TITLE: GCN CIRCULAR NUMBER: 36226 SUBJECT: GRB 240415B: Swift-XRT observations DATE: 24/04/22 07:23:17 GMT FROM: Phil Evans at U of Leicester pae9@star.le.ac.uk
J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), D.N. Burrows (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 240415B, collecting 3.4 ks of Photon Counting (PC) mode data between T0+86.1 ks and T0+115.2 ks.
Four uncatalogued X-ray sources have been detected consistent with being within 493 arcsec of the Swift/BAT position, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below:
Source 2: RA (J2000.0): 132.2001 = 08:48:48.03 Dec (J2000.0): -27.0714 = -27:04:17.2 Error: 6.4 arcsec (radius, 90% conf.) Count-rate: (9.5 [+10.4, -8.3])e-4 ct s^-1 Distance: 374 arcsec from Swift/BAT position.
Source 3: RA (J2000.0): 132.3176 = 08:49:16.23 Dec (J2000.0): -27.1553 = -27:09:19.0 Error: 6.6 arcsec (radius, 90% conf.) Count-rate: (2.6 [+1.6, -1.3])e-3 ct s^-1 Distance: 306 arcsec from Swift/BAT position. Flux: (1.32 [+0.83, -0.68])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 6: RA (J2000.0): 132.3018 = 08:49:12.44 Dec (J2000.0): -27.1242 = -27:07:27.0 Error: 5.5 arcsec (radius, 90% conf.) Count-rate: (3.4 [+1.6, -1.3])e-3 ct s^-1 Distance: 200 arcsec from Swift/BAT position. Flux: (4.6 [+2.2, -1.8])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 7: RA (J2000.0): 132.4111 = 08:49:38.66 Dec (J2000.0): -27.0674 = -27:04:02.8 Error: 5.6 arcsec (radius, 90% conf.) Count-rate: (3.6 [+1.8, -1.5])e-3 ct s^-1 Distance: 301 arcsec from Swift/BAT position. Flux: (8.8 [+4.5, -3.6])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Three uncatalogued sources were also detected too far from the GRB position to be likely afterglow candidates.
The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021684.
This circular is an official product of the Swift-XRT team.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36226. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...