TITLE: GCN CIRCULAR NUMBER: 36837 SUBJECT: LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources DATE: 24/07/09 09:37:10 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> P.A. Evans (U. Leicester), K.L. Page (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), S.B. Cenko (NASA/GSFC), R.A.J. Eyles-Ferris (U. Leicester), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), S. Campana (INAF-OAB), J.J. Delaunay (PSU), M. De Pasquale (University of Messina), S. Dichiara (PSU), P. D’Avanzo (INAF-OAB), A. D’Aì (INAF-IASFPA) , V. D’Elia (ASI-SSDC & INAF-OAR), C. Gronwall (PSU), D. Hartmann (Clemson University), N. Klingler (NASA-GSFC / UMBC / CRESST II), N.P.M. Kuin (UCL-MSSL), S. Laha (NASA/GSFC), S.R. Oates (U. Birmingham), J.P. Osborne (U. Leicester), P. O’Brien (U. Leicester), M.J. Page (UCL-MSSL), G. Raman (PSU) S. Ronchini (PSU), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja (U Tor Vergata, INAF) report on behalf of the Swift team: Swift has carried out an extra 131 observations of the LVC error region for the GW trigger S240615dg, re-observing the fields from our original search (Page et al., GCN Circ. 36698). None of the 39 X-ray sources reported previously show evidence for fading. We have detected an additional 28 X-ray sources. Each source is assigned a rank of 1-4 which describes how likely it is to be related to the GW trigger, with 1 being the most likely and 4 being the least likely. The ranks are described at https://www.swift.ac.uk/ranks.php. We have found: * 0 sources of rank 1 * 0 sources of rank 2 * 27 sources of rank 3 * 1 source of rank 4 RANK 3 sources ============== These are uncatalogued X-ray sources, however they are not brighter than previous upper limits, so do not stand out as likely counterparts to the GW trigger. | Source ID | RA | Dec | Err90 | | S240615dg_X40 | 00h 29m 11.77s | +46d 23' 08.6" | 7.0" | | S240615dg_X41 | 00h 35m 07.98s | +46d 06' 59.0" | 5.7" | | S240615dg_X42 | 00h 29m 37.71s | +45d 16' 24.8" | 6.1" | | S240615dg_X43 | 00h 27m 15.43s | +46d 12' 40.0" | 8.1" | | S240615dg_X44 | 00h 35m 13.49s | +46d 06' 05.6" | 5.7" | | S240615dg_X46 | 00h 25m 16.37s | +45d 52' 02.5" | 9.4" | | S240615dg_X47 | 00h 28m 17.21s | +44d 57' 16.8" | 8.5" | | S240615dg_X48 | 00h 31m 20.40s | +46d 49' 39.9" | 9.7" | | S240615dg_X49 | 00h 35m 35.80s | +46d 23' 49.6" | 6.2" | | S240615dg_X50 | 00h 35m 29.05s | +46d 08' 42.8" | 41.5" | | S240615dg_X51 | 00h 25m 53.05s | +45d 34' 29.8" | 7.9" | | S240615dg_X56 | 00h 25m 53.56s | +45d 29' 48.7" | 8.9" | | S240615dg_X58 | 00h 31m 05.12s | +46d 33' 25.6" | 13.3" | | S240615dg_X59 | 00h 31m 08.24s | +46d 32' 10.8" | 8.1" | | S240615dg_X60 | 00h 35m 42.54s | +45d 48' 05.6" | 5.7" | | S240615dg_X61 | 00h 29m 30.69s | +46d 40' 25.7" | 8.2" | | S240615dg_X62 | 00h 27m 01.17s | +46d 30' 12.4" | 7.2" | | S240615dg_X63 | 00h 29m 41.77s | +46d 37' 51.5" | 8.2" | | S240615dg_X64 | 00h 28m 43.62s | +45d 01' 49.1" | 5.6" | | S240615dg_X65 | 00h 29m 28.36s | +46d 42' 15.1" | 41.8" | | S240615dg_X66 | 00h 33m 53.13s | +46d 45' 28.6" | 7.7" | | S240615dg_X67 | 00h 33m 32.16s | +46d 08' 32.0" | 8.0" | | S240615dg_X68 | 00h 25m 25.85s | +45d 33' 41.3" | 5.9" | | S240615dg_X69 | 00h 32m 33.84s | +46d 47' 32.5" | 8.6" | | S240615dg_X70 | 00h 28m 46.16s | +46d 05' 15.6" | 8.3" | | S240615dg_X71 | 00h 28m 30.50s | +46d 19' 12.1" | 6.2" | | S240615dg_X72 | 00h 28m 09.61s | +46d 18' 20.6" | 7.4" | RANK 4 sources ============== These are catalogued X-ray sources, showing no signs of outburst compared to previous observations, so they are not likely to be related to the GW trigger. | Source ID | RA | Dec | Err90 | | S240615dg_X45 | 00h 35m 39.42s | +45d 48' 41.3" | 8.8" | For all flux conversions and comparisons with catalogues and upper limits from other missions, we assumed a power-law spectrum with NH=3x10^20 cm^-2, and photon index (Gamma)=1.7, unless otherwise stated. The results of the XRT automated analysis, including details of the sources listed above, are online at https://www.swift.ac.uk/LVC/S240615dg This circular is an official product of the Swift XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/36837. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...