A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz
Name
Hewitt_A survey.pdf
Size
953.47 KB
Format
Adobe PDF
Checksum (MD5)
a4cca2ad1a79d6f8908da400ff819e32
Author(s)
Bowman, Judd D.
Goeke, Robert F.
Hewitt, Jacqueline N.
Morgan, Edward H.
Remillard, Ronald Alan
Williams, Christopher Leigh
Date Issued
December 2013
Journal
Monthly Notices of the Royal Astronomical Society
Publisher
Oxford University Press
Citation
Bell, M. E., T. Murphy, D. L. Kaplan, P. Hancock, B. M. Gaensler, J. Banyer, K. Bannister, et al. “A Survey for Transients and Variables with the Murchison Widefield Array 32-Tile Prototype at 154 MHz.” Monthly Notices of the Royal Astronomical Society 438, no. 1 (February 11, 2014): 352–367.
Version
Author's final manuscript
Abstract
We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. 51 images were obtained that cover a field of view of 1430 deg[superscript 2] centred on Hydra A. The observations were obtained over three days in 2010 March and three days in 2011 April and May. The mean cadence of the observations was 26 min and there was additional temporal information on day and year time-scales. We explore the variability of a sample of 105 low-frequency radio sources within the field. Four bright (S > 6 Jy) candidate variable radio sources were identified that displayed low levels of short time-scale variability (26 min). We conclude that this variability is likely caused by simplifications in the calibration strategy or ionospheric effects. On the time-scale of 1 yr we find two sources that show significant variability. We attribute this variability to either refractive scintillation or intrinsic variability. No radio transients were identified and we place an upper limit on the surface density of sources ρ < 7.5 × 10[superscript −5] deg[superscript −2] with flux densities >5.5 Jy, and characteristic time-scales of both 26 min and 1 yr.
MIT Department
Haystack Observatory
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1093/mnras/stt2200
