The Herschel Multi-Tiered Extragalactic Survey: Source Extraction and Cross-Identifications in Confusion-Dominated SPIRE Images
Abstract
We present the cross-identification and source photometry techniques used to process Herschel SPIRE imaging taken as part of the Herschel Multi-Tiered Extragalactic Survey (HerMES). Cross-identifications are performed in map-space so as to minimise source blending effects. We make use of a combination of linear inversion and model selection techniques to produce reliable cross-identification catalogues based on Spitzer MIPS 24 micron source positions. Testing on simulations and real Herschel observations show that this approach gives robust results for even the faintest sources S250~10 mJy. We apply our new technique to HerMES SPIRE observations taken as part of the science demostration phase of Herschel. For our real SPIRE observations we show that, for bright unconfused sources, our flux density estimates are in good agreement with those produced via more traditional point source detection methods (SussExtractor; Savage & Oliver et al. 2006) by Smith et al. 2010. When compared to the measured number density of sources in the SPIRE bands, we show that our method allows the recovery of a larger fraction of faint sources than these traditional methods. However this completeness is heavily dependant on the relative depth of the existing 24 micron catalogues and SPIRE imaging. Using our deepest multi-wavelength dataset in GOODS-N, we estimate that the use of shallow 24 micron in our other fields introduces an incompleteness at faint levels of between 20-40 per cent at 250 micron.
Keywords
Cite
@article{arxiv.1009.1658,
title = {The Herschel Multi-Tiered Extragalactic Survey: Source Extraction and Cross-Identifications in Confusion-Dominated SPIRE Images},
author = {I. G. Roseboom and S. J. Oliver and M. Kunz and B. Altieri and A. Amblard and V. Arumugam and R. Auld and H. Aussel and T. Babbedge and M. Béthermin and A. Blain and J. Bock and A. Boselli and D. Brisbin and V. Buat and D. Burgarella and N. Castro-Rodríguez and A. Cava and P. Chanial and E. Chapin and D. L. Clements and A. Conley and L. Conversi and A. Cooray and C. D. Dowell and E. Dwek and S. Dye and S. Eales and D. Elbaz and D. Farrah and M. Fox and A. Franceschini and W. Gear and J. Glenn and E. A. González Solares and M. Griffin and M. Halpern and M. Harwit and E. Hatziminaoglou and J. Huang and E. Ibar and K. Isaak and R. J. Ivison and G. Lagache and L. Levenson and N. Lu and S. Madden and B. Maffei and G. Mainetti and L. Marchetti and G. Marsden and A. M. J. Mortier and H. T. Nguyen and B. O'Halloran and A. Omont and M. J. Page and P. Panuzzo and A. Papageorgiou and H. Patel and C. P. Pearson and I. Pérez-Fournon and M. Pohlen and J. I. Rawlings and G. Raymond and D. Rigopoulou and D. Rizzo and M. Rowan-Robinson and M. Sánchez Portal and B. Schulz and Douglas Scott and N. Seymour and D. L. Shupe and A. J. Smith and J. A. Stevens and M. Symeonidis and M. Trichas and K. E. Tugwell and M. Vaccari and I. Valtchanov and J. D. Vieira and L. Vigroux and L. Wang and R. Ward and G. Wright and C. K. Xu and M. Zemcov},
journal= {arXiv preprint arXiv:1009.1658},
year = {2015}
}
Comments
Accepted for publication in MNRAS, 19 pages, 11 figures