//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14717 SUBJECT: GRB 130529A: Swift detection of a burst DATE: 13/05/29 11:24:56 GMT FROM: Scott Barthelmy at NASA/GSFC V. D'Elia (ASDC), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), C. Pagani (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 11:15:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130529A (trigger=556930). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 24.259, -64.138, which is RA(J2000) = 01h 37m 02s Dec(J2000) = -64d 08' 17" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for image triggers, the real-time TDRSS lightcurve does not show anything significant. The XRT began observing the field at 11:17:18.0 UT, 112.6 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 24.2798, -64.1493 which is equivalent to: RA(J2000) = +01h 37m 7.15s Dec(J2000) = -64d 08' 57.5" with an uncertainty of 5.4 arcseconds (radius, 90% containment). This location is 52 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 1.24e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 122 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. Data from the list of sources generated on-board are not available at this time. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. 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: 14719 SUBJECT: GRB 130529A: Prompt enhanced Swift-XRT position DATE: 13/05/29 12:11:48 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 130529A, we find an enhanced XRT position of the afterglow: RA, Dec: 24.2820, -64.1473 which is equivalent to: RA (J2000) = 01 37 07.69 Dec (J2000) = -64 08 50.2 with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/556930. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14723 SUBJECT: GRB 130529A: Enhanced Swift-XRT position DATE: 13/05/29 22:58:28 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 7658 s of XRT Photon Counting mode data and 9 UVOT images for GRB 130529A, 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 = 24.28192, -64.14745 which is equivalent to: RA (J2000): 01h 37m 7.66s Dec (J2000): -64d 08' 50.8" with an uncertainty of 1.4 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: 14724 SUBJECT: GRB 130529A: Swift-XRT refined Analysis DATE: 13/05/29 23:25:03 GMT FROM: Phil Evans at U of Leicester B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), M.C. Stroh (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), G. Stratta (ASDC), P. D'Avanzo (INAF-OAB) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 8.6 ks of XRT data for GRB 130529A (D'Elia et al. GCN Circ. 14717), from 118 s to 19.2 ks after the BAT trigger. The data comprise 300 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 14719). The light curve can be modelled with an initial power-law decay with an index of alpha=1.67 (+/-0.04), followed by a break at T+1862 s to an alpha of 0.97 (+0.08, -0.14). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.36 (+0.08, -0.07). The best-fitting absorption column is 6.8 (+2.2, -2.0) x 10^20 cm^-2, in excess of the Galactic value of 2.7 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.32 (+0.15, -0.14) and a best-fitting absorption column of 6.9 (+4.5, -4.0) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.3 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.9 (+4.5, -4.0) x 10^20 cm^-2 Galactic foreground: 2.7 x 10^20 cm^-2 Excess significance: 1.7 sigma Photon index: 1.32 (+0.15, -0.14) If the light curve continues to decay with a power-law decay index of 0.97, the count rate at T+24 hours will be 8.1 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.3 x 10^-13 (4.7 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/00556930. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14726 SUBJECT: GRB 130529A: Swift-BAT refined analysis DATE: 13/05/30 11:00:33 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), E. E. Fenimore (LANL), N. Gehrels (GSFC), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+464 sec from recent telemetry downlinks, we report further analysis of BAT GRB 130529A (trigger #556930) (D'Elia, et al., GCN Circ. 14717). The BAT ground-calculated position is RA, Dec = 24.274, -64.143 deg, which is RA(J2000) = 01h 37m 05.7s Dec(J2000) = -64d 08' 34.8" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows the burst starting at ~T-20 sec, peaking at about T+80 sec, and ending at ~T+260 sec. T90 (15-350 keV) is 128 +- 35 sec (estimated error including systematics). The time-averaged spectrum from T-15.02 to T+150.62 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.56 +- 0.17. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+64.28 sec in the 15-150 keV band is 0.5 +- 0.1 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/556930/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14728 SUBJECT: GRB 130529A: Swift/UVOT Upper Limits DATE: 13/05/30 12:45:32 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130529A 123 s after the BAT trigger (D'Elia et al., GCN Circ. 14717). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 14723) 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) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 123 272 147 >21.6 u_FC 281 530 246 >20.8 white 123 7633 824 >22.1 v 611 12979 1237 >20.8 b 536 19245 1031 >21.1 u 281 18726 1641 >21.5 w1 660 17812 1415 >21.6 m2 635 13481 822 >21.0 w2 587 12064 1275 >21.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14730 SUBJECT: GRB 130529A: GROND upper limits DATE: 13/05/30 15:53:49 GMT FROM: Sylvio Klose at TLS Tautenburg K. Varela (MPE Garching), S. Klose, A. Nicuesa Guelbenzu (both TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field GRB 130529A (Swift trigger 556930; D' Elia et al., GCN 14717) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla Observatory (Chile). Observations started at 07:10 UT on May 30, about 20 hours after the trigger at a mean seeing of 1.7 arcsec and a mean airmass of 2. Inside the enhanced 1".4 XRT error circle (Osborne et al., GCN 14723), we do not detect any source. Based on an observation with 150 min integration time in g'r'i'z' and 124 min integration time in JHKs, we estimate preliminary 3-sigma upper limits (all in the AB system) of g' > 24.3, r' > 24.6, J > 21.8, H > 21.1. We note that the field is rich in galaxies. Within 10 arcsec around the XRT error circle are at least three objects (also visible on DSS2), with the most extended one an edge-on galaxy about 6" in diameter. The bad seeing prevents at the moment a more detailed classification of the other objects. Magnitudes are calibrated against GROND zero points (g'r'i'z') as well as 2MASS field stars (JHKs) and, as usual, are not corrected for Galactic extinction along the line of sight.