Title:	Limits on fast radio bursts and other transient sources at 182 MHz using the Murchison widefield array
Authors:	Rowlinson, A. Bell, M.E. Deshpande, A.A. Udaya Shankar, N. Srivani, K.S. Subrahmanyan, Ravi Prabu, T. +30 Co-authors
Keywords:	instrumentation: interferometers techniques image processing catalogues radio continuum: 24 months
Issue Date:	Jun-2016
Publisher:	Oxford University Press for The Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2016, Vol. 458, p 3506-3522
Abstract:	We present a survey for transient and variable sources, on time-scales from 28 s to ∼1 yr, using the Murchison Widefield Array (MWA) at 182 MHz. Down to a detection threshold of 0.285 Jy, no transient candidates were identified, making this the most constraining low-frequency survey to date and placing a limit on the surface density of transients of <4.1 × 10−7 deg−2 for the shortest time-scale considered. At these frequencies, emission from Fast Radio Bursts (FRBs) is expected to be detectable in the shortest time-scale images without any corrections for interstellar or intergalactic dispersion. At an FRB limiting flux density of 7980 Jy, we find a rate of <82 FRBs per sky per day for dispersion measures <700 pc cm−3. Assuming a cosmological population of standard candles, our rate limits are consistent with the FRB rates obtained by Thornton et al. if they have a flat spectral slope. Finally, we conduct an initial variability survey of sources in the field with flux densities ≳0.5 Jy and identify no sources with significant variability in their light curves. However, we note that substantial further work is required to fully characterize both the short-term and low-level variability within this field.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/6459
ISSN:	0035-8711 1365-2966 - (online)
Alternative Location:	http://adsabs.harvard.edu/abs/2016MNRAS.458.3506R http://arxiv.org/abs/1602.07544 http://dx.doi.org/10.1093/mnras/stw451
Copyright:	2016 The authors & the Royal Astronomical Society.
Appears in Collections:	Research Papers (A&A)

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