Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 2011 | Published
Journal Article Open

AzTEC millimetre survey of the COSMOS field – III. Source catalogue over 0.72 deg^2 and plausible boosting by large-scale structure


We present a 0.72 deg^2 contiguous 1.1-mm survey in the central area of the Cosmological Evolution Survey field carried out to a 1σ ≈ 1.26 mJy beam^(−1) depth with the AzTEC camera mounted on the 10-m Atacama Submillimeter Telescope Experiment. We have uncovered 189 candidate sources at a signal-to-noise ratio (S/N) ≥ 3.5, out of which 129, with S/N ≥ 4, can be considered to have little chance of being spurious (≲ 2 per cent). We present the number counts derived with this survey, which show a significant excess of sources when compared to the number counts derived from the ~0.5 deg^2 area sampled at similar depths in the Submillimetre Common-User Bolometer Array (SCUBA) HAlf Degree Extragalactic Survey (SHADES). They are, however, consistent with those derived from fields that were considered too small to characterize the overall blank-field population. We identify differences to be more significant in the S_(1.1mm) ≳ 5 mJy regime, and demonstrate that these excesses in number counts are related to the areas where galaxies at redshifts z ≲ 1.1 are more densely clustered. The positions of optical–infrared galaxies in the redshift interval 0.6 ≲ z ≲ 0.75 are the ones that show the strongest correlation with the positions of the 1.1-mm bright population (S_(1.1mm) ≳ 5 mJy), a result which does not depend exclusively on the presence of rich clusters within the survey sampled area. The most likely explanation for the observed excess in number counts at 1.1-mm is galaxy–galaxy and galaxy–group lensing at moderate amplification levels, which increases in amplitude as one samples larger and larger flux densities. This effect should also be detectable in other high-redshift populations.

Additional Information

© 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2011 RAS. Accepted 2011 April 28. Received 2011 April 26; in original form 2011 February 4. Article first published online: 19 Jul 2011. This work has been supported in part by Conacyt (Mexico) grants 39953-F and 39548-F, NSF (USA) grants AST-0907952 and AST-0838222, and by the MEXT Grant-in-Aid for Specially Promoted Research (No. 20001003). Observations with ASTE carried out remotely from Japan used NNT's GEMnet2 and its partner R&E networks, which are based on the AccessNova collaboration of the University of Chile, NTT Laboratories and the NOAJ. We would like to thank everyone who supported the AzTEC/ASTE observations of the COSMOS field, including E. Akiyama, R. Cybulski, K. Fukue, S. Harasawa, S. Ikarashi, H. Inoue, M. Kawamura, A. Kuboi, J. Rand, M. Tashiro, T. Tosaki, T. Tsukagoshi, Y. Shimajiri and C. Williams. The ASTE project is driven by the Nobeyama Radio Observatory (NRO), a branch of the National Astronomical Observatory of Japan (NAOJ), in collaboration with the University of Chile and Japanese institutions including the University of Tokyo, Nagoya University, Osaka Prefecture University, Ibaraki University and Hokkaido University.

Attached Files

Published - Aretxaga2011p15879Mon_Not_R_Astron_Soc.pdf


Files (3.8 MB)
Name Size Download all
3.8 MB Preview Download

Additional details

August 22, 2023
October 24, 2023