Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-06-12
Astronomy and Astrophysics
Astrophysics
9 pages, 4 Postscript figures, uses mn2e.cls. To appear in the Monthly Notices of Royal Astro. Society
Scientific paper
10.1111/j.1365-2966.2008.13565.x
High-redshift submillimetre-bright galaxies identified by blank field surveys at millimetre and submillimetre wavelengths appear in the region of the IRAC colour-colour diagrams previously identified as the domain of luminous active galactic nuclei (AGNs). Our analysis using a set of empirical and theoretical dusty starburst spectral energy distribution (SED) models shows that power-law continuum sources associated with hot dust heated by young (<100 Myr old), extreme starbursts at z>2 also occupy the same general area as AGNs in the IRAC colour-colour plots. A detailed comparison of the IRAC colours and SEDs demonstrates that the two populations are distinct from each other, with submillimetre-bright galaxies having a systematically flatter IRAC spectrum (>1 mag bluer in the observed [4.5]-[8.0] colour). Only about 20% of the objects overlap in the colour-colour plots, and this low fraction suggests that submillimetre galaxies powered by a dust-obscured AGN are not common. The red IR colours of the submillimetre galaxies are distinct from those of the ubiquitous foreground IRAC sources, and we propose a set of IR colour selection criteria for identifying SMG counterparts that can be used even in the absence of radio or Spitzer MIPS 24 micron data.
Aretxaga Itziar
Ashby Matt L. N.
Austermann Jacqueline
Fazio Giacomo
Giavalisco Mauro
No associations
LandOfFree
Spitzer IRAC Infrared Colours of Submillimetre-bright Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spitzer IRAC Infrared Colours of Submillimetre-bright Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spitzer IRAC Infrared Colours of Submillimetre-bright Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-122725