Derek Hand is a senior at UH Hilo and is majoring in Astrophysics. He originally comes from Bemidji, Minnesota, but has been living on the Big Island for the last 2 years. He has interests ranging from outdoors sports to observational astronomy and computational physics. Derek hopes to attend graduate school at the Universitat de Barcelona or the University of Minnesota to study galaxy evolution or particle physics. 

Home Island: Big Island
Institute when accepted: University of Hawai‘i at Hilo

Gas in Luminous Infrared Galaxies

Project Site: Gemini North Observatory
Mentor: Andreea Petric

Project Abstract

Luminous Infrared Galaxies (LIRGs) bridge the luminosity gap between star-forming galaxies and quasars, and so they may provide the link between the extreme objects we see at high redshift and typical nearby systems.  Furthermore, LIRGs span the full range of galaxy interactions from non-merging spirals to late-stage mergers, so they are excellent laboratories in which to study the effect of mergers on the interstellar medium in galaxies as a function of interaction.  The goal of this project is to assess if and how the molecular-gas properties of LIRGs change as a function of (1) merger stage, (2) IR luminosity and (3) AGN contribution to the IR emission.  Our sample is drawn from the Great Observatories All-Sky LIRG Survey (GOALS) sources.  We assess the molecular gas properties by combining published observations of the cold gas that we obtained from searching the Nasa/IPAC Extragalatic Database (NED) with Spitzer and Herschel measurements of the warm H2 and CO gas.  The merger stages were estimated by comparing the available MIR and NIR maps from Spitzer and Hubble with simulations of gas-rich major mergers.  The IR luminosities were derived from the 8-1000 micrometer photometric data.  The AGN contribution to the IR is estimated from the [O IV / Ne II] line ratios, which are based on empirical measurements of high to low ionization flux ratios in pure AGN and star-forming galaxies.