxies and galaxy alignments
.
Degree: PhD, 2014, Princeton University
URL: http://arks.princeton.edu/ark:/88435/dsp013484zk139
► This thesis develops two main topics related to the study of the large-scale structure of the Universe. The first one is the intrinsic alignment of…
(more)
▼ This thesis develops two main topics related to the study of the large-scale structure of the Universe. The first one is the intrinsic alignment of galaxies. These are correlations between the shapes and orientations of galaxies that arise mainly as a consequence of tidal forces across a large range of scales. I use the tidal alignment model to predict how the intrinsic alignment of Luminous Red Galaxies could in the future provide constraints on the Baryon Acoustic Oscillation scale, a standard ruler for measuring the expansion of the Universe. I also show that primordial signatures of inflation can translate into a non-Gaussian bias in the correlation of the intrinsic shapes of galaxies, which could be observed with future surveys.
The second main topic discussed in this thesis is
clusters of galaxies. I use data from the Sloan Digital Sky Survey and a public catalog of
galaxy clusters to estimate the alignment of galaxies around groups and
clusters of galaxies. The novelty of this work is mainly in the method for estimating the alignment signal. In photometric surveys, the redshift uncertainty is large compared to the size of a cluster, making the distinction between galaxies in the cluster and in the background very challenging. In the method developed here, each
galaxy is assigned a posterior probability distribution function of its redshift to separate the alignment component from the gravitational lensing of galaxies in the background.
Among the galaxies that make up a cluster, Brightest Cluster Galaxies stand out by their luminosity. I study the connection between these galaxies and other ellipticals to understand the physics of their formation. Finally, I re-develop the Adaptive Matched Filter method for finding
clusters in spectroscopic and photometric surveys to include a new treatment of the distances to galaxies. Again, I model the distance to each
galaxy using a redshift posterior and propose other modifications to the algorithm that will be of use to upcoming photometric surveys.
Advisors/Committee Members: Strauss, Michael A (advisor).
Subjects/Keywords: Brightest cluster galaxies;
Clusters;
Galaxy alignments
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APA ·
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Manager
APA (6th Edition):
Chisari, N. E. (2014). Clusters, brightest cluster galaxies and galaxy alignments
. (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp013484zk139
Chicago Manual of Style (16th Edition):
Chisari, Nora Elisa. “Clusters, brightest cluster galaxies and galaxy alignments
.” 2014. Doctoral Dissertation, Princeton University. Accessed January 22, 2021.
http://arks.princeton.edu/ark:/88435/dsp013484zk139.
MLA Handbook (7th Edition):
Chisari, Nora Elisa. “Clusters, brightest cluster galaxies and galaxy alignments
.” 2014. Web. 22 Jan 2021.
Vancouver:
Chisari NE. Clusters, brightest cluster galaxies and galaxy alignments
. [Internet] [Doctoral dissertation]. Princeton University; 2014. [cited 2021 Jan 22].
Available from: http://arks.princeton.edu/ark:/88435/dsp013484zk139.
Council of Science Editors:
Chisari NE. Clusters, brightest cluster galaxies and galaxy alignments
. [Doctoral Dissertation]. Princeton University; 2014. Available from: http://arks.princeton.edu/ark:/88435/dsp013484zk139
University of Illinois – Urbana-Champaign
23.
Song, Jeeseon.
Early Type Galaxies And Reliable Galaxy Cluster Selection.
Degree: PhD, 0333, 2011, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/18515
► In an era of precision cosmology, clusters of galaxies are the natural consequences under the hierarchical scenario, within which clusters directly encapsulate the history of…
(more)
▼ In an era of precision cosmology,
clusters of galaxies are the natural consequences under the hierarchical scenario, within which
clusters directly encapsulate the history of structure formation. Thus, determining the mass distribution of
clusters as a function of redshift enables fundamental tests of this structure formation process. My projects have initially been motivated by an intellectual inquiry into how we can effectively and accurately analyze data from large cluster surveys, such as the South Pole Telescope (SPT), the Blanco Cosmology Survey (BCS) and the upcoming Dark Energy Survey (DES), which now extends to the
galaxy formation and evolution studies. Through this thesis project followed by immediate extension of the thesis, I, therefore, aim to achieve three distinct, but highly inter-related main research goals: (1) creating mock catalogs that represent the universe well enough, (2) employing these mock catalogs to quantitatively characterize optical selection tools and then applying those well understood selection tools to large new surveys, and (3) exploring the underlying physics of
galaxy population and property evolution over the cosmic time.
Clusters of galaxies are an important laboratory for exploring
galaxy formation and evolution. Automatic data analysis tools, such as cluster finding algorithms or mass and photometric redshift estimators, need to be tested prior to their use. We have launched a project to create realistic mock
galaxy catalogs that will perform these tests accurately. This thesis project also includes development of tools to characterize
clusters of galaxies, such as a red-sequence redshift estimator and an optical richness estimator. We also explore one of the candidates of contamination in cluster finding in sub-mm wavelength. The scientific goals to have been achieved are to build a realistic mock catalog on which several analysis tools are tested to better understand our ability to make accurate measurements; to develop an independent redshift and optical richness estimators with their applications to real
clusters and to understand their systematics better to reduce the scatter; and to address a cautionary point in sub-mm cluster finding due to radio galaxies that are associated with
clusters. These projects, in conjunction with each other, are demonstrated as crucial elements in constraining cosmological parameters to understand the evolution of the universe.
Advisors/Committee Members: Mohr, Joseph J. (advisor), Mohr, Joseph J. (Committee Chair), Chu, You-Hua (committee member), Fields, Brian D. (committee member), Ricker, Paul M. (committee member), Thaler, Jonathan J. (committee member).
Subjects/Keywords: Galaxy Clusters; Cosmology; Large scale structure
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Song, J. (2011). Early Type Galaxies And Reliable Galaxy Cluster Selection. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/18515
Chicago Manual of Style (16th Edition):
Song, Jeeseon. “Early Type Galaxies And Reliable Galaxy Cluster Selection.” 2011. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 22, 2021.
http://hdl.handle.net/2142/18515.
MLA Handbook (7th Edition):
Song, Jeeseon. “Early Type Galaxies And Reliable Galaxy Cluster Selection.” 2011. Web. 22 Jan 2021.
Vancouver:
Song J. Early Type Galaxies And Reliable Galaxy Cluster Selection. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2011. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/2142/18515.
Council of Science Editors:
Song J. Early Type Galaxies And Reliable Galaxy Cluster Selection. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2011. Available from: http://hdl.handle.net/2142/18515
University of Minnesota
24.
Johnson, Andrew Richard.
Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields.
Degree: MS, Astrophysics, 2014, University of Minnesota
URL: http://hdl.handle.net/11299/165507
► Rotation measures (RMs), derived using polarized radio sources embedded in clusters, are commonly used to estimate magnetic field strengths in intra-cluster media(ICMs). To obtain these…
(more)
▼ Rotation measures (RMs), derived using polarized radio sources embedded in clusters, are commonly used to estimate magnetic field strengths in intra-cluster media(ICMs). To obtain these field values, assumptions are often invoked that involve: no RM contributions from the RM source, adequate sampling of the cluster ICM, and power law distributions of the magnetic power spectra. We explore the impact of such assumptions using synthetic RM measurements of the ICM of a dynamical cluster extracted from a magneto-hydrodynamic (MHD) cosmological simulation. We first explore the viability of estimating cluster magnetic fields using both RMs fully sampling the cluster as well as limited sampling using non-interacting RM sources placed within the cluster.We then evolve the cluster both with and without an interacting central active galactic nucleus (AGN) to examine how a radio source interacting with the surrounding ICM modifies the observed RMs. We applying a density dependent RM coherence length to our models and find that the magnetic field estimates are improved over models with a constant RM coherence length. We also suggest that a magnetic field model only need be characterized by a coherence length, the central dispersion value, and the scaling with density to effectively produce observed cluster RMs. However, uncertainties- predominantly due to large scale anisotropies- produce errors in the estimates of cluster magnetic fields that under ideal conditions are a factor of 50%. For sources that interact with the surrounding ICM, we find that the motions induced in the local ICM do not significantly alter the overall distribution of RMs observed in a "foreground screen". However, if the magnetic fields introduced by the radio source are sufficiently strong, non-negligible RM contributions attributed to ICM entrainment with the radio source plasma could contaminate RM observations making estimates of the undisturbed ICM magnetic fields perilous.
Subjects/Keywords: Galaxy Clusters; Magnetic Fields; Rotation Measures
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APA (6th Edition):
Johnson, A. R. (2014). Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields. (Masters Thesis). University of Minnesota. Retrieved from http://hdl.handle.net/11299/165507
Chicago Manual of Style (16th Edition):
Johnson, Andrew Richard. “Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields.” 2014. Masters Thesis, University of Minnesota. Accessed January 22, 2021.
http://hdl.handle.net/11299/165507.
MLA Handbook (7th Edition):
Johnson, Andrew Richard. “Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields.” 2014. Web. 22 Jan 2021.
Vancouver:
Johnson AR. Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields. [Internet] [Masters thesis]. University of Minnesota; 2014. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/11299/165507.
Council of Science Editors:
Johnson AR. Rotation measures in galaxy clusters from background and embedded sources: estimating the cluster magnetic fields. [Masters Thesis]. University of Minnesota; 2014. Available from: http://hdl.handle.net/11299/165507
University of Southern California
25.
Mak, Suet-Ying.
Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect.
Degree: PhD, Physics, 2013, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/312976/rec/1673
► In this work, we present various studies to forecast the power of the galaxy clusters detected by the Sunyaev-Zel'dovich (SZ) effect in constraining cosmological models.…
(more)
▼ In this work, we present various studies to forecast
the power of the
galaxy clusters detected by the Sunyaev-Zel'dovich
(SZ) effect in constraining cosmological models. The SZ effect is
regarded as one of the new and promising technique to identify and
study cluster physics. With the latest data being released in
recent years from the SZ telescopes, it is essential to explore
their potentials in providing cosmological information and
investigate their relative strengths with respect to
galaxy cluster
data from X-ray and optical, as well as other cosmological probes
such as Cosmic Microwave Background (CMB). ❧ One of the topics
regard resolving the debate on the existence of an anomalous large
scale bulk flow as measured from the kinetic SZ signal of
galaxy
clusters in the WMAP CMB data. We predict that if such measurement
is done with the latest CMB data from the Planck satellite, the
sensitivity will be improved by a factor of > 5 and thus be able
to provide an independent view of its existence. As it turns out,
the Planck data, when using the technique developed in this work,
find that the observed bulk flow amplitude is consistent with those
expected from the ΛCDM, which is in clear contradiction to the
previous claim of a significant bulk flow detection in the WMAP
data. ❧ We also forecast on the capability of the ongoing and
future cluster surveys identified through thermal SZ (tSZ) in
constraining three extended models to the ΛCDM model: modified
gravity f(R) model, primordial non-Gaussianity of density
perturbation, and the presence of massive neutrinos. We do so by
employing their effects on the cluster number count and power
spectrum and using Fisher Matrix analysis to estimate the errors on
the model parameters. We find that SZ cluster surveys can provide
vital complementary information to those expected from non-cluster
probes. Our results therefore give the confidence for pursuing
these extended cosmological models with SZ
clusters.
Advisors/Committee Members: Pierpaoli, Elena (Committee Chair), Johnson, Clifford V. (Committee Member), Dappen, Werner (Committee Member), Däppen, Werner (Committee Member), Daeppen, Werner (Committee Member), Bars, Itzhak (Committee Member), Columbo, Loris (Committee Member), Bonahon, Francis (Committee Member).
Subjects/Keywords: cosmology; galaxy clusters; Sunyaev-Zel'; dovich effect
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APA (6th Edition):
Mak, S. (2013). Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/312976/rec/1673
Chicago Manual of Style (16th Edition):
Mak, Suet-Ying. “Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect.” 2013. Doctoral Dissertation, University of Southern California. Accessed January 22, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/312976/rec/1673.
MLA Handbook (7th Edition):
Mak, Suet-Ying. “Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect.” 2013. Web. 22 Jan 2021.
Vancouver:
Mak S. Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect. [Internet] [Doctoral dissertation]. University of Southern California; 2013. [cited 2021 Jan 22].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/312976/rec/1673.
Council of Science Editors:
Mak S. Cosmological study with galaxy clusters detected by the
Sunyaev-Zel'dovich effect. [Doctoral Dissertation]. University of Southern California; 2013. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/312976/rec/1673
University of Arizona
26.
Just, Dennis William.
The Influence of Environment on Galaxy Evolution
.
Degree: 2012, University of Arizona
URL: http://hdl.handle.net/10150/265357
► We study the influence of environment on galaxy evolution by focusing on two galaxy types known for their connection to dense environments, S0s and Brightest…
(more)
▼ We study the influence of environment on
galaxy evolution by focusing on two
galaxy types known for their connection to dense environments, S0s and Brightest Cluster Galaxies (BCGs). Our goal is to identify the mechanisms responsible for the properties of galaxies in groups and
clusters. We first examine the effects of environment on S0 formation over the past ~7 Gyr by tracing the increasing S0 fraction in
clusters at two mass scales. We find the build-up of S0s driven by groups/
clusters with velocity dispersions σ ≲ 750 km s⁻¹, suggesting mechanisms that operate most efficiently via slow encounters (e.g., mergers and tidal interactions) form S0s.With less-massive halos identified as the site for S0 formation, we test whether another route to S0 formation exists, not in isolated groups but rather in a system of four merging groups (SG1120). We place limits on how recent the S0s in that system could have formed, and finding no star formation, conclude they formed ≳ 1 Gyr prior to SG1120's current configuration, when they were in more isolated groups. We next explore cluster outskirts to constrain the number of infalling galaxies that need to be transformed and whether that process has already begun. We find the red fraction of infalling galaxies is elevated relative to the field, and that red galaxies are more clustered than blue ones, a signature of "pre-processing". We disentangle the relative strength of global versus local environment on
galaxy transformation by comparing the correlation of red fraction with radius and local density. We find that both parameters are connected with the red fraction of galaxies. Finally, we measure the frequency of galaxies falling into the cluster that are bright enough to supplant the current BCG and compare the results to models. We find in ~ 85% of our
clusters that the BCG is secure and remains in its priviledged state until z ~ 0.From these analyses, we find that intermediate density environments (groups and cluster outskirts) are the key site to forming S0 galaxies, and that BCGs, while not exclusively a cluster phenomenon, are well established by the redshifts we explore.
Advisors/Committee Members: Zaritsky, Dennis (advisor), Dave, Romeel (committeemember), Olszewski, Edward (committeemember), Fan, Xiaohui (committeemember), Zaritsky, Dennis (committeemember), Zabludoff, Ann (committeemember).
Subjects/Keywords: Astronomy;
Clusters of Galaxies;
Galaxy Evolution
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Manager
APA (6th Edition):
Just, D. W. (2012). The Influence of Environment on Galaxy Evolution
. (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/265357
Chicago Manual of Style (16th Edition):
Just, Dennis William. “The Influence of Environment on Galaxy Evolution
.” 2012. Doctoral Dissertation, University of Arizona. Accessed January 22, 2021.
http://hdl.handle.net/10150/265357.
MLA Handbook (7th Edition):
Just, Dennis William. “The Influence of Environment on Galaxy Evolution
.” 2012. Web. 22 Jan 2021.
Vancouver:
Just DW. The Influence of Environment on Galaxy Evolution
. [Internet] [Doctoral dissertation]. University of Arizona; 2012. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10150/265357.
Council of Science Editors:
Just DW. The Influence of Environment on Galaxy Evolution
. [Doctoral Dissertation]. University of Arizona; 2012. Available from: http://hdl.handle.net/10150/265357
University of Arizona
27.
Wong, Kenneth Christopher.
Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
.
Degree: 2013, University of Arizona
URL: http://hdl.handle.net/10150/305760
► In this thesis, I explore how the environments of both galaxy and cluster-scale strong gravitational lenses affect studies of cosmology and the properties of the…
(more)
▼ In this thesis, I explore how the environments of both
galaxy and cluster-scale strong gravitational lenses affect studies of cosmology and the properties of the earliest galaxies.
Galaxy-scale lenses with measured time delays can be used to determine the Hubble constant, given an accurate lens model. However, perturbations from structures along the line of sight can introduce errors into the measurement. I use data from a survey towards known lenses in group environments to calculate the external shear in these systems, which is typically marginalized over in standard lens analyses. In three of six systems where I compare the independently-calculated environment shear to lens model shears, the quantities disagree at greater than 95% confidence. We explore possible sources of this disagreement. Using these data, I generate fiducial lines of sight and insert mock lenses with assumed input physical and cosmological parameters and find that those parameters can be recovered with ∼ 5-10% scatter when uncertainties in my characterization of the environment are applied. The lenses in groups have larger bias and scatter. I predict how well new time delay lenses from LSST will constrain H₀ and find that an ensemble of 500 quad lenses will recover H₀ with ∼ 2% bias with ∼ 0.3% precision. On larger scales,
galaxy cluster lenses can magnify the earliest galaxies into detectability. While past studies have focused on single massive
clusters, I investigate the properties of lines of sight, or "beams", containing multiple cluster-scale halos in projection. Even for beams of similar total mass, those with multiple halos have higher lensing cross sections on average. The optimal configurations for maximizing the cross section are also those that maximize faint z ∼ 10 detections. I present a new selection technique to identify beams in wide-area photometric surveys that contain high total masses and often multiple
clusters in projection as traced by luminous red galaxies. I apply this technique to the Sloan Digital Sky Survey and present the 200 most promising beams. Several are confirmed spectroscopically to be among the highest mass beams known with some containing multiple
clusters. These are among the best fields to search for faint high-redshift galaxies.
Advisors/Committee Members: Zabludoff, Ann I (advisor), Eisenstein, Daniel J. (committeemember), Frye, Brenda L. (committeemember), Fan, Xiaohui (committeemember), Marrone, Daniel P. (committeemember), Zabludoff, Ann I. (committeemember).
Subjects/Keywords: galaxies;
galaxy clusters;
gravitational lensing;
Astronomy;
cosmology
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wong, K. C. (2013). Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
. (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/305760
Chicago Manual of Style (16th Edition):
Wong, Kenneth Christopher. “Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
.” 2013. Doctoral Dissertation, University of Arizona. Accessed January 22, 2021.
http://hdl.handle.net/10150/305760.
MLA Handbook (7th Edition):
Wong, Kenneth Christopher. “Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
.” 2013. Web. 22 Jan 2021.
Vancouver:
Wong KC. Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
. [Internet] [Doctoral dissertation]. University of Arizona; 2013. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10150/305760.
Council of Science Editors:
Wong KC. Strong Gravitational Lensing as a Probe of Galaxy Evolution and Cosmology
. [Doctoral Dissertation]. University of Arizona; 2013. Available from: http://hdl.handle.net/10150/305760
University of Minnesota
28.
Garon, Avery.
The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution.
Degree: MS, Astrophysics, 2020, University of Minnesota
URL: http://hdl.handle.net/11299/216084
► In this thesis, I explore the dynamics of radio galaxies in galaxy clusters by studying the statistical influence of the intracluster medium on the morphology…
(more)
▼ In this thesis, I explore the dynamics of radio galaxies in galaxy clusters by studying the statistical influence of the intracluster medium on the morphology of radio galaxies, and the evolution of the electron populations within different galaxies and radio relics in Abell 2255. In Chapter 2, I study the impact of cluster environment on the morphology of a sample of 4304 extended radio galaxies from Radio Galaxy Zoo. A total of 87% of the sample lies within a projected 15 Mpc of an optically identified cluster. Brightest cluster galaxies (BCGs) are more likely than other cluster members to be radio sources, and are also moderately bent. The surface density as a function of separation from cluster center of non-BCG radio galaxies follows a power law with index -1.10+-0.03 out to 10 r_500 (~7 Mpc), which is steeper than the corresponding distribution for optically selected galaxies. Non-BCG radio galaxies are statistically more bent the closer they are to the cluster center. Within the inner 1.5 r_500 (~1 Mpc) of a cluster, non-BCG radio galaxies are statistically more bent in high-mass clusters than in low-mass clusters. Together, I find that non-BCG sources are statistically more bent in environments that exert greater ram pressure. I use the orientation of bent radio galaxies as an indicator of galaxy orbits and find that they are preferentially in radial orbits. Away from clusters, there is a large population of bent radio galaxies, limiting their use as cluster locators; however, they are still located within statistically overdense regions. I investigate the asymmetry in the tail length of sources that have their tails aligned along the radius vector from the cluster center, and find that the length of the inward-pointing tail is weakly suppressed for sources close to the center of the cluster. In Chapter 3, I present a deep and high resolution P-band (370 MHz) VLA observation of the central radio galaxies and relics in Abell 2255. Using L-band (1.5 GHz) data analyzed in Lame'e (2017), I generate maps of spectral index, alpha_PL, calculated between the two frequencies. I detect two new extended sources of very steep spectrum (alpha_PL < -2) radio emission near the center of the cluster. I analyze the spectral curvature of the Original Tailed Radio Galaxy (TRG), the Goldfish galaxy, and the NE radio relic. The spectrum of the TRG and Goldfish both exhibit curvature intermediate between a power law spectrum and the exponential cut-off spectrum of the Jaffe-Perola model (Jaffe & Perola, 1973). There are two thin filaments at the end of the TRG; filament F1 only has a reliable measurement of the spectrum at one position, and is consistent with having the same spectral shape as the tail itself; the spectrum of filament F2 has less curvature than the tail, and is consistent with a power law. This suggests that F2 has been reaccelerated by a shock in the ICM, which would also explain its morphology, although that does not work for F1. The southern component of the NE relic has values of alpha_PL ranging between -0.4…
Subjects/Keywords: galaxy clusters; intracluster medium; radio galaxies
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APA ·
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MLA ·
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CSE |
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Manager
APA (6th Edition):
Garon, A. (2020). The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution. (Masters Thesis). University of Minnesota. Retrieved from http://hdl.handle.net/11299/216084
Chicago Manual of Style (16th Edition):
Garon, Avery. “The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution.” 2020. Masters Thesis, University of Minnesota. Accessed January 22, 2021.
http://hdl.handle.net/11299/216084.
MLA Handbook (7th Edition):
Garon, Avery. “The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution.” 2020. Web. 22 Jan 2021.
Vancouver:
Garon A. The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution. [Internet] [Masters thesis]. University of Minnesota; 2020. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/11299/216084.
Council of Science Editors:
Garon A. The Dynamics of Radio Galaxies In Clusters: Morphological Interactions and Particle Evolution. [Masters Thesis]. University of Minnesota; 2020. Available from: http://hdl.handle.net/11299/216084
29.
Psychogyios, Alexandros.
Galaxy morphology in different environments.
Degree: 2018, University of Crete (UOC); Πανεπιστήμιο Κρήτης
URL: http://hdl.handle.net/10442/hedi/44308
► The present thesis is examining a few open topics of galaxy evolution due to their environment, based on the analysis of galaxy morphology using imagery…
(more)
▼ The present thesis is examining a few open topics of galaxy evolution due to their environment, based on the analysis of galaxy morphology using imagery in optical and near-IR wavelengths. Our study was focused on two distinct samples, and it is thus divided in two parts. The first part deals with the morphological classification of 89 luminous infrared galaxies (LIRGs), systems with total infrared emission brighter than 1011 L⊙, of the Great Observatories All-sky LIRG Survey (GOALS) sample, that have been imaged with the Hubble Space Telescope. GOALS is a complete subset of the IRAS Revised Bright Galaxy Sample (RBGS) and consists of 202 systems in the local Universe (z < 0.09). The activity in LIRGs is largely interaction triggered, with the progenitors observed to be gas-rich disk galaxies involved in primarily minor interactions (at the low luminosity end) or major merger events (at luminosities over 1012 L⊙: ULIRGs). These interactions drive inflows of gas which give rise to both intense nuclear star formation (with star formation rates, SFR ∼ 10 - 200 M⊙/yr) and Active Galactic Nuclei (AGN) activity. As such, LIRGs are ideal for studying star formation in extreme environments and the interplay between star formation and AGN. At the high LIR end, LIRGs represent the brief (∼ several 108 years) but energetic transformation of normal disk galaxies into elliptical and S0 galaxies. Improving our understanding on of these systems will be critical for similar studies of starbursts in cosmologically distant LIRGs which comprise the bulk of the IR energy density at z > 0.5. We used automatically calculated non-parametric coefficients (Gini and M20; the second order of light surface density) to quantify their morphology in the optical (B- and I-band) as well as in the infrared (H-band and 5.8μm). We explored the morphology of (U)LIRGs as a function of stellar mass (M⋆), infrared luminosity (LIR), star formation rate (SFR) and dust temperature (Tdust). We find that M20 is a better morphological tracer than Gini, as it allows us to distinguish systems that were formed by double systems from isolated and post-merger LIRGs. Our multi-wavelength analysis allows us to identify a region in the Gini-M20 parameter space where ongoing mergers reside, regardless of the band used. This particular region is best defined in the H-band, with minimal contamination from LIRGs in other stages. Exploring the distribution of our galaxies on the specific SFR (sSFR)-M20 plane, we also find a spatial decoupling between obscured and unobscured star formation. The sSFR is positively correlated with M20 when measured in the mid-infrared (star-bursting galaxies display more compact emission) while it is anti-correlated with the B-band- measured M20. This has important implications for high redshift surveys of dusty sources, where sizes of galaxies are routinely measured in the rest-frame ultraviolet. In the second part of the thesis, we focus on the analysis of optical and near NIR observations of over 1000 galaxies in 9 clusters, selected from…
Subjects/Keywords: Γαλαξίες; Μορφολογία γαλαξιών; Δομή γαλαξιών; Εξέλιξη γαλαξιών; Σμήνη γαλαξιών; Galaxies; Galaxy morphology; Galaxy structure; Galaxy evolution; Galaxy interactions; Galaxy clusters
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APA ·
Chicago ·
MLA ·
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Export
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Manager
APA (6th Edition):
Psychogyios, A. (2018). Galaxy morphology in different environments. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/44308
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Psychogyios, Alexandros. “Galaxy morphology in different environments.” 2018. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed January 22, 2021.
http://hdl.handle.net/10442/hedi/44308.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Psychogyios, Alexandros. “Galaxy morphology in different environments.” 2018. Web. 22 Jan 2021.
Vancouver:
Psychogyios A. Galaxy morphology in different environments. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2018. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/10442/hedi/44308.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Psychogyios A. Galaxy morphology in different environments. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2018. Available from: http://hdl.handle.net/10442/hedi/44308
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Queens University
30.
Wagner, Cory.
The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
.
Degree: Physics, Engineering Physics and Astronomy, 2014, Queens University
URL: http://hdl.handle.net/1974/12539
► In this thesis, we explore 7.5 billion years of evolution in cluster galaxy star formation activity using a sample of 11 high-redshift (1 < z…
(more)
▼ In this thesis, we explore 7.5 billion years of evolution in cluster galaxy star formation activity using a sample of 11 high-redshift (1 < z < 1.5) clusters from the IRAC Shallow Cluster Survey, and 25 low-redshift (0.15 < z < 1) clusters from The Cluster Lensing And Supernova survey with Hubble. We compare cluster galaxy star formation to that of the field over 0.15 < z < 1.5 using ~8000 galaxies from the UltraVISTA survey. Mid-infrared star formation rates are measured using Spitzer 24 μm data for isolated high-redshift galaxies. We calculate rest-frame ultraviolet star formation rates for low-redshift cluster members using Hubble Space Telescope observations. Using publically available mid-infrared and ultraviolet data for our field sample, we empirically derive scaling relations to adjust low-redshift cluster galaxy ultraviolet star formation rates to mid-infrared levels. We classify cluster galaxy morphology by visual inspection, and use quantitatively measured morphologies for field galaxies. Cluster late-type galaxies at z > 1 show enhanced star formation activity relative to the field, and account for nearly 90% of the overall star formation activity in high-redshift clusters. While high-redshift early-type galaxies are substantially quenched relative to cluster late-types, they still contribute ~13% of the total cluster star formation activity. With early-type fractions increasing from 34 to 56% from z ~ 1.5 → 1.16, we find that new cluster early-type galaxies are likely being formed around z ~ 1.4. The fraction of early-type galaxies that are star-forming drops from 29 to 11% over this period, yet their specific star formation rates are roughly constant. These factors suggest that the events that created these new galaxies, possibly mergers, were both recent and gas-rich. With typical coverages of 50% of z < 1 cluster virial radii, we can only probe the cores of low-redshift clusters. We find that in this regime, the star formation activity of cluster galaxies is quenched relative to the field. We compare the mean star formation rate of cluster galaxies to the results of Alberts et al. (2014), who fit the mean star formation rate evolution over 0.3 < z < 1.5, and measured star formation rates by stacking 250 μm Herschel images. We find excellent agreement between the Herschel-based fit and both our Spitzer-derived and ultraviolet → infrared star formation rates.
Subjects/Keywords: Galaxies
;
Astronomy
;
Elliptical galaxies
;
High-redshift
;
Astrophysics
;
Galaxy evolution
;
Galaxy clusters
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APA ·
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MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Wagner, C. (2014). The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
. (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/12539
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wagner, Cory. “The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
.” 2014. Thesis, Queens University. Accessed January 22, 2021.
http://hdl.handle.net/1974/12539.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wagner, Cory. “The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
.” 2014. Web. 22 Jan 2021.
Vancouver:
Wagner C. The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
. [Internet] [Thesis]. Queens University; 2014. [cited 2021 Jan 22].
Available from: http://hdl.handle.net/1974/12539.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wagner C. The Evolution of Star Formation Activity in Cluster Galaxies Over 0.15 < z < 1.5
. [Thesis]. Queens University; 2014. Available from: http://hdl.handle.net/1974/12539
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
◁ [1] [2] [3] [4] [5] [6] [7] [8] ▶
. 
Open Access Theses and Dissertations
