The identification of dust heating mechanisms in nearby galaxies using Herschel 160/250 and 250/350μm surface brightness ratios
Abstract
We examined variations in the 160/250 and 250/350 μm surface brightness ratios within 24 nearby (<30 Mpc) face-on spiral galaxies observed with the Herschel Space Observatory to identify the heating mechanisms for dust emitting at these wavelengths. The analysis consisted of both qualitative and quantitative comparisons of the 160/250 and 250/350 μm ratios to Hα and 24 μm emission, which trace the light from star-forming regions, and 3.6 μm emission, which traces the light from the older stellar populations of the galaxies. We find broad variations in the heating mechanisms for the dust. In one subset of galaxies, we found evidence that emission at ≤160 μm (and in rare cases potentially at ≤350 μm) originates from dust heated by star-forming regions. In another subset, we found that the emission at ≥250 μm (and sometimes at ≥160 μm) originates from dust heated by the older stellar population. In the rest of the sample, either the results are indeterminate or both of these stellar populations may contribute equally to the global dust heating. The observed variations in dust heating mechanisms do not necessarily match what has been predicted by dust emission and radiative transfer models, which could lead to overestimated dust temperatures, underestimated dust masses, false detections of variability in dust emissivity, and inaccurate star formation rate measurements.
Additional Information
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2014 September 4. Received 2014 September 3; in original form 2014 July 25. First published online February 2, 2015. We thank the reviewer for the helpful comments on this paper. GJB is funded by the STFC. IDL is a postdoctoral researcher of the FWO-Vlaanderen (Belgium). The Herschel spacecraft was designed, built, tested, and launched under a contract to ESA managed by the Herschel/Planck Project team by an industrial consortium under the overall responsibility of the prime contractor Thales Alenia Space (Cannes), and including Astrium (Friedrichshafen) responsible for the payload module and for system testing at spacecraft level, Thales Alenia Space (Turin) responsible for the service module, and Astrium (Toulouse) responsible for the telescope, with in excess of a hundred subcontractors. SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA). HIPE is a joint development (are joint developments) by the Herschel Science Ground Segment Consortium, consisting of ESA, the NASA Herschel Science Center, and the HIFI, PACS and SPIRE consortia. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.Attached Files
Published - MNRAS-2015-Bendo-135-67.pdf
Submitted - 1409.1815v1.pdf
Supplemental Material - bendogj_fig01.pdf
Supplemental Material - bendogj_fig07.pdf
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Additional details
- Eprint ID
- 56362
- Resolver ID
- CaltechAUTHORS:20150406-073106027
- Science and Technology Facilities Council (STFC)
- Canadian Space Agency (CSA)
- National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
- Commissariat à l'Energie Atomique (CEA)
- Centre National d'Études Spatiales (CNES)
- Centre National de la Recherche Scientifique (CNRS)
- Agenzia Spaziale Italiana (ASI)
- Ministerio de Ciencia e Innovación (MCINN)
- Swedish National Space Board (SNSB)
- United Kingdom Space Agency (UKSA)
- NASA
- Created
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2015-04-06Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)