{
  "bibcode": "2017GCN.22115....1K",
  "body": "A. Keivani (PSU), D.B. Fox (PSU), J.J. DeLaunay (PSU), J.A. Kennea (PSU),\nP.A. Evans (U. Leicester),  D.F. Cowen (PSU), J.P. Osborne (U. Leicester),\nand F.E. Marshall (GSFC) report on behalf of the Swift-IceCube\ncollaboration:\n\nSwift has observed the field of the IceCube EHE event, IceCube-171106A\n(Revision 0, <https://gcn.gsfc.nasa.gov/notices_amon/50579430_130033.amon>\nhttps://gcn.gsfc.nasa.gov/notices_amon/17569642_130214.amon; subsequently\nupdated to Revision 1, GCN #22105), utilizing the on-board 19-point tiling\npattern to cover a region centered on RA,Dec (J2000) = (340.0d, +7.4d),\nwith a radius of approximately 0.8 degrees. Swift-XRT collected ~750 s per\nfield of PC mode data per tile. The observations were taken between 21:51:12\nUT on 2017 November 06 and 11:52:10 UT on 2017 November 07 (i.e. from 11.5\nks to 62.0 ks after the neutrino trigger), and covered 2.1 square degrees.\nFourteen X-ray sources are detected in the observations, of which five lie\nwithin the refined neutrino localization.\n\nOf the fourteen identified sources, two correspond to known X-ray emitters,\nX1 to 1RXS J224124.3+071253, and X3 to UGC 12138. Two further sources, X4\nand X14, have positions consistent with ROSAT Faint Source Catalog objects.\n\nFive further sources have potential counterparts from the SIMBAD database.\nX2 matches to HD 215109; detection of this optically bright star may be due\nto optical loading rather than bona fide X-ray emission. X5 matches to 87GB\n223537.9+070825 (5BZQJ2238+0724 in BZcat), which is a flat-spectrum radio\nquasar and known blazar, not previously reported to emit in X-rays. X6\nmatches to PMN J2243+0716, a radio-bright quasar. X8 matches to the GALEX\n���blue object��� source 2690384041306227301. X10 matches to WISE\nJ224206.68+073148.3, a known BL Lac-type blazar. Observing X-ray emission\n(or in the case of HD 215109, an optical loading detection) at the level\nseen here from any of these sources would not be remarkable.\n\nGiven the recent observation of high-energy gamma-ray activity from TXS\n0506+056, potentially associated with the high-energy neutrino\nIceCube-170922A (GCN #21916, ATel #10791, ATel #10817), we note in\nparticular the two X-ray luminous blazars within the neutrino localization,\n87GB 223537.9+070825 and WISE J224206.68+073148.3.\n\nIdentified sources:\n\nSource         RA            Dec           r_90 R_x** Catalog/Notes\n\n=================================================================\n\n X1* 22:41:24.15   +07:12:57.6 4.1��� 61(9) 1RXS J224124.3+071253\n\n X2 22:42:48.20 +06:40:14.2 4.4��� 82(3) HD 215109 (optical loading)\n\n X3 22:40:17.14 +08:03:13.4 2.1��� 410(3) UGC 12138\n\n X4 22:41:20.34 +06:48:58.7 5.4��� 32(9) 1RXS J224122.2+064851 (?)\n\n X5* 22:38:10.41 +07:24:12.8 5.2��� 30(8) 87GB 223537.9+070825\n\n X6 22:43:05.82 +07:16:34.7 5.7��� 9(5) PMN J2243+0716\n\n X7 22:37:54.30 +07:22:02.9 6.8��� ?\n\n X8 22:38:59.95 +07:02:43.7 6.3��� 4(4) GALEX 2690384041306227301\n\n X9* 22:38:47.59 +07:22:24.8 6.1��� ?\n\n X10* 22:42:06.68 +07:31:52.6 7.4��� 7(4) WISE J224206.68+073148.3\n\n X11 22:40:15.96 +07:48:42.2 5.9��� 9(4)\n\n X12 22:40:26.17 +06:50:14.3 5.9��� 4(4)\n\n X13 22:38:21.18 +08:04:20.7 4.9��� 3(5)\n\n X14* 22:39:52.53 +07:11:57.1 6.7��� 9(5) 1RXS J223951.8+071132 (?)\n\n=================================================================\n\n* inside the refined 90%-confidence neutrino localization\n\n** R_x indicate count rate in units of counts ks^-1.\n\nOf the identified sources, the following lie outside the refined\n90%-confidence neutrino localization reported by IceCube (GCN #22105):  X2,\nX3, X4, X6, X7, X8, X11, X12, X13. The remaining sources (indicated with\nasterisks by their source names) lie within the neutrino localization.\n\nExcluding identified sources, the 3-sigma upper limit on the count rate in\nthe rest of the field is 0.01 ct s^-1, which corresponds to a 0.3-10 keV\nflux of 4.1e-13 erg cm^-2 s^-1 for a typical AGN spectrum (NH=3e20 cm^-2,\nGamma=1.7). Overlaps between the different tiles account for 0.5 square\ndegrees: in these regions the 3-sigma upper limit is 0.009 ct s^-1,\ncorresponding to 3.7e-13 erg cm^-2 s^-1.\n\nThe neutrino localization was in the Swift's Burst Alert Telescope's (BAT)\nfield of view from 404 seconds to 117 seconds prior to the EHE alert time.\nThere were no triggered GRBs during this time. Using the 287 second BAT\nsurvey exposure (starting at 18:32:55 UT on 2017 November 06) we searched\nfor any hard X-ray emission inside the 90%-confidence neutrino\nlocalization. We found no point source and set a 4-sigma upper limit on the\nfluence during that time period of 5e-7 erg cm^-2 (15-150 keV) assuming a\nphoton index of -2.",
  "circularId": 22115,
  "createdOn": 1510273492000,
  "email": "keivani@psu.edu",
  "subject": "IceCube-171106A: Swift Observations",
  "submitter": "Azadeh Keivani at PSU  <keivani@psu.edu>",
  "eventId": "IceCube-171106A"
}