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Exploiting magnification bias in ultradeep submillimetre-wave surveys using ALMA

Blain, A. W. (2002) Exploiting magnification bias in ultradeep submillimetre-wave surveys using ALMA. Monthly Notices of the Royal Astronomical Society, 330 (1). pp. 219-224. ISSN 0035-8711. doi:10.1046/j.1365-8711.2002.05058.x.

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The surface density of populations of galaxies with steep/shallow source counts is increased/decreased by gravitational lensing magnification. These effects are usually called ‘magnification bias’ and ‘depletion’, respectively. However, if sources are demagnified by lensing, then the situation is reversed, and the detectable surface density of galaxies with a shallow source count, as expected at the faintest flux densities, is increased. In general, demagnified sources are difficult to detect and study: exquisite subarcsec angular resolution and surface brightness sensitivity are required, and emission from the lensing object must not dominate the image. These unusual conditions are expected to be satisfied for observations made of the dense swarm of demagnified images that could form very close to the line of sight through the centre of a rich cluster of galaxies using the forthcoming submillimetre-wave Atacama Large Millimeter Array (ALMA) interferometer. The demagnified images of most of the background galaxies lying within about 1 arcmin of a rich cluster of galaxies could be detected in a single 18-arcsec-diameter ALMA field centred on the cluster core, providing an effective increase in the ALMA field of view. This technique could allow a representative sample of faint, 10–100 μJy submillimetre galaxies to be detected several times more rapidly than in a blank field.

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URLURL TypeDescription Paper
Blain, A. W.0000-0001-7489-5167
Additional Information:© 2002 RAS. Accepted 2001 October 18. Received 2001 October 17; in original form 2001 May 30. Thanks to Ole Möller, Priya Natarajan, Kate Quirk and an anonymous referee for valuable comments on the manuscript. AWB acknowledges generous support from the Raymond and Beverly Sackler Foundation as part of the Deep Sky Initiative programme at the IoA.
Funding AgencyGrant Number
Raymond and Beverly Sackler FoundationUNSPECIFIED
Subject Keywords:gravitational lensing, methods: observational, galaxies: clusters: general, cosmology: observations, infrared: galaxies, radio continuum: galaxies
Issue or Number:1
Record Number:CaltechAUTHORS:20170408-193319893
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Official Citation:A.W. Blain; Exploiting magnification bias in ultradeep submillimetre-wave surveys using ALMA, Monthly Notices of the Royal Astronomical Society, Volume 330, Issue 1, 11 February 2002, Pages 219–224,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:76366
Deposited By: 1Science Import
Deposited On:29 Mar 2018 23:51
Last Modified:15 Nov 2021 16:59

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