| Description |
Luminous Infrared Galaxies (LIRGs; having LIR > 10^11 Lsun), emit asignificant fraction of their bolometric luminosity in thefar-infrared and are a mixture of single galaxies, interacting systemsand advanced mergers, exhibiting enhanced star formation rates and ahigher fraction of Active Galactic Nuclei (AGN) compared to lessluminous galaxies. With the Great Observatories All-sky LIRG Survey(GOALS), we are measuring the properties of a large, complete sampleof 202 low-redshift LIRGs across the electromagnetic spectrum usingSpitzer, HST, Chandra, GALEX and a number of ground-basedobservatories. Here, we propose to measure the CII 157.7, OI 63.2and OIII 88 micron far-infrared emission lines and the OH 79 micronabsorption feature in the GOALS sample with the PACS on the HerschelSpace Observatory. We will target 154 LIRGs in CII, OI, and OHand 66 LIRGs in OIII for a total requested time of 166.9 hrs. ThePACS data will allow us to penetrate the dust and measure the spatialdistribution, dynamics and overall energy budgets in a large sample ofLIRGs at low redshift for the first time. In addition to providing ameasure of the physical conditions in the warm, neutral and ionizedinterstellar medium (ISM) in LIRGs, these data will allow us toestablish a precise, quantitative FIR-based measure of the starformation rate that can be used across a wide range of galacticluminosities, even in the presence of powerful AGN. GOALS, with itsrich ancillary dataset that covers X-ray through millimeterwavelengths, provides the perfect sample for this study. Our proposedobservations will greatly extend the work started with ISO, and laythe foundation for high-redshift galactic studies with futurefacilities (e.g., ALMA) that will target the FIR and sub-mm spectralregions over the next decade. |
