BRIGHT SOURCE SUBTRACTION REQUIREMENTS FOR REDSHIFTED 21 cm MEASUREMENTS

Journal Article · Sat Nov 20 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/724/1/526· OSTI ID:21471175

Datta, A ^[1]; Bowman, J D ^[2]

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1. New Mexico Tech, Socorro, NM 87801 (United States)
2. California Institute of Technology, Pasadena, CA 91125 (United States)

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 ({approx}>1 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{sub perpendicular} {approx}> 0.05 Mpc{sup -1}, in the two-dimensional power spectrum.

• OSTI ID: 21471175
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 724; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANTENNAS
ASTROPHYSICS
CALIBRATION
DATA ANALYSIS
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
PHYSICS
POINT SOURCES
RADIATION SOURCES
RADIO EQUIPMENT
RADIO TELESCOPES
RED SHIFT
SIGNALS
TELESCOPES
UNIVERSE