The Evolution of and Starburst-AGN Connection in Luminous and Ultraluminous Infrared Galaxies and their Link to Globular Cluster Formation
type: CreativeWork
description: The evolutionary connection between nuclear starbursts and active galactic nuclei (AGN) in luminous infrared galaxies (LIRGs; 1011o<oLIRo< 1012 L) and ultraluminous infrared galaxies (ULIRGs; 1012 < LIR < 1013 L), which result from galaxy interactions and mergers and produce the bulk of their radiation as infrared (IR) emission, is not well understood. To this effort, I first spectroscopically examine U/LIRGs (1011 < LIR < 1013 L⊙) within the IRAS 2 Jansky Redshift Survey with 0.05 < z < 0.16. Using new spectrophotometric data, I classify the primary source of IR radiation as being a nuclear starburst or a type of AGN by using the Baldwin-Phillips-Terlevich (BPT) diagrams. I show that for the U/LIRGs in my sample the properties that describe their nuclear starbursts and AGN (e.g. star formation rate (SFR), L[O III], optical D parameter, D4000, and EW(Hδ)) are independent of one another, ensuring that no biases affect correlations between these properties and objects' locations on the BPT diagrams. I then derive evolutionary paths on the BPT diagram involving [N II]/Hα that are based on how these properties vary between two U/LIRGs positioned at the end-points. The paths involve U/LIRGs that decrease in SFR and increase in AGN activity. Paths with U/LIRGs that evolve into high luminosity AGN likely do so due to recent, strong starbursts. Second, to study how the properties of the IR power sources in U/LIRGs vary, I use a combination of photometric data points that I carefully measure (using photometry from SDSS, 2MASS, WISE, and Spitzer) and that I retrieve from catalogues (IRAS, AKARI, and ISO) to perform UV to FIR SED-fitting with CIGALE (Code Investigating GALaxy Emission) for 34 U/LIRGs from the IRAS 2 Jy Redshift Survey with 0.01 < z < 0.16. CIGALE allows for the estimation of numerous physical properties by means of a Bayesian-like analysis, but for this work I focus on derived outputs for the SFR, AGN contribution, D4000, stellar mass (Mstar), young stellar …
abstract: The evolutionary connection between nuclear starbursts and active galactic nuclei (AGN) in luminous infrared galaxies (LIRGs; 1011o<oLIRo< 1012 L) and ultraluminous infrared galaxies (ULIRGs; 1012 < LIR < 1013 L), which result from galaxy interactions and mergers and produce the bulk of their radiation as infrared (IR) emission, is not well understood. To this effort, I first spectroscopically examine U/LIRGs (1011 < LIR < 1013 L⊙) within the IRAS 2 Jansky Redshift Survey with 0.05 < z < 0.16. Using new spectrophotometric data, I classify the primary source of IR radiation as being a nuclear starburst or a type of AGN by using the Baldwin-Phillips-Terlevich (BPT) diagrams. I show that for the U/LIRGs in my sample the properties that describe their nuclear starbursts and AGN (e.g. star formation rate (SFR), L[O III], optical D parameter, D4000, and EW(Hδ)) are independent of one another, ensuring that no biases affect correlations between these properties and objects' locations on the BPT diagrams. I then derive evolutionary paths on the BPT diagram involving [N II]/Hα that are based on how these properties vary between two U/LIRGs positioned at the end-points. The paths involve U/LIRGs that decrease in SFR and increase in AGN activity. Paths with U/LIRGs that evolve into high luminosity AGN likely do so due to recent, strong starbursts. Second, to study how the properties of the IR power sources in U/LIRGs vary, I use a combination of photometric data points that I carefully measure (using photometry from SDSS, 2MASS, WISE, and Spitzer) and that I retrieve from catalogues (IRAS, AKARI, and ISO) to perform UV to FIR SED-fitting with CIGALE (Code Investigating GALaxy Emission) for 34 U/LIRGs from the IRAS 2 Jy Redshift Survey with 0.01 < z < 0.16. CIGALE allows for the estimation of numerous physical properties by means of a Bayesian-like analysis, but for this work I focus on derived outputs for the SFR, AGN contribution, D4000, stellar mass (Mstar), young stellar …
author: Fiorenza, Stephanie L.
keywords: Astrophysics and Astronomy, Physics, active galactic nuclei, galaxy evolution, infrared-bright galaxies, SED-fitting, starburst galaxies
date published: 2014-06-03T07:00:00Z
date modified: 2026-07-24T02:00:04Z
provider: City University of New York - Graduate Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The Graduate School and University Center of The City University of New York