{
  "bibcode": "2020GCN.26787....1E",
  "body": "P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U.\nToronto), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester),\nM.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), P. Brown (TAMU),\nD.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G.\nCusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),\nV. D'Elia(ASDC), S.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall\n(PSU), D. Hartmann (U. Clemson), H.A. Krimm (CRESST/GSFC/USRA), N.J.\nKlingler (PSU), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E.\nMarshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R.\nOates (U. Birmingham), P.T. O'Brien (U. Leicester), J.P. Osborne (U.\nLeicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), M.J.Page\n(UCL-MSSL), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin\n(NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G.\nTagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP) report on behalf of\nthe Swift team:\n\nSwift has carried out 206 observations of the LVC error region for the\nGW trigger S200114f following the 'cWB' (version 3) GW localisation\nmap. The observations currently span from 6.6 ks to 99 ks after the LVC\ntrigger, and the XRT has covered 22.3 deg^2 on the sky (corrected for\noverlaps). This covers 30% of the probability in the 'cWB' (version 3)\nskymap. These pointings and associated metadata have been reported to\nthe Treasure Map (Wyatt et al., arXiv 2001.00588;\nhttp://treasuremap.space/alerts?graceids=S200114f).\n\nA 'rank 2' source has been found, so classified because it shows\nindications of fading, however it is spatially consistent with a source\nin the WISE AGN candidates catalogs (Assef et al., 2018) and therefore\nmay simply be a variable AGN. The details of this source are:\n  \n  Source 2:\n  =============\n    RA: \t 110.3641 ( = 07h 21m 27.38s) J2000\n    Dec:\t +17.0360 ( = +17d 02' 09.6\") J2000\n    Error:\t 7.0 (arcsec, radius, 90% confidence).\n    Peak Rate:\t 9.6e-02 +/- 1.7e-02 ct/sec (0.3-10 keV)\n    Peak Flux:\t 4.1e-12 +/- 7.5e-13 erg cm^-2 s^-1 (0.3-10 keV)\n    Catalogued:  No\n    RASS UL:\t 3.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV)\n\n\nFurther observations of this source are scheduled.\n\nIn total, we have detected 8 X-ray sources. Each source is assigned a\nrank of 1-4 which describes how likely it is to be related to the GW\ntrigger, with 1 being the most likely and 4 being the least likely. The\nranks are described at https://www.swift.ac.uk/ranks.php.\n\nWe have found:\n\n  * 0 sources of rank 1\n  * 1 source of rank 2\n  * 6 sources of rank 3\n  * 1 source of rank 4\n\n\nRANK 3 sources\n==============\n\nThese are uncatalogued X-ray sources, however they are not brighter\nthan previous upper limits, so do not stand out as likely counterparts\nto the GW trigger.\n\n| Source ID\t | RA\t\t  | Dec \t   | Err90   |\n|  S200114f_X1\t | 07h 13m 48.09s | +23d 04' 50.5\" |\t7.5\" |\n|  S200114f_X10  | 03h 41m 58.28s | -25d 24' 17.6\" |\t6.1\" |\n|  S200114f_X46  | 03h 41m 1.50s  | -25d 26' 54.4\" |\t6.4\" |\n|  S200114f_X56  | 07h 22m 51.63s | +16d 15' 51.0\" |\t6.3\" |\n|  S200114f_X57  | 07h 23m 54.09s | +16d 22' 00.1\" |\t7.7\" |\n|  S200114f_X58  | 07h 23m 50.42s | +16d 21' 17.1\" |\t6.7\" |\n\n\nRANK 4 sources\n==============\n\nThese are catalogued X-ray sources, showing no signs of outburst\ncompared to previous observations, so they are not likely to be related\nto the GW trigger.\n\n| Source ID\t | RA\t\t  | Dec \t   | Err90   |\n|  S200114f_X59  |  07h 15m 9.23s | +15d 55' 36.9\" |\t8.3\" |\n\nThe Swift-XRT observations also covered the locations of 6 sources\nreported by other observers, thus:\n\n* AT2020vr (GCN26741)\t\tF < 3.3x10^-12 erg cm^-2 s^-1.\n* AT2020vs (GCN26741)\t\tF < 2.0x10^-12 erg cm^-2 s^-1.\n* AT2020vt (GCN26741)\t\tF < 4.2x10^-12 erg cm^-2 s^-1.\n* AT2020vu (GCN26741)\t\tF < 8.6x10^-12 erg cm^-2 s^-1.\n* AT2020vw (GCN26741)\t\tF < 4.7x10^-12 erg cm^-2 s^-1.\n* AT2020wc (GCN26741)\t\tF < 1.7x10^-11 erg cm^-2 s^-1.\n\nFlux limits are 3-sigma upper limits on the 0.3-10 keV observed flux.\n\nFor all flux conversions and comparisons with catalogues and upper\nlimits from other missions, we assumed a power-law spectrum with\nNH=3x10^20 cm^-2, and photon index (Gamma)=1.7\n\nThe results of the XRT automated analysis, including details of the\nsources listed above, are online at\nhttps://www.swift.ac.uk/LVC/S200114f\n\nThis circular is an official product of the Swift XRT team.",
  "circularId": 26787,
  "createdOn": 1579185556000,
  "email": "pae9@leicester.ac.uk",
  "subject": "LIGO/Virgo S200114f: Swift-XRT sources and observations",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "LIGO/Virgo S200114f"
}