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Full-Text Articles in Astrophysics and Astronomy
Dissecting The Most Extreme Starburst Events In The Universe With Gravitational Lensing, Patrick S. Kamienski
Dissecting The Most Extreme Starburst Events In The Universe With Gravitational Lensing, Patrick S. Kamienski
Doctoral Dissertations
Three billions years after the Big Bang, the rate at which galaxies in the Universe were forming stars was at its peak. Colloquially known as Cosmic Noon, this epoch (redshift z ~ 2) is crucial to our understanding of how galaxies evolve with time. Dusty star-forming galaxies (DSFGs) offer important clues to such fueling and quenching of star formation. With extreme infrared luminosities (1012 − 1014 solar luminosities), their inferred star formation rates are 100−10000 solar masses per year. Yet, the physical mechanisms by which they fuel this short-lived maximal starburst phase remain poorly understood. With this dissertation, …
Probing Galaxy Evolution Through Deep Radio Continuum Observations, Hansung Gim
Probing Galaxy Evolution Through Deep Radio Continuum Observations, Hansung Gim
Doctoral Dissertations
One of the most important questions in modern astrophysics is how galaxies form and evolve. There are numerous processes involved in galaxy evolution, but the stellar mass buildup and supermassive black hole growth are two main drivers in galaxy evolution. Those activities are heavily obscured by dust, so we need another tracer without dust attenuation: low-frequency radio continuum observation. We understand the galaxy evolution through the deep radio continuum observations on the Great Observatories Origins Deep Survey (GOODS)-North, -South, and the COSMOS HI Large Extragalactic Survey (CHILES) fields. Exploiting the multi-wavelength dataset, we define the radio populations such as star-formation …
Environmentally Driven Galaxy Evolution And Quenching: Insights From The Low-Redshift Circumgalactic Medium, Joseph Burchett
Environmentally Driven Galaxy Evolution And Quenching: Insights From The Low-Redshift Circumgalactic Medium, Joseph Burchett
Doctoral Dissertations
The gaseous halos of galaxies -- the circumgalactic medium (CGM) -- serve as interfaces playing host to the fueling and feedback processes that sustain and regulate star formation. Furthermore, interactions between galaxies one with another and with larger scale structure, such as galaxy cluster halos, must necessarily act through the CGM. This dissertation examines the CGM as traced by H I, C IV, and O VI absorption lines across wide range of halo environments, from isolated dwarf galaxies with M* < 108 Msun to galaxy clusters with Mhalo > 1014 Msun. By first conducting a blind …
Ultraviolet To Infrared Star Formation Rate Tracers: Characterizing Dust Attenuation And Emission, Andrew Battisti
Ultraviolet To Infrared Star Formation Rate Tracers: Characterizing Dust Attenuation And Emission, Andrew Battisti
Doctoral Dissertations
Star formation rates (SFRs) are among the fundamental properties used to characterize galaxies during their evolution across cosmic times. In the first part of this dissertation, we calibrate continuous, monochromatic SFR indicators over the mid-infrared wavelength range of 6-70 micron. We use a sample of 58 local star-forming galaxies for which there is a rich suite of multi-wavelength photometry and spectroscopy from the ultraviolet through far-infrared. Our results indicate that our mid-infrared SFR indicators are applicable to galaxies over a large range of distances, proving their robustness. We have made the calibrations and diagnostics publicly available to achieve the broadest …
The Cosmic Web, And The Role Of Environment In Galaxy Evolution, Ryan Cybulski
The Cosmic Web, And The Role Of Environment In Galaxy Evolution, Ryan Cybulski
Doctoral Dissertations
The Universe, on extra-galactic scales, is composed of a vast network of structures dubbed the “cosmic web”. One of the most fundamental discoveries about the evolution of galaxies is that their properties have a dependence on their location relative to this cosmic web (i.e., their environment). However, detailed studies of the environmental dependence on galaxy evolution have been extremely challenging due to the inherent complexity of the structures on the largest scales, a plethora of techniques being used to try to map the cosmic web, and other confounding factors, such as the masses of galaxies, that also affect their evolution. …
The Effect Of A Growing Black Hole On The Infrared Emission Of Dusty Galaxies In The Distant Universe, Allison Kirkpatrick
The Effect Of A Growing Black Hole On The Infrared Emission Of Dusty Galaxies In The Distant Universe, Allison Kirkpatrick
Doctoral Dissertations
The buildup of stellar and black hole mass peaked during z=1-3. Infrared (IR) luminous galaxies, which are massive and heavily dust obscured (LIR > 1011 Lsun), dominate the stellar growth during this era, and many are harboring a hidden active galactic nucleus (AGN). We have quantified the contribution of AGN heating to the infrared emission of a large sample of dusty, luminous galaxies from z=0.5-4 using Spitzer mid-IR spectroscopy, available for every source. We classify sources as star forming galaxies, AGN, or composites based on the presence of mid-IR continuum emission due to a dusty …
On The Formation And Evolution Of Early-Type Galaxies, Christina Williams
On The Formation And Evolution Of Early-Type Galaxies, Christina Williams
Doctoral Dissertations
Galaxies in the local Universe are characterized by blue, star-forming disk galaxies, and red, massive early-type galaxies (ETGs) whose star-formation has been quenched early in the Universe's history. The ETGs are relics of the evolutionary processes that transform galaxies over cosmic time, but currently we still lack a comprehensive understanding of their evolution. An important link in the evolution of ETGs is that the first quenched galaxies (z~2) are both the most massive, and most compact, suggesting a physical connection between high stellar density and efficient, rapid cessation of star-formation. In this dissertation, I seek insight into the formation and …