Star Formation and Nuclear Activity of Local Luminous Infrared Galaxies

Miguel Pereira Santaella

Departamento de Astrofísica

Año 2012

Luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies (ULIRGs) are galaxies with infrared (IR) luminosities (LIR) in the range between 1011 and 1012 L⊙, and >1012 L⊙, respectively. Intense star-formation bursts and/or an active galactic nucleus (AGN) are the power sources of these galaxies. These galaxies are unusual in the local universe, they represent less than 6 % of the IR emission in the local universe. Nevertheless, at high-redshift, z ∼ 1–2, (U)LIRGs have an important contribution to the star-formation rate (SFR) density of the Universe. Consequently, the study of local LIRGs is a fundamental piece to understanding their more distant counterparts.

This thesis is focused on the study of local LIRGs. For this purpose we defined a complete volume-limited sample of 53 local galaxies (0.009 < z < 0.017) with log(LIR/L⊙)>11.05. We analyzed mid-IR imaging and spectroscopic data obtained with Spitzer, and X-ray data from XMM-Newton and Chandra of these local LIRGs. The Spitzer spectroscopic data include observations from two GTO programs. Likewise the XMM-Newton X-ray data were obtained through two guest observer programs. In addition we used Spitzer, XMM-Newton, and Chandra archival data.

As a first step in our study, we characterized the mid-IR high-ionization emission lines produced by AGN and star-formation for a large sample of local galaxies, includ- ing LIRGs, observed with Spitzer (Chapter 3). In Chapter 4 we studied the spatially resolved mid-IR properties of a sample of 15 local LIRGs using Spitzer/IRS spectral mapping observations. Finally, in Chapter 5, we present the analysis of the X-ray prop- erties of a representative sample of 27 local LIRGs. […]

Datos de interés

Supervisores: Almudena Alonso Herrero (CAB), Rosa Domínguez Tenreiro
Universidad: Universidad Autónoma de Madrid. Departamento de Física Teórica; Centro de Astrobiología
Fecha de lectura: 03/02/2012