CaltechAUTHORS
Published October 2013 | Version Published + Submitted
Journal Article Open

Mid- to far-infrared properties of star-forming galaxies and active galactic nuclei

Creators

  • 1. ROR icon University of Oxford
  • 2. ROR icon Rutherford Appleton Laboratory
  • 3. ROR icon Infrared Processing and Analysis Center
  • 4. ROR icon Virginia Tech
  • 5. ROR icon University of Sussex
  • 6. ROR icon Institute of Physics of Cantabria
  • 7. ROR icon California Institute of Technology
  • 8. ROR icon Jet Propulsion Lab
  • 9. ROR icon Aix-Marseille University
  • 10. ROR icon Dalhousie University
  • 11. ROR icon University of Crete
  • 12. ROR icon Foundation for Research and Technology Hellas
  • 13. ROR icon Paris Observatory
  • 14. ROR icon University of California, Berkeley
  • 15. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 16. ROR icon University of Wyoming
  • 17. ROR icon Institut de Recherche sur les Lois Fondamentales de l'Univers
  • 18. ROR icon European Southern Observatory
  • 19. ROR icon National Astronomical Observatories
  • 20. ROR icon University of Hawaii at Manoa
  • 21. ROR icon Canada–France–Hawaii Telescope
  • 22. ROR icon University College London
  • 23. ROR icon University of British Columbia
  • 24. ROR icon Nanjing University

Abstract

We study the mid- to far-IR properties of a 24 μm-selected flux-limited sample (S_(24)> 5 mJy) of 154 intermediate redshift (⟨ z ⟩ ~ 0.15), infrared luminous galaxies, drawn from the 5 Milli-Jansky Unbiased Spitzer Extragalactic Survey. By combining existing mid-IR spectroscopy and new Herschel SPIRE submm photometry from the Herschel Multi-tiered Extragalactic Survey, we derived robust total infrared luminosity (L_(IR)) and dust mass (M_(dust)) estimates and infered the relative contribution of the AGN to the infrared energy budget of the sources. We found that the total (8−1000 μm) infrared emission of galaxies with weak 6.2 μm PAH emission (EW_(6.2) ≤ 0.2 μm) is dominated by AGN activity, while for galaxies with EW_(6.2)> 0.2 μm more than 50% of the L_(IR) arises from star formation. We also found that for galaxies detected in the 250–500 μm Herschel bands an AGN has a statistically insignificant effect on the temperature of the cold dust and the far-IR colours of the host galaxy, which are primarily shaped by star formation activity. For star-forming galaxies we reveal an anti-correlation between the L_(IR)-to-rest-frame 8 μm luminosity ratio, IR8 ≡ L_(IR)/L_8  and the strength of PAH features. We found that this anti-correlation is primarily driven by variations in the PAHs emission, and not by variations in the 5−15 μm mid-IR continuum emission. Using the [Ne iii]/[Ne ii] line ratio as a tracer of the hardness of the radiation field, we confirm that galaxies with harder radiation fields tend to exhibit weaker PAH features, and found that they have higher IR8 values and higher dust-mass-weighted luminosities (L_(IR)/M_(dust)), the latter being a proxy for the dust temperature (T_d). We argue that these trends originate either from variations in the environment of the star-forming regions or are caused by variations in the age of the starburst. Finally, we provide scaling relations that will allow estimating L_(IR), based on single-band observations with the mid-infrared instrument, on board the upcoming James Webb Space Telescope.

Additional Information

© 2013 ESO. Article published by EDP Sciences. Received 8 July 2013. Accepted 23 August 2013. Published online 22 October 2013. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. GEM acknowledges support from the John Fell Oxford University Press (OUP) Research Fund and the University of Oxford. A.A.-H. acknowledges funding through the Universidad de Cantabria August G. Linares Programme. VC acknowledges partial support from the EU FP7 Grant PIRSES-GA-20120316788. This paper uses data from Herschel's photometer SPIRE. 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).

Attached Files

Published - aa22226-13.pdf

Submitted - 1309.3922v1.pdf

Files

1309.3922v1.pdf

Files (3.6 MB)

Name Size
md5:6d31a749d3a33f4ef3bc91214b37f95b
1.8 MB Preview Download
md5:bc018cbd3ebd15fb17bd274d7858a12f
1.8 MB Preview Download

Additional details

Identifiers

Eprint ID
43274
Resolver ID
CaltechAUTHORS:20140108-140820993

Related works

Describes
http://arxiv.org/abs/1309.3922 (URL)

Funding

John Fell Oxford University Press (OUP) Research Fund
University of Oxford
Universidad de Cantabria August G. Linares Programme
European Research Council (ERC)
PIRSES-GA-20120316788

Dates

Created
2014-01-08
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC) , Physics Department