{
  "bibcode": "2020GCN.26700....1S",
  "body": "IceCube-200109A: Swift-XRT and UVoT Follow-up Observations\n\nP. A. Evans (U. Leicester), A. Keivani (Columbia U.), J. A. Kennea (PSU),\nF. E. Marshall (NASA/GSFC), and D. B. Fox (PSU), report:\n\nThe Neil Gehrels Swift Observatory observed the field of the IceCube\nAstrotrack Gold astrophysical neutrino candidate event IceCube-200109A\n(revision 1, https://gcn.gsfc.nasa.gov/gcn3/26696.gcn3) beginning Jan 10,\n05:55:10 UT (~6 hours after the neutrino arrival time).\n\nSwift utilized a 35-point tiling pattern to cover a region centered on\nR.A., Dec. (J2000) = 164.49d, 11.87d, with a radius of approximately 66\narcmin; estimated 90%-containment error region for this event is rather\nlarge with asymmetric (+4.94d, -4.19d) on RA and (+1.16, -1.36) on Dec.\nSwift-XRT collected ~230 s per field of PC-mode data per tile (except for\none tile which only 8 s were obtained). The X-ray data have been reduced\nusing the analysis approach and software routines of Evans et al. 2014\n(ApJS, 210, 8).\n\nOnly one X-ray source (RA = 165.34231 deg, Dec = 12.58648 deg) is detected\nin the field of observation, which is consistent with a double or multiple\nstar (HEI 155; 1.5 arcsec away) which is also 18.8 arcsec away from a known\nX-ray source 1RXS J110123.1+123524 from ROSAT/RASSFSC. This is not\nconsidered as a source of interest.\n\nExcluding the identified source, the 3-sigma upper limit on the count rate\nof any point-like counterpart over the rest of the tiled region is 0.03 ct\ns^-1, which corresponds to a 0.3-10 keV flux of 1.2e-12 erg cm^-2 s^-1 for\na typical AGN spectrum (nH=3e20 cm^-2, Gamma=1.7).\n\nSwift/UVOT co-observed with XRT (with a slightly smaller field-of-view)\nusing the U filter. The exposures are ~219 s except for one tile (target ID\n00013102), for which only 8 s were obtained. No uncatalogued sources were\nfound with a limiting magnitude of about 18.9 for the typical field and\n17.5 for target ID 00013102.",
  "circularId": 26700,
  "createdOn": 1578695991000,
  "email": "azadeh.keivani@columbia.edu",
  "subject": "IceCube-200109A: Swift-XRT and UVoT Follow-up Observations",
  "submitter": "Azadeh Keivani at Columbia U  <azadeh.keivani@columbia.edu>",
  "eventId": "IceCube-200109A"
}