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Title: Investigating the presence of 500 μm submillimeter excess emission in local star forming galaxies

Submillimeter excess emission has been reported at 500 μm in a handful of local galaxies, and previous studies suggest that it could be correlated with metal abundance. We investigate the presence of an excess submillimeter emission at 500 μm for a sample of 20 galaxies from the Key Insights on Nearby Galaxies: a Far Infrared Survey with Herschel (KINGFISH) that span a range of morphologies and metallicities (12 + log (O/H) = 7.8-8.7). We probe the far-infrared (IR) emission using images from the Spitzer Space Telescope and Herschel Space Observatory in the wavelength range 24-500 μm. We model the far-IR peak of the dust emission with a two-temperature modified blackbody and measure excess of the 500 μm photometry relative to that predicted by our model. We compare the submillimeter excess, where present, with global galaxy metallicity and, where available, resolved metallicity measurements. We do not find any correlation between the 500 μm excess and metallicity. A few individual sources do show excess (10%-20%) at 500 μm; conversely, for other sources, the model overpredicts the measured 500 μm flux density by as much as 20%, creating a 500 μm 'deficit'. None of our sources has an excess larger than the calculatedmore » 1σ uncertainty, leading us to conclude that there is no substantial excess at submillimeter wavelengths at or shorter than 500 μm in our sample. Our results differ from previous studies detecting 500 μm excess in KINGFISH galaxies largely due to new, improved photometry used in this study.« less
Authors:
;  [1] ; ;  [2] ;  [3] ;  [4] ; ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. Department of Astronomy, University of Massachusetts, Amherst, MA 01002 (United States)
  2. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
  3. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
  4. Institut d'Astrophysique Spatiale, Université of Paris-Sud, F-91405 Orsay (France)
  5. Max-Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  6. Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States)
  7. Ritter Astrophysical Observatory, University of Toledo, Toledo, OH 43606 (United States)
  8. MMT Observatory, University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721 (United States)
  9. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)
  10. Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)
Publication Date:
OSTI Identifier:
22342015
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; COMPARATIVE EVALUATIONS; CORRELATIONS; DUSTS; EMISSION; FLUX DENSITY; IMAGES; INFRARED SURVEYS; METALLICITY; METALS; MILKY WAY; PHOTOMETRY; SPACE; STARS; TELESCOPES; WAVELENGTHS