The ASKAP Variables and Slow Transients (VAST) Pilot Survey
Abstract
The Variables and Slow Transients Survey (VAST) on the Australian Square Kilometre Array Pathfinder (ASKAP) is designed to detect highly variable and transient radio sources on timescales from 5 seconds to years. In this paper, we present the survey description, observation strategy and initial results from the VAST Phase I Pilot Survey. This pilot survey consists of hours of observations conducted at a central frequency of 888~MHz between 2019 August and 2020 August, with a typical rms sensitivity of 0.24~mJy~beam and angular resolution of arcseconds. There are 113 fields, \red{each of which was observed for 12 minutes integration time}, with between 5 and 13 repeats, with cadences between 1 day and 8 months. The total area of the pilot survey footprint is 5\,131 square degrees, covering six distinct regions of the sky. An initial search of two of these regions, totalling 1\,646 square degrees, revealed 28 highly variable and/or transient sources. Seven of these are known pulsars, including the millisecond pulsar J2039--5617. Another seven are stars, four of which have no previously reported radio detection (SCR~J0533--4257, LEHPM~2-783, UCAC3~89--412162 and 2MASS J22414436--6119311). Of the remaining 14 sources, two are active galactic nuclei, six are associated with galaxies and the other six have no multiwavelength counterparts and are yet to be identified.
Cite
@article{arxiv.2108.06039,
title = {The ASKAP Variables and Slow Transients (VAST) Pilot Survey},
author = {Tara Murphy and David L. Kaplan and Adam J. Stewart and Andrew O'Brien and Emil Lenc and Sergio Pintaldi and Joshua Pritchard and Dougal Dobie and Archibald Fox and James K. Leung and Tao An and Martin E. Bell and Jess W. Broderick and Shami Chatterjee and Shi Dai and Daniele d'Antonio and J. Gerry Doyle and B. M. Gaensler and George Heald and Assaf Horesh and Megan L. Jones and David McConnell and Vanessa A. Moss and Wasim Raja and Gavin Ramsay and Stuart Ryder and Elaine M. Sadler and Gregory R. Sivakoff and Yuanming Wang and Ziteng Wang and Michael S. Wheatland and Matthew Whiting and James R. Allison and C. S. Anderson and Lewis Ball and K. Bannister and D. C. -J. Bock and R. Bolton and J. D. Bunton and R. Chekkala and A. P. Chippendale and F. R. Cooray and N. Gupta and D. B. Hayman and K. Jeganathan and B. Koribalski and K. Lee-Waddell and Elizabeth K. Mahony and J. Marvil and N. M. McClure-Griffiths and P. Mirtschin and A. Ng and S. Pearce and C. Phillips and M. A. Voronkov},
journal= {arXiv preprint arXiv:2108.06039},
year = {2021}
}