Letter to the Editor
Star-forming regions near GRB 990123 *
Stephen Holland 1 and
Jens Hjorth 2
Received 23 February 1999 / Accepted 11 March 1999
We reduced the Hubble Space Telescope Space Telescope Imaging Spectrograph images of the gamma-ray burst GRB 990123 that were obtained on 8-9 February 1999 and find , which corresponds to a flux of µJy for the optical transient 16.644 days after the burst's peak. The probable host galaxy has ( µJy) and the optical transient is located ( kpc) south of the galaxy's nucleus. We fit and subtracted a scaled point-spread function to the optical transient and found evidence for three bright knots situated within ( kpc) of the optical transient. Each knot has , a rest-frame V-band luminosity of -, and a star-formation rate of at least - yr-1. The knots are centrally concentrated with full-width at half-maximum of ( kpc). Their sizes and luminosities are consistent with their being star-forming regions. The optical transient is located ( kpc) southeast of the centre of one of these knots.
Key words: gamma rays: bursts galaxies: starburst
* Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.
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© European Southern Observatory (ESO) 1999
Online publication: March 29, 1999