Dissecting the origin of the submillimetre emission in nearby galaxies with Herschel and LABOCA
Abstract
We model the infrared to submillimetre spectral energy distribution of 11 nearby galaxies of the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel sample using Spitzer and Herschel data and compare model extrapolations at 870 μm (using different fitting techniques) with Large APEX BOlometer CAmera (LABOCA) 870 μm observations. We investigate how the differences between predictions and observations vary with model assumptions or environment. At global scales, we find that modified blackbody models using realistic cold emissivity indices (β_c = 2 or 1.5) are able to reproduce the 870 μm observed emission within the uncertainties for most of the sample. Low values (β_c < 1.3) would be required in NGC 0337, NGC 1512 and NGC 7793. At local scales, we observe a systematic 870 μm excess when using β_c = 2.0. The β_c = 1.5 or the Draine & Li (2007) models can reconcile predictions with observations in part of the discs. Some of the remaining 'excesses' occur towards the centres and can be partly or fully accounted for by non-dust contributions such as CO(3–2) or, to a lesser extent, free–free or synchrotron emission. In three non-barred galaxies, the remaining excesses rather occur in the disc outskirts. This could be a sign of a flattening of the submm slope (and decrease of the effective emissivity index) with radius in these objects.
Additional Information
© 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. First published online: February 17, 2014. Accepted 2014 January 15. Received 2014 January 8; in original form 2013 October 31. We would like to thank the referee for a very constructive report that helped to improve the clarity/robustness of the results. The research of CDW is supported by grants from the Natural Sciences and Engineering Research Council of Canada. PACS has been developed by MPE (Germany); UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF-IFSI/OAA/OAP/OAT, LENS, SISSA (Italy); IAC (Spain). This development has been supported by BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy) and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including: Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy);IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCLMSSL, 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).Attached Files
Published - MNRAS-2014-Galametz-2542-70.pdf
Submitted - 1401.3693v1.pdf
Files
Name | Size | Download all |
---|---|---|
md5:6837fee276a00d62072429f4084797de
|
8.2 MB | Preview Download |
md5:f5efd02ae520dd59ca2a4855ff7f0fe3
|
11.1 MB | Preview Download |
Additional details
- Eprint ID
- 46000
- Resolver ID
- CaltechAUTHORS:20140530-103402531
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- MPE (Germany)
- UVIE (Austria)
- KU Leuven
- CSL (Belgium)
- IMEC (Belgium)
- Commissariat à l'Energie Atomique (CEA)
- LAM (France)
- Max Planck Institute for Astronomy (MPIA)
- INAF-IFSI/OAA/OAP/OAT (Italy)
- LENS (Italy)
- SISSA (Italy)
- IAC (Spain)
- Bundesministerium für Verkehr, Innovation und Technologie (BMVIT)
- ESA-PRODEX (Belgium)
- Centre National d'Études Spatiales (CNES)
- Deutsches Zentrum für Luft- und Raumfahrt (DLR)
- Agenzia Spaziale Italiana (ASI)
- CICYT/MCYT (Spain)
- Canadian Space Agency (CSA)
- National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
- Istituto Nazionale di Astrofisica (INAF)
- Centre National de la Recherche Scientifique (CNRS)
- Agenzia Spaziale Italiana (ASI)
- Ministerio de Ciencia e Innovación (MCINN)
- Swedish National Space Board (SNSB)
- Science and Technology Facilities Council (STFC)
- United Kingdom Space Agency (UKSA)
- NASA
- Created
-
2014-05-30Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)