//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16450 SUBJECT: GRB 140623A / iPTF14cyb: Fermi GBM detection DATE: 14/06/24 14:58:54 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 05:22:06.60 UT on 23 June 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140623A (trigger 425193729 / 140623224), which was observed by the intermediate Palomar Transient Factory beginning 11 minutes after trigger time, and was reported in GCN 16425 (Bhalerao et al. 2014) as iPTF14cvb. The on-ground calculated location, using the GBM trigger data, is RA = 202.8, DEC = 75.8 (J2000 degrees, equivalent to 13h 31m, 75d 48'), with an uncertainty of 5.6 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 32 degrees. The GBM light curve shows a multiple-peak structure with a duration (T90) of about 110 s (50-300 keV). The time-averaged spectrum from T0-49.2 s to T0+73.7 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.46 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 350(+220/-100) keV The event fluence (10-1000 keV) in this time interval is (6.8 +/- 0.6)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0-3.65 s in the 10-1000 keV band is 1.9 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16451 SUBJECT: GRB 140623A: Swift-XRT and UVOT observations DATE: 14/06/24 15:21:15 GMT FROM: Valerio D'Elia at ASDC V. D'Elia (ASDC), F. E. Marshall (NASA/GSFC), L. Izzo (URoma/ICRA) & D. Malesani (DARK/NBI) report on behalf of the Swift team: Following the report of a potential optical afterglow iPTF14cyb (Bhalerao et al., GCN Circ. 16442) to the Fermi/GBM-detected burst GRB 140623A (von Kienlin, GCN Circ. 16450), Swift began a follow-up observation of the iPTF field. We have analyzed all the 3.0 ks of XRT data for GRB 140623A, from 38.7 ks to 49.6 ks after the Fermi/GBM trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is detected at a position consistent with the candidate optical afterglow (Bhalerao et al., GCN Circ. 16442) within the Fermi/GBM error circle. Using 1153 s of PC mode data and 1 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 225.47927, +81.19049 which is equivalent to: RA (J2000): 15h 01m 55.02s Dec(J2000): +81d 11' 25.7" with an uncertainty of 5.8 arcsec (radius, 90% confidence). This position is 5.0 arcsec from the the optical counterpart iPTF14cyb, and consistent with it. We cannot determine at the present time whether the source is fading. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020388. The Swift/UVOT began settled observations of the field of GRB 140423A 38708 s after the GBM trigger. No optical afterglow consistent with the optical position (Bhalerao et al. GCN Circ. 16442) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are: Filter T_start(s) T_stop(s) Exp(s) Mag u 38708 44173 925 >22.0 white 38926 44863 851 >21.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.037 in the direction of the burst (Schlegel et al. 1998). This circular is an official product of the Swift team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16464 SUBJECT: GRB 140623A: further Swift-XRT observations DATE: 14/06/27 13:41:23 GMT FROM: Valerio D'Elia at ASDC V. D'Elia (ASDC), L. Izzo (URoma/ICRA) report on behalf of the Swift-XRT team: We report further Swift-XRT observations of GRB 140623A (A. von Kienlin, GCN Circ 16450; Bhalerao et al., GCN Circ. 16442). A new exposure of 5 ks has been secured 285 ks after the Fermi/GBM detection. The X-ray counterpart detected by D'Elia et al. (GCN Circ. 16451) is no longer present down to a three sigma upper limit of 2.2E-3 cts/s. We thus conclude that the source reported in D'Elia et al. (GCN Circ. 16451) is the X-ray afterglow of GRB 140623A. This circular is an official product of the Swift-XRT team.