| Description |
Recent results based on far-infrared (IR) data obtained with Herschel strongly suggest the existence of two modes of star formation that apply to low and high-redshift galaxies: a quiescent mode for disks (or main-sequence galaxies) and a starburst mode probably associated with more efficient nuclear, compact star formation. This dichotomy implies that the properties of the inter stellar medium (ISM) in these two types of systems must be substantially different. We have used the mid- to far-IR colors of galaxies as a proxy for their compactness to select a sample of local, compact luminous IR galaxies ((U)LIRGs; LIR >= 10^11 Lsun) from the IRAS 12-micron sample. Our sample of 73 compact (U)LIRGs includes both Seyfert galaxies as well as purely star-forming systems, and therefore is not biased towards active galaxies only. We will observe the key far-IR CII158, OI63, and OIII88 micron emission lines with Herschel/PACS and use models of photo-dissociation regions (PDRs), shocks, X-ray dissociation regions (XDRs), and dusty AGNs to derive the main physical parameters of the ISM in this important class of systems, which are not being targeted by any Herschel project. Our proposed galaxy sample bridges the gap between other studies focused on the analysis of local galaxies with a range of IR luminosities, mid- to far-IR colors, or more spatially extended IR emission, providing a wider view of the star formation and nuclear activity in local IR-bright galaxies in extreme environments, and thus adding a significant contribution to the Herschel legacy. The total time requested for achieving this goal is 89.8 hours. |
| Keywords |
Herschel Space Observatory data, ESA Herschel mission dataset, far-infrared astronomy observations, submillimeter astronomy data, infrared space telescope observations, PACS photometer data, PACS spectrometer data, SPIRE photometer data, SPIRE Fourier transform spectrometer data, HIFI heterodyne spectroscopy data, far-infrared spectroscopy dataset, submillimeter spectral line observations, cold universe observations dataset, star formation infrared data, molecular cloud far-infrared observations, interstellar medium spectroscopy data, protoplanetary disk infrared observations, galaxy evolution far-infrared data, dust emission submillimeter observations, cosmic infrared background measurements, extragalactic infrared survey data, calibrated level 2 data products, FITS files astronomy, spectral cubes far-infrared, flux-calibrated maps, continuum photometry data, spectral energy distribution measurements, ESA Herschel Science Archive data |
