Aims. The Herschel-ATLAS survey (H-ATLAS) will be the largest area survey to be undertaken by the Herschel Space Observatory. It will cover 550 sq. deg. of extragalactic sky at wavelengths of 100, 160, 250, 350 and 500 microns when completed, reaching flux limits (5 sigma) from 32 to 145mJy. We here present galaxy number counts obtained for SPIRE observations of the first ~14 sq. deg. observed at 250, 350 and 500 microns. Methods. Number counts are a fundamental tool in constraining models of galaxy evolution. We use source catalogs extracted from the H-ATLAS maps as the basis for such an analysis. Correction factors for completeness and flux boosting are derived by applying our extraction method to model catalogs and then applied to the raw observational counts. Results. We find a steep rise in the number counts at flux levels of 100-200mJy in all three SPIRE bands, consistent with results from BLAST. The counts are compared to a range of galaxy evolution models. None of the current models is an ideal fit to the data but all ascribe the steep rise to a population of luminous, rapidly evolving dusty galaxies at moderate to high redshift.
@article{arxiv.1005.2409,
title = {The Herschel-ATLAS: Extragalactic Number Counts from 250 to 500 Microns},
author = {D. L. Clements and E. Rigby and S. Maddox and L. Dunne and A. Mortier and C. Pearson and A. Amblard and R. Auld and M. Baes and D. Bonfield and D. Burgarella and S. Buttiglione and A. Cava and A. Cooray and A. Dariush and G. de Zotti and S. Dye and S. Eales and D. Frayer and J. Fritz and Jonathan P. Gardner and J. Gonzalez-Nuevo and D. Herranz and E. Ibar and R. Ivison and M. J. Jarvis and G. Lagache and L. Leeuw and M. Lopez-Caniego and M. Negrello and E. Pascale and M. Pohlen and G. Rodighiero and S. Samui and S. Serjeant and B. Sibthorpe and Douglas Scott and D. J. B. Smith and P. Temi and M. Thompson and I. Valtchanov and P. van der Werf and A. Verma},
journal= {arXiv preprint arXiv:1005.2409},
year = {2015}
}
Comments
Accepted for publication in Astronomy and Astrophysics