No Radio Afterglow from the Gamma-Ray Burst of February 28, 1997

Abstract

We present radio observations of the gamma-ray burster GRB 970228 made with the Very Large Array (VLA) and the Owens Valley Radio Observatory (OVRO) spanning a range of postburst timescales from one to 300 days. A search for a time-variable radio source was conducted covering an area which included a fading X-ray source and an optical transient, both of which are thought to be the long wavelength counterparts to the gamma-ray burst. At the position of the optical transient sensitive limits between 10 uJy and 1 mJy can be placed on the absence of a radio counterpart to GRB 970228 between 1.4 and 240 GHz. We apply a simple formulation of a fireball model which has been used with some success to reproduce the behavior of the optical and X-ray light curves. Using this model we conclude that the radio non-detections are consistent with the peak flux density of the afterglow lying between 20-40 uJy and it requires that the optical flux peaked between 4 and 16 hours after the burst.

ApJ Let (submitted)

References in corpus (15)

• Spectra and Light Curves of Gamma-Ray Burst Afterglows
• Discovery of the X-Ray Afterglow of the Gamma-Ray Burst of February 28 1997
• Shocked by GRB 970228: the afterglow of a cosmological fireball
• GRB after-glow: Supporting the cosmological fireball model, constraining parameters, and making predictions
• Gamma-ray burst after-glow: Confirming the cosmological fireball model
• Implications of the radio afterglow from the gamma-ray burst of May 8, 1997
• Radio scintillation of gamma-ray-burst afterglows
• The afterglow of gamma ray bursts II: the cases of GRB 970228 and GRB 970508
• The decay of optical emission from the Gamma-Ray Burst GRB 970228
• Spectral Properties of the Prompt X-ray emission and Afterglow from the Gamma-Ray Burst of 28 February 1997
• Observations and Theoretical Implications of GRB 970228
• Power Law Decays in the Optical Counterparts of GRB 970228 and GRB970508
• 3rd Interplanetary Network Localization, Time History, Fluence, Peak Flux, and Distance Lower Limit of the February 28, 1997 Gamma-Ray Burst
• Theoretical Models of Gamma-Ray Bursts
• Afterglows as Diagnostics of Gamma Ray Burst Beaming

Cited by in corpus (3)

• Wind Interaction Models for Gamma-Ray Burst Afterglows: The Case for Two Types of Progenitors
• The redshift and the ordinary host galaxy of GRB 970228
• The star-formation rate in the host of GRB 990712