Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Arts and Sciences


Physics and Astronomy

First Advisor

Dr. Renbin Yan

Second Advisor

Dr. Ronald Wilhelm


In this dissertation, we explore the spatial distribution of quiescent regions within galaxies using data from the Sloan Digital Sky Survey IV Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV MaNGA). Our analysis focuses on a radial range spanning from 0.3 R e to 1.2 R e and involves the development of innovative data selection and processing methods. Through this investigation, we identify two prominent types of transition galaxies: central-star-forming galaxies (C-SF galaxies) and central-quiescent galaxies (C-Q galaxies). Notably, we observe a correlation between galaxy mass and the predominant type of transition, with more massive galaxies tending to be C-Q galaxies and less massive galaxies leaning towards C- SF galaxies. To explain the formation of C-Q galaxies, we propose a duty cycle hypothesis, suggesting intermittent quenching processes. Additionally, we speculate that the rejuvenation of quiescent galaxies could be responsible for the presence of C-SF galaxies. Moving beyond the study of transition galaxies, we also examine the connection between active galactic nuclei (AGN) activity and star formation. Our findings reveal that AGN activities are associated with both the enhancement and cessation of star formation, depending on the star formation status in the outskirts of the galaxy. We present a hypothesis to explain this observation, shedding light on the intricate interplay between AGN and star formation in galaxy evolution. Through our comprehensive analysis, this dissertation expands our understanding of the spatial progression of quenching mechanisms, the distinct roles of transition galaxies, and the complex relationship between AGN and star formation.

Digital Object Identifier (DOI)

Funding Information

We acknowledge support by NSF. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS web site is SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration including the Brazilian Participation Group, the Carnegie Institution for Science, Carnegie Mellon University, the Chilean Participation Group, the French Participation Group, Harvard-Smithsonian Center for Astrophysics, Instituto de Astrofı́sica de Canarias, The Johns Hopkins University, Kavli Institute for the Physics and Mathematics of the Universe (IPMU) / University of Tokyo, the Korean Participation Group, Lawrence Berkeley National Laboratory, Leibniz Institut für Astrophysik Potsdam (AIP), Max- Planck-Institut für Astronomie (MPIA Heidelberg), Max-Planck-Institut für Astro- physik (MPA Garching), Max-Planck-Institut für Extraterrestrische Physik (MPE), National Astronomical Observatories of China, New Mexico State University, New York University, University of Notre Dame, Observatório Nacional / MCTI, The Ohio State University, Pennsylvania State University, Shanghai Astronomical Obser- vatory, United Kingdom Participation Group, Universidad Nacional Autónoma de México, University of Arizona, University of Colorado Boulder, University of Oxford, University of Portsmouth, University of Utah, University of Virginia, University of Washington, University of Wisconsin, Vanderbilt University, and Yale University.