Source subtraction for the extended Very Small Array and 33-GHz source count estimates

Authors

Errata

This article is corrected by:

  1. Errata: Erratum: Source subtraction for the extended Very Small Array and 33-GHz source count estimates Volume 386, Issue 3, 1759–1760, Article first published online: 14 April 2008

E-mail: Kieran.A.Cleary@jpl.nasa.gov

Present address: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena CA 91109.

Present address: Astrophysics Group, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH.

Present address: California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA.

Present address: Astrophysics Group, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH.

Present address: Faculty of Mathematics & Physics, University of Ljubljana, 1000 Ljubljana, Slovenia.

Present address: Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain.

ABSTRACT

We describe the source subtraction strategy and observations for the extended Very Small Array (VSA), a cosmic microwave background interferometer operating at 33 GHz. A total of 453 sources were monitored at 33 GHz using a dedicated source subtraction baseline. 131 sources brighter than 20 mJy were directly subtracted from the VSA visibility data. Some characteristics of the subtracted sources, such as spectra and variability, are discussed. The 33-GHz source counts are estimated from a sample selected at 15 GHz. The selection of VSA fields in order to avoid bright sources introduces a bias into the observed counts. This bias is corrected and the resulting source count is estimated to be complete in the flux-density range 20–114 mJy. The 33-GHz source counts are used to calculate a correction to the VSA power spectrum for sources below the subtraction limit.

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