Bright Source Subtraction Requirements for Redshifted 21 cm Measurements
- Creators
- Datta, A.
- Bowman, J. D.
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Carilli, C. L.
Abstract
The H I 21 cm transition line is expected to be an important probe into the cosmic dark ages and epoch of reionization. Foreground source removal is one of the principal challenges for the detection of this signal. This paper investigates the extragalactic point source contamination and how accurately bright sources (≳ Jy) must be removed in order to detect 21 cm emission with upcoming radio telescopes such as the Murchison Widefield Array. We consider the residual contamination in 21 cm maps and power spectra due to position errors in the sky model for bright sources, as well as frequency-independent calibration errors. We find that a source position accuracy of 0.1 arcsec will suffice for detection of the H I power spectrum. For calibration errors, 0.05% accuracy in antenna gain amplitude is required in order to detect the cosmic signal. Both sources of subtraction error produce residuals that are localized to small angular scales, k⊥ ≳ 0.05 Mpc^(–1), in the two-dimensional power spectrum.
Additional Information
© 2010 American Astronomical Society. Received 2010 May 21; accepted 2010 September 17; published 2010 November 3. A.D. and C.L.C. are grateful for support from the Max- Planck Society and the Alexander von Humboldt Foundation through the Max Planck Forshungspreise 2005. J.D.B. is supported by NASA through Hubble Fellowship grant HF- 01205.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. The National Radio Astronomy Observatory is operated by Associated Universities, Inc., under cooperative agreement with the National Science Foundation. A.D. is grateful for support from NRAO through the graduate-intern program.Attached Files
Published - Datta2010p12066Astrophys_J.pdf
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Additional details
- Eprint ID
- 21170
- Resolver ID
- CaltechAUTHORS:20101206-095846998
- Max-Planck Society
- Max Planck Forshungspreise 2005
- Alexander von Humboldt Foundation
- Hubble Fellowship grant HF- 01205.01-A
- NASA
- Space Telescope Science Institute
- Created
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2010-12-06Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field