The star-formation rate in the host of GRB 990712

¹ Astronomical Institute "Anton Pannekoek" , University of Amsterdam & Center for High Energy Astrophysics, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
² Joint Institute for VLBI in Europe (JIVE), Postbus 2, 7990 AA, Dwingeloo, The Netherlands
³ Australia Telescope National Facility, Paul Wild Observatory, Locked Bag 194, Narrabri, NSW 2390, Australia
⁴ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

Corresponding author: P. M. Vreeswijk pmv@astro.uva.nl

Received: 13 August 2001
Accepted: 23 October 2001

Abstract

We have observed the host galaxy of GRB 990712 at 1.4 GHz with the Australia Telescope Compact Array, to obtain an estimate of its total star-formation rate. We do not detect a source at the position of the host. The 2σ upper limit of 70 μJy implies that the total star-formation rate is lower than 100 yr^-1, using conservative values for the spectral index and cosmological parameters. This upper limit is in stark contrast with recent reports of radio/submillimeter-determined star-formation rates of ~500 yr^-1 for two other GRB host galaxies. Our observations present the deepest radio-determined star-formation rate limit on a GRB host galaxy yet, and show that also from the unobscured radio point-of-view, not every GRB host galaxy is a vigorous starburst.