//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16097 SUBJECT: GRB 140412A: Swift detection of a burst DATE: 14/04/12 22:33:10 GMT FROM: David Burrows at PSU/Swift V. D'Elia (ASDC), D. N. Burrows (PSU), S. T. Holland (STScI), L. Izzo (URoma/ICRA), F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 22:20:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140412A (trigger=595608). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 145.050, -65.809 which is RA(J2000) = 09h 40m 12s Dec(J2000) = -65d 48' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED-like structure with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 22:24:17.0 UT, 207.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 144.9713, -65.8226 which is equivalent to: RA(J2000) = 09h 39m 53.11s Dec(J2000) = -65d 49' 21.3" with an uncertainty of 3.2 arcseconds (radius, 90% containment). This location is 125 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. No spectrum from the promptly downlinked event data is yet available to determine the column density. UVOT took a finding chart exposure of 150 seconds with the White filter starting 236 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.22. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16100 SUBJECT: GRB 140412A: Enhanced Swift-XRT position DATE: 14/04/13 04:13:35 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 862 s of XRT Photon Counting mode data and 1 UVOT images for GRB 140412A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 144.97315, -65.82169 which is equivalent to: RA (J2000): 09h 39m 53.55s Dec (J2000): -65d 49' 18.1" with an uncertainty of 2.1 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16103 SUBJECT: GRB 140412A: Swift-BAT refined analysis DATE: 14/04/13 14:22:16 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 140412A (trigger #595608) (D'Elia, et al., GCN Circ. 16097). The BAT ground-calculated position is RA, Dec = 145.032, -65.826 deg, which is RA(J2000) = 09h 40m 07.6s Dec(J2000) = -65d 49' 33.7" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The mask-weighted light curve shows two peaks strting at ~T-35 sec, peaking at ~T+1 sec, and ending at ~T+35 sec. T90 (15-350 keV) is 39.6 +- 8.2 sec (estimated error including systematics). The time-averaged spectrum from T-36.94 to T+12.18 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.95 +- 0.19. The fluence in the 15-150 keV band is 7.2 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.04 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/595608/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16104 SUBJECT: GRB 140412A: Swift-XRT refined Analysis DATE: 14/04/13 15:33:04 GMT FROM: Phil Evans at U of Leicester V. Mangano (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 140412A (D'Elia et al. GCN Circ. 16097), from 198 s to 41.3 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 16100). The light curve can be modelled with a power-law decay with a decay index of alpha=0.60 (+0.10, -0.09). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 3.2 (+0.9, -0.6). The best-fitting absorption column is 9.1 (+4.6, -3.3) x 10^21 cm^-2, in excess of the Galactic value of 2.6 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.8 x 10^-11 (1.7 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 9.1 (+4.6, -3.3) x 10^21 cm^-2 Galactic foreground: 2.6 x 10^21 cm^-2 Excess significance: 3.3 sigma Photon index: 3.2 (+0.9, -0.6) If the light curve continues to decay with a power-law decay index of 0.60, the count rate at T+24 hours will be 3.7 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x 10^-13 (6.4 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00595608. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16108 SUBJECT: GRB 140412A: Swift/UVOT Upper Limits DATE: 14/04/14 12:46:51 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: Swift/UVOT began settled observations of the field of GRB 140412A 237 s after the BAT trigger (D'Elia et al. 2014, GCNC 16097). We do not detect any new source consistent with the UVOT-enhanced XRT afterglow position (Goad et al. 2014, GCNC 16100) in any of the UVOT exposures. Preliminary 3-sigma upper limits, using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373), for the finding chart and summed exposures are presented below. --------------------------------------------------- Filter TSTART TSTOP Exposure Mag --------------------------------------------------- v 393 1055 69 >19.0 b 491 6805 255 >21.0 u 466 6599 309 >20.6 uvw1 442 4815 255 >20.0 uvm2 418 4610 255 >19.6 uvw2 541 1040 58 >18.7 white 237 6811 336 >21.8 --------------------------------------------------- The quoted upper limits have not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 0.19 mag (Schlafly et al. 2011, ApJS, 737, 103).