| Description |
Luminous Infrared Galaxies (LIRGs; having LIR > 10^11 Lsun), emit a
significant fraction of their bolometric luminosity in the
far-infrared and are a mixture of single galaxies, interacting systems
and advanced mergers, exhibiting enhanced star formation rates and a
higher fraction of Active Galactic Nuclei (AGN) compared to less
luminous galaxies. With the Great Observatories All-sky LIRG Survey
(GOALS), we are measuring the properties of a large, complete sample
of 202 low-redshift LIRGs across the electromagnetic spectrum using
Spitzer, HST, Chandra, GALEX and a number of ground-based
observatories. Here, we propose to measure the CII 157.7, OI 63.2
and OIII 88 micron far-infrared emission lines and the OH 79 micron
absorption feature in the GOALS sample with the PACS on the Herschel
Space Observatory. We will target 154 LIRGs in CII, OI, and OH
and 66 LIRGs in OIII for a total requested time of 166.9 hrs. The
PACS data will allow us to penetrate the dust and measure the spatial
distribution, dynamics and overall energy budgets in a large sample of
LIRGs at low redshift for the first time. In addition to providing a
measure of the physical conditions in the warm, neutral and ionized
interstellar medium (ISM) in LIRGs, these data will allow us to
establish a precise, quantitative FIR-based measure of the star
formation rate that can be used across a wide range of galactic
luminosities, even in the presence of powerful AGN. GOALS, with its
rich ancillary dataset that covers X-ray through millimeter
wavelengths, provides the perfect sample for this study. Our proposed
observations will greatly extend the work started with ISO, and lay
the foundation for high-redshift galactic studies with future
facilities (e.g., ALMA) that will target the FIR and sub-mm spectral
regions over the next decade. |
