New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies

Galaxies in transition from star-forming to quiescence are a natural laboratory for exploring the processes responsible for this evolution. Using a sample of post-starburst galaxies identified to have recently experienced a recent burst of star formation that has now ended, I explore both the fate o...

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Main Author: French, Katheryn Decker
Other Authors: Zabludoff, Ann
Language:en_US
Published: The University of Arizona. 2017
Online Access:http://hdl.handle.net/10150/625618
http://arizona.openrepository.com/arizona/handle/10150/625618
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spelling ndltd-arizona.edu-oai-arizona.openrepository.com-10150-6256182017-09-27T03:00:29Z New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies French, Katheryn Decker French, Katheryn Decker Zabludoff, Ann Zabludoff, Ann Shirley, Yancy Marrone, Daniel Stark, Daniel Juneau, Stephanie Galaxies in transition from star-forming to quiescence are a natural laboratory for exploring the processes responsible for this evolution. Using a sample of post-starburst galaxies identified to have recently experienced a recent burst of star formation that has now ended, I explore both the fate of the molecular gas that drives star formation and the increased rate of stars disrupted by the central supermassive black hole. Chapter 1 provides an introduction to galaxy evolution through the post-starburst phase and to tidal disruption events, which surprisingly favor post-starburst galaxy hosts. In Chapter 2, I present a survey of the molecular gas properties of 32 post-starburst galaxies traced by CO (1--0) and CO (2--1). In order to accurately put galaxies on an evolutionary sequence, we must select likely progenitors and descendants. We do this by identifying galaxies with similar starburst properties, such as the amount of mass produced in the burst and the burst duration. In Chapter 3, I describe a method to determine the starburst properties and the time elapsed since the starburst ended, and discuss trends in the molecular gas properties of these galaxies with time. In Chapter 4, I present the results of followup observations with ALMA of HCN (1--0) and HCO+ (1--0) in two post-starburst galaxies. CO (1--0) is detected in over half (17/32) the post-starburst sample and the molecular gas mass traced by CO declines on ~100 Myr timescales after the starburst has ended. HCN (1--0) is not detected in either galaxy targeted, indicating the post-starbursts are now quiescent because of a lack of the denser molecular gas traced by HCN. In Chapter 5 I quantify the increase in TDE rate in quiescent galaxies with strong Balmer absorption to be 30-200x higher than in normal galaxies. Using the stellar population fitting method from Chapter 3, I examine possible reasons for the increased TDE rate in post-starburst galaxies in Chapter 6. The TDE rate could be boosted due to a binary supermassive black hole coalescing after a major merger or an increased density of stars or gas remaining near the nucleus after the starburst has ended. In Chapter 7, I present a summary of the findings of this dissertation and an outlook for future work. 2017 text Electronic Dissertation http://hdl.handle.net/10150/625618 http://arizona.openrepository.com/arizona/handle/10150/625618 en_US Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. The University of Arizona.
collection NDLTD
language en_US
sources NDLTD
description Galaxies in transition from star-forming to quiescence are a natural laboratory for exploring the processes responsible for this evolution. Using a sample of post-starburst galaxies identified to have recently experienced a recent burst of star formation that has now ended, I explore both the fate of the molecular gas that drives star formation and the increased rate of stars disrupted by the central supermassive black hole. Chapter 1 provides an introduction to galaxy evolution through the post-starburst phase and to tidal disruption events, which surprisingly favor post-starburst galaxy hosts. In Chapter 2, I present a survey of the molecular gas properties of 32 post-starburst galaxies traced by CO (1--0) and CO (2--1). In order to accurately put galaxies on an evolutionary sequence, we must select likely progenitors and descendants. We do this by identifying galaxies with similar starburst properties, such as the amount of mass produced in the burst and the burst duration. In Chapter 3, I describe a method to determine the starburst properties and the time elapsed since the starburst ended, and discuss trends in the molecular gas properties of these galaxies with time. In Chapter 4, I present the results of followup observations with ALMA of HCN (1--0) and HCO+ (1--0) in two post-starburst galaxies. CO (1--0) is detected in over half (17/32) the post-starburst sample and the molecular gas mass traced by CO declines on ~100 Myr timescales after the starburst has ended. HCN (1--0) is not detected in either galaxy targeted, indicating the post-starbursts are now quiescent because of a lack of the denser molecular gas traced by HCN. In Chapter 5 I quantify the increase in TDE rate in quiescent galaxies with strong Balmer absorption to be 30-200x higher than in normal galaxies. Using the stellar population fitting method from Chapter 3, I examine possible reasons for the increased TDE rate in post-starburst galaxies in Chapter 6. The TDE rate could be boosted due to a binary supermassive black hole coalescing after a major merger or an increased density of stars or gas remaining near the nucleus after the starburst has ended. In Chapter 7, I present a summary of the findings of this dissertation and an outlook for future work.
author2 Zabludoff, Ann
author_facet Zabludoff, Ann
French, Katheryn Decker
French, Katheryn Decker
author French, Katheryn Decker
French, Katheryn Decker
spellingShingle French, Katheryn Decker
French, Katheryn Decker
New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
author_sort French, Katheryn Decker
title New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
title_short New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
title_full New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
title_fullStr New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
title_full_unstemmed New Methods for Tracking Galaxy and Black Hole Evolution Using Post-Starburst Galaxies
title_sort new methods for tracking galaxy and black hole evolution using post-starburst galaxies
publisher The University of Arizona.
publishDate 2017
url http://hdl.handle.net/10150/625618
http://arizona.openrepository.com/arizona/handle/10150/625618
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