XMM-Newton Observation of GRB050223


  • GRB050223 was detected by the Swift BAT instrument at 03:09:06UTC on 23 Feb 2005 (GCN 3054).
  • XMM_Newton observed GRB050223 between Feb. 23 13:04UT and Feb. 24 06:15UT, with a gap due to the ground station not being available as it was urgently required in support of INTEGRAL between Feb. 23 16:54UT and Feb. 23 18:56UT.
  • the observation was performed to make use of time left over in an engineering test window.
  • Real Time monitoring data showed a source near the instruments' boresight. A quick look analysis of these data resulted in estimates for the position and count rate of this source of (GCN 3060)
       R.A. = 18h 05m 32.5s
       DEC. = -62° 28' 21"
       rate ~ 0.03counts/sec
    where coordinates are J2000 and the rate refers to EPIC-pn in the range 0.3-8keV


  • The Observation Data File (ODF) will be available in the XSA here.
  • And the Pipeline Products will be available in the XSA here.

Please Note: a reprocessed ODF has been made available in the XSA as of 18-Mar-2005.

Quick analysis of preliminary XMM-Newton data

EPIC-pn image

A minimum event filtering has been applied to generate this image. The dashed circle shows the "aperture" used to generate the lightcurve and spectrum.

PN light curve

Light curves from PN data have been generated for three energy bands: 0.3-8keV, 0.3-3.keV and 3.0-8.0keV. In spite the low count rate, the soft and hard energy bands seem to have different behaviour: for the soft band there seem to be two "states" at 0.027cts/sec and 0.014cts/sec, with the change somewhere in the data gap. The high energy band seems to brighten during the first 10ksec and fade after 25ksec, with the turning point again somewhere in the gap.

EPIC-pn spectrum

We have fitted the pn spectrum of GRB050223 with a power law and absorption. The Hydrogen column density obtained in the fit is ~1.4 x 1020 cm-2 , lower than the galactic value in this direction (~7.1 x 1020 cm-2). The flux in the 2-10 keV band is approximately 1.3 x 10-13 erg cm-2 s-1 for a power law photon index of 1.1.