An automated archival VLA transients survey

Abstract

In this paper we present the results of a survey for radio transients using data obtained from the Very Large Array archive. We have reduced, using a pipeline procedure, 5037 observations of the most common pointings - i.e. the calibrator fields. These fields typically contain a relatively bright point source and are used to calibrate `target' observations: they are therefore rarely imaged themselves. The observations used span a time range ~ 1984 - 2008 and consist of eight different pointings, three different frequencies (8.4, 4.8 and 1.4 GHz) and have a total observing time of 435 hours. We have searched for transient and variable radio sources within these observations using components from the prototype LOFAR transient detection system. In this paper we present the methodology for reducing large volumes of Very Large Array data; and we also present a brief overview of the prototype LOFAR transient detection algorithms. No radio transients were detected in this survey, therefore we place an upper limit on the snapshot rate of GHz frequency transients > 8.0 mJy to rho less than or equal to 0.032 deg^-2 that have typical timescales 4.3 to 45.3 days. We compare and contrast our upper limit with the snapshot rates - derived from either detections or non-detections of transient and variable radio sources - reported in the literature. When compared with the current Log N - Log S distribution formed from previous surveys, we show that our upper limit is consistent with the observed population. Current and future radio transient surveys will hopefully further constrain these statistics, and potentially discover dominant transient source populations. In this paper we also briefly explore the current transient commissioning observations with LOFAR, and the impact they will make on the field.

Accepted for publication in MNRAS

References in corpus (33)

• Exploring the Optical Transient Sky with the Palomar Transient Factory
• Transient radio bursts from rotating neutron stars
• The VLA Low-frequency Sky Survey
• Science with ASKAP - the Australian Square Kilometre Array Pathfinder
• The Murchison Widefield Array: Design Overview
• An expanding radio nebula produced by a giant flare from the magnetar SGR 1806-20
• Orphan GRB radio afterglows: Candidates and constraints on beaming
• A new source detection algorithm using FDR
• The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
• A Complete Survey of the Transient Radio Sky and Implications for Gamma-Ray Bursts, Supernovae, and other Relativistic Explosions
• SubmilliJansky Transients in Archival Radio Observations
• A Giant Outburst at Millimeter Wavelengths in the Orion Nebula
• MeerKAT Key Project Science, Specifications, and Proposals
• The Dynamic Radio Sky
• Variability of sub-mJy radio sources
• X-ray and radio variability in the low luminosity Active Galactic Nucleus NGC 7213
• The Allen Telescope Array Twenty-centimeter Survey - A 690-Square-Degree, 12-Epoch Radio Dataset - I: Catalog and Long-Duration Transient Statistics
• APERTIF, a focal plane array for the WSRT
• GCRT J1742-3001: A New Radio Transient Towards the Galactic Center
• Bright Giant Pulses from the Crab Nebula Pulsar: Statistical Properties, Pulse Broadening and Scattering due to the Nebula
• A Radio Transient 0.1 pc from Sagittarius A*
• Optical Properties of faint FIRST Variable Radio Sources
• Low-Frequency Radio Transients in the Galactic Center
• A Search for Radio Emission from Supernovae With Ages from About One Week to More Than 80 Years
• A Search for Radio Transients in VLA Archival Images of the 3C 286 Field
• Surveying the Dynamic Radio Sky with the Long Wavelength Demonstrator Array
• A deep, high resolution survey of the low frequency radio sky
• Variable Radio Sources in the Galactic Plane
• Radio and X-ray variability in the Seyfert galaxy NGC 4051
• Long duration radio transients lacking optical counterparts are possibly Galactic Neutron Stars
• The Allen Telescope Array Pi GHz Sky Survey I. Survey Description and Static Catalog Results for the Bootes Field
• LOFAR Transients and the Radio Sky Monitor
• The Radio Sky on Short Timescales with LOFAR: Pulsars and Fast Transients

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• New methods to constrain the radio transient rate: results from a survey of four fields with LOFAR
• Millimeter Transient Point Sources in the SPTpol 100 Square Degree Survey
• Discovery of a Meter-Wavelength Radio Transient in the SWIRE Deep Field: 1046+59
• A search for variable and transient radio sources in the extended Chandra Deep Field South at 5.5 GHz
• The Allen Telescope Array Pi GHz Sky Survey II. Daily and Monthly Monitoring for Transients and Variability in the Bootes Field
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• CHILES VERDES: Radio variability at an unprecedented depth and cadence in the COSMOS field
• ASGARD: A Large Survey for Slow Galactic Radio Transients. I. Overview and First Results
• The Allen Telescope Array Pi GHz Sky Survey - III: The ELAIS-N1, Coma, and Lockman Hole Fields
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• Search and identification of transient and variable radio sources using MeerKAT observations: a case study on the MAXI J1820+070 field
• Off-axis synchrotron light curves from full-time-domain moving-mesh simulations of jets from massive stars
• Radio Variable and Transient Sources on Minute Timescales in the ASKAP Pilot Surveys
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• Transient Events in Archival Very Large Array Observations of the Galactic Center
• Discovery of a radio transient in M81
• Radio Transients and Variables in the Tenth Deeper, Wider, Faster Observing Run
• X-ray Observations of Radio Transients without Optical Hosts
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• Multi-epoch Low Radio Frequency Surveys of the Kepler K2 Mission Campaign Fields 3, 4, and 5 with the Murchison Widefield Array