{
  "bibcode": "2024GCN.36837....1E",
  "createdOn": 1720517830677,
  "eventId": "LIGO/Virgo S240615dg",
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "circularId": 36837,
  "body": "P.A. Evans (U. Leicester), K.L. Page (U. Leicester), J.A. Kennea (PSU),\nA. Tohuvavohu (U. Toronto), S.B. Cenko (NASA/GSFC), R.A.J. Eyles-Ferris\n(U. Leicester), A.P. Beardmore (U. Leicester), M.G. Bernardini\n(INAF-OAB), A.A. Breeveld (UCL-MSSL), S. Campana (INAF-OAB), J.J.\nDelaunay (PSU), M. De Pasquale (University of Messina), S. Dichiara\n(PSU), P. D’Avanzo (INAF-OAB), A. D’Aì (INAF-IASFPA) , V. D’Elia\n(ASI-SSDC & INAF-OAR), C. Gronwall (PSU), D. Hartmann (Clemson\nUniversity), N. Klingler (NASA-GSFC / UMBC / CRESST II), N.P.M. Kuin\n(UCL-MSSL), S. Laha (NASA/GSFC), S.R. Oates (U. Birmingham), J.P.\nOsborne (U. Leicester), P. O’Brien (U. Leicester), M.J. Page\n(UCL-MSSL), G. Raman (PSU) S. Ronchini (PSU), T. Sbarrato (INAF-OAB),\nB. Sbarufatti (INAF-OAB), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB),\nE. Troja (U Tor Vergata, INAF) report on behalf of the Swift team:\n\nSwift has carried out an extra 131 observations of the LVC error region\nfor the GW trigger S240615dg, re-observing the fields from our original\nsearch (Page et al., GCN Circ. 36698). None of the 39 X-ray sources\nreported previously show evidence for fading.\n\nWe have detected an additional 28 X-ray sources. Each source is\nassigned a rank of 1-4 which describes how likely it is to be related\nto the GW trigger, with 1 being the most likely and 4 being the least\nlikely. The ranks are described at https://www.swift.ac.uk/ranks.php.\n\nWe have found:\n\n  * 0 sources of rank 1\n  * 0 sources of rank 2\n  * 27 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| S240615dg_X40  | 00h 29m 11.77s | +46d 23' 08.6\" |\t7.0\" |\n| S240615dg_X41  | 00h 35m 07.98s | +46d 06' 59.0\" |\t5.7\" |\n| S240615dg_X42  | 00h 29m 37.71s | +45d 16' 24.8\" |\t6.1\" |\n| S240615dg_X43  | 00h 27m 15.43s | +46d 12' 40.0\" |\t8.1\" |\n| S240615dg_X44  | 00h 35m 13.49s | +46d 06' 05.6\" |\t5.7\" |\n| S240615dg_X46  | 00h 25m 16.37s | +45d 52' 02.5\" |\t9.4\" |\n| S240615dg_X47  | 00h 28m 17.21s | +44d 57' 16.8\" |\t8.5\" |\n| S240615dg_X48  | 00h 31m 20.40s | +46d 49' 39.9\" |\t9.7\" |\n| S240615dg_X49  | 00h 35m 35.80s | +46d 23' 49.6\" |\t6.2\" |\n| S240615dg_X50  | 00h 35m 29.05s | +46d 08' 42.8\" |   41.5\" |\n| S240615dg_X51  | 00h 25m 53.05s | +45d 34' 29.8\" |\t7.9\" |\n| S240615dg_X56  | 00h 25m 53.56s | +45d 29' 48.7\" |\t8.9\" |\n| S240615dg_X58  | 00h 31m 05.12s | +46d 33' 25.6\" |   13.3\" |\n| S240615dg_X59  | 00h 31m 08.24s | +46d 32' 10.8\" |\t8.1\" |\n| S240615dg_X60  | 00h 35m 42.54s | +45d 48' 05.6\" |\t5.7\" |\n| S240615dg_X61  | 00h 29m 30.69s | +46d 40' 25.7\" |\t8.2\" |\n| S240615dg_X62  | 00h 27m 01.17s | +46d 30' 12.4\" |\t7.2\" |\n| S240615dg_X63  | 00h 29m 41.77s | +46d 37' 51.5\" |\t8.2\" |\n| S240615dg_X64  | 00h 28m 43.62s | +45d 01' 49.1\" |\t5.6\" |\n| S240615dg_X65  | 00h 29m 28.36s | +46d 42' 15.1\" |   41.8\" |\n| S240615dg_X66  | 00h 33m 53.13s | +46d 45' 28.6\" |\t7.7\" |\n| S240615dg_X67  | 00h 33m 32.16s | +46d 08' 32.0\" |\t8.0\" |\n| S240615dg_X68  | 00h 25m 25.85s | +45d 33' 41.3\" |\t5.9\" |\n| S240615dg_X69  | 00h 32m 33.84s | +46d 47' 32.5\" |\t8.6\" |\n| S240615dg_X70  | 00h 28m 46.16s | +46d 05' 15.6\" |\t8.3\" |\n| S240615dg_X71  | 00h 28m 30.50s | +46d 19' 12.1\" |\t6.2\" |\n| S240615dg_X72  | 00h 28m 09.61s | +46d 18' 20.6\" |\t7.4\" |\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| S240615dg_X45  | 00h 35m 39.42s | +45d 48' 41.3\" |\t8.8\" |\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, unless otherwise\nstated.\n\nThe results of the XRT automated analysis, including details of the\nsources listed above, are online at\nhttps://www.swift.ac.uk/LVC/S240615dg\n\nThis circular is an official product of the Swift XRT team.\n\n\n",
  "submittedHow": "email",
  "subject": "LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources"
}