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Paper: Extended Infrared Emission from (U)LIRGs
Volume: 446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective
Page: 49
Authors: Charmandaris, V.
Abstract: I discuss recent findings on the presence the extended emission of a volume limited (d < 82 Mpc) sample of luminous infrared galaxies(LIRGs) drawn from the Great Observatories All-sky LIRG Survey (GOALS) galaxy sample. Using Spitzer/IRS spectra to determine the fraction of emission arising from their extended component, we find the majority of LIRGs, at least ∼20% (and up to ∼80%) of their emission stems from an extended component. The IRS spectra also allow us to separate the different emission components (dust continuum and PAH feature emission, ionized and molecular gas) and calculate their corresponding spatial extent. We find that in several galaxies the PAH feature emission is more extended (up to 3 times) than that of the mid-infrared continuum. These results suggest that mid-infrared emission of LIRGs is not as compact as in their more luminous counterparts (ULIRGs) but instead it is distributed across their disks. Ongoing analysis of the extent of the different components will also enable us to ascertain whether the high redshift, higher luminosity submillimeter galaxies (SMGs), which also display fairly extended star formation, can be considered the scaled-up luminosity examples of local LIRGs, rather than ULIRGs.
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