ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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Description
In the past three decades with the deployment of space-based from x-rays to infrared telescopes and operation of 8-10 m class ground based telescopes, a hand-full of regions of the sky have emerged that probe the distant universe over relatively wide fields with the aim of understanding the assembly of apparently faint galaxies. To explore this new frontier, observations were made with the Large Binocular Cameras (LBCs) on the Large Binocular Telescope (LBT) of a well-studied deep field, GOODS-North, which has been observed by a wide range of telescopes from the radio to x-ray. I present a study of the trade-off between depth and resolution using a large number of LBT/LBC U-band and R-band imaging observations in the GOODS-N field. Having acquired over 30 hours of data (315 images with 5-6 minute exposures) for U-band and 27 hours for R-band (828 images with 2 minute exposures), multiple mosaics were generated, starting with images taken under the best atmospheric conditions (FWHM <0.8"). For subsequent mosaics, data with coarser seeing values were added in until the final, deepest mosaic included all images with FWHM <1.8". For each mosaic, object catalogs were made to compare the optimal-resolution, yet shallower image to the low-resolution but deeper image. For the brightest galaxies within the GOODS-N field, structure and clumpy features within the galaxies are more prominent in the optimal-resolution image compared to the deeper mosaics. I conclude that for studies of brighter galaxies and features within them, the optimal-resolution image should be used. However, to fully explore and understand the faintest objects, the deeper imaging with lower resolution are also required. For the 220 and 360 brightest galaxies in the U-band and R-band images respectively, there is only a marginal difference between the optimal-resolution and lower-resolution light-profiles and their integrated total fluxes. This helps constrain how much flux can be missed in galaxy outskirts, which is important for studies of Extragalactic Background Light. Finally, I also comment on a collection of galaxies in the field with tidal tails and streams, diffuse plumes, and bridges.
ContributorsAshcraft, Teresa Ann (Author) / Windhorst, Rogier A (Thesis advisor) / Borthakur, Sanchayeeta (Committee member) / Jansen, Rolf A (Committee member) / Scowen, Paul (Committee member) / Groppi, Chris (Committee member) / Arizona State University (Publisher)
Created2018
Description
Galaxy formation is a complex process with aspects that are still very uncertain or unknown. A mechanism that has been utilized in simulations to successfully resolve several of these outstanding issues is active galactic nucleus (AGN) feedback. Recent work has shown that a promising method for directly measuring this energy is by looking at small increases in the energy of cosmic microwave background (CMB) photons as they pass through ionized gas, known as the thermal Sunyaev-Zel’dovich (tSZ) effect.
In this work, I present stacked CMB measurements of a large number of elliptical galaxies never before measured using this method. I split the galaxies into two redshift groups, "low-z" for z=0.5-1.0 and “high-z” for z=1.0-1.5. I make two independent sets of CMB measurements using data from the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT), respectively, and I use data from the Planck telescope to account for contamination from dust emission. With SPT I find average thermal energies of 7.6(+3.0/−2.3) × 10^60 erg for 937 low-z galaxies, and 6.0(+7.7/−6.3) × 10^60 erg for 240 high-z galaxies. With ACT I find average thermal energies of 5.6(+5.9/−5.6) × 10^60 erg for 227 low-z galaxies, and 7.0(+4.7/−4.4) × 10^60 erg for 529 high-z galaxies.
I then attempt to further interpret the physical meaning of my observational results by incorporating two large-scale cosmological hydrodynamical simulations, one with (Horizon-AGN) and one without (Horizon-NoAGN) AGN feedback. I extract simulated tSZ measurements around a population of galaxies equivalent to those used in my observational work, with matching mass distributions, and compare the results. I find that the SPT measurements are consistent with Horizon-AGN, falling within 0.4σ at low-z and 0.5σ at high-z, while the ACT measurements are very different from Horizon-AGN, off by 6.9σ at low-z and 14.6σ at high-z. Additionally, the SPT measurements are loosely inconsistent with Horizon-NoAGN, off by 1.8σ at low-z but within 0.6σ at high-z, while the ACT measurements are loosely consistent with Horizon-NoAGN (at least much more so than with Horizon-AGN), falling within 0.8σ at low-z but off by 1.9σ at high-z.
In this work, I present stacked CMB measurements of a large number of elliptical galaxies never before measured using this method. I split the galaxies into two redshift groups, "low-z" for z=0.5-1.0 and “high-z” for z=1.0-1.5. I make two independent sets of CMB measurements using data from the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT), respectively, and I use data from the Planck telescope to account for contamination from dust emission. With SPT I find average thermal energies of 7.6(+3.0/−2.3) × 10^60 erg for 937 low-z galaxies, and 6.0(+7.7/−6.3) × 10^60 erg for 240 high-z galaxies. With ACT I find average thermal energies of 5.6(+5.9/−5.6) × 10^60 erg for 227 low-z galaxies, and 7.0(+4.7/−4.4) × 10^60 erg for 529 high-z galaxies.
I then attempt to further interpret the physical meaning of my observational results by incorporating two large-scale cosmological hydrodynamical simulations, one with (Horizon-AGN) and one without (Horizon-NoAGN) AGN feedback. I extract simulated tSZ measurements around a population of galaxies equivalent to those used in my observational work, with matching mass distributions, and compare the results. I find that the SPT measurements are consistent with Horizon-AGN, falling within 0.4σ at low-z and 0.5σ at high-z, while the ACT measurements are very different from Horizon-AGN, off by 6.9σ at low-z and 14.6σ at high-z. Additionally, the SPT measurements are loosely inconsistent with Horizon-NoAGN, off by 1.8σ at low-z but within 0.6σ at high-z, while the ACT measurements are loosely consistent with Horizon-NoAGN (at least much more so than with Horizon-AGN), falling within 0.8σ at low-z but off by 1.9σ at high-z.
ContributorsSpacek, Alexander Edward (Author) / Scannapieco, Evan (Thesis advisor) / Bowman, Judd (Committee member) / Butler, Nat (Committee member) / Groppi, Chris (Committee member) / Young, Patrick (Committee member) / Arizona State University (Publisher)
Created2017