{
  "bibcode": "2022GCN.32691....1S",
  "body": "Volodymyr Savchenko (UNIGE, EPFL), Carlo Ferrigno, Enrico Bozzo (UNIGE), \nD. Gotz (CEA Paris Saclay), S. Mereghetti (INAF/IASF Milano),�� Antonio \nMartin Carrillo, Lorraine Hanlon (UCD), Elisabeth Jourdain, Jean-Pierre \nRoques (IRAP), Thomas Siegert (University of W��rzburg), Erik Kuulkers, \nCelia Sanchez (ESA)\n\n\nFollowing the detection of the record-breaking GRB221009A by Swift/BAT \n(GCN #32632,#32635), Fermi/GBM (GCN #32636),\nINTEGRAL/SPI-ACS (GCN #32660), we have performed INTEGRAL pointed \nobservations of the GRB221009A location.\n\nINTEGRAL pointed observation lasted from 2022-10-10T14:31:40 (T0 + 25.2 \nhours, where T0 is 2022-10-09T13:17:00) to 2022-10-11T03:18:20 (T0 + \n38.0 hours) with a total exposure time of 30.2 ks (for ISGRI).\n\nIn the complete observation, the source is clearly detected in JEM-X1, \nJEM-X2 (3-30 keV), and ISGRI (28 - 80 keV), with S/N of 27.8, 27.3, 15.0 \nrespectively.\n\nThe joint JEM-X and ISGRI spectra can be satisfactorily modeled between \n3 and 80 keV with a single powerlaw of slope 2.15 +/- -0.07 (90% \nconfidence) with a flux of 4.4e-10 +/- -2.1e-11 erg/cm2/s (3 - 80 keV).\nThis might indicate a single spectral component spanning from from hard \nX-ray to Fermi/LAT (GCN #32658).\n\nCombination of bright Hard X-ray afterglow with gamma-ray emission was \nalso found in GRB120711A (Martin-Carrillo et al. 2014 A&A 567, 84) and \nGRB130427A (Kouveliotou et al. 2013 ApJ 779L, 1K)\n- in fact GRB221009A appears rather similar to GRB120711A, but at 10 \ntimes smaller distance.\n\nWithin the relatively short JEM-X not ISGRI lightcurves, we do not \nobserve any evidence for flux decrease.\n\nFurther INTEGRAL observations are scheduled between 2022-10-11 13:52:21 \nand 2022-10-13 00:58:26. These observations will overlap with the \nplanned observation of IXPE (GCN #32690).\n\nWe are grateful to the INTEGRAL Ground Segment team for quickly \nscheduling the observations.\n\nImages and reduced data related to this publication can be found here: \nhttps://zenodo.org/record/7186289",
  "circularId": 32691,
  "createdOn": 1665504323000,
  "email": "savchenk@in2p3.fr",
  "subject": "GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger",
  "submitter": "Volodymyr Savchenko at ISDC,U of Geneve  <savchenk@in2p3.fr>",
  "eventId": "GRB 221009A"
}