GRB120521A

This page lists all entries on GRB120521A in GRBweb

Summary IPN Swift GCN 13302 GCN 13303 GCN 13304 GCN 13310 GCN 13312 GCN 13326 GCN 13327 GCN 13335 GCN 13338

Summary table
Variable Value Source
T0 5:59:42 UTC GCN_circulars,Swift Det
ra 148.7246° Swift
decl -49.4173° Swift
pos_error 2.33e-04° Swift
T90 0.45 s Swift
T90_start 5:59:42 UTC Swift
fluence 7.80e-08 erg/cm² Swift
T100 0.45 s
GBM_located False
mjd 56068.24979166667 GCN_circulars,Swift Det
IPN table
GRB_name GRB120521A
ra 148.6917°
decl -49.4167°
pos_error 5.00e-02°
Swift table
GRB_name GRB120521A
t_trigger 5:59:42 UTC
ra 148.7246°
decl -49.4173°
pos_error 2.33e-04°
T90 0.45 s
fluence 7.80e-08 erg/cm²
GCN 13302 table
GRB_name GRB120521A
GCN_number 13302
Detection_method Swift Det
t_trigger 5:59:42 UTC
ra 148.6930°
decl -49.4190°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13302 SUBJECT: GRB 120521A: Swift detection of a short burst DATE: 12/05/21 06:12:55 GMT FROM: David Palmer at LANL M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC), B. Gendre (ASDC), D. M. Palmer (LANL) and G. Stratta (ASDC) report on behalf of the Swift Team: At 05:59:42 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120521A (trigger=522578). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 148.693, -49.419 which is RA(J2000) = 09h 54m 46s Dec(J2000) = -49d 25' 08" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single short FRED structure with a duration of about 0.7 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0.25 sec after the trigger. The XRT began observing the field at 06:00:56.6 UT, 73.8 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 148.72544, -49.41760 which is equivalent to: RA(J2000) = 09h 54m 54.11s Dec(J2000) = -49d 25' 03.4" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 76 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.08 x 10^21 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 150 seconds with the White filter starting 77 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. 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 large, but uncertain extinction expected.
GCN 13303 table
GRB_name GRB120521A
GCN_number 13303
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 13303 SUBJECT: GRB 120521A: TAROT La Silla observatory optical observations DATE: 12/05/21 06:34:10 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 120521A detected by SWIFT (trigger 522578) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. The observations started 35.2s after the GRB trigger (15.1s after the notice). The elevation of the field decreased from 10 degrees above horizon and weather conditions were good. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any OT in the XRT position (Chester et al. GCNC 13302) with a limiting magnitude of: t0+35.2s to t0+95.2s : R > 15.8 The second image is 30.0s exposure in tracking mode: t0+108.9s to t0+138.9s : R > 16.5 We co-added a series of exposures: t0+109s to t0+533s : R > 17.4 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
GCN 13304 table
GRB_name GRB120521A
GCN_number 13304
Detection_method Swift-XRT Det
ra 148.7246°
decl -49.4173°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13304 SUBJECT: GRB 120521A: Enhanced Swift-XRT position DATE: 12/05/21 09:01:33 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 508 s of XRT Photon Counting mode data and 1 UVOT images for GRB 120521A, 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 = 148.72462, -49.41733 which is equivalent to: RA (J2000): 09h 54m 53.91s Dec (J2000): -49d 25' 02.4" with an uncertainty of 1.9 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.
GCN 13310 table
GRB_name GRB120521A
GCN_number 13310
Detection_method Swift-BAT Det
ra 148.6920°
decl -49.4220°
Circular_text TITLE: GCN CIRCULAR NUMBER: 13310 SUBJECT: GRB 120521A: Swift-BAT refined analysis DATE: 12/05/21 11:37:22 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), 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+363 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120521A (trigger #522578) (Chester, et al., GCN Circ. 13302). The BAT ground-calculated position is RA, Dec = 148.692, -49.422 deg, which is RA(J2000) = 09h 54m 46.1s Dec(J2000) = -49d 25' 17.8" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows FRED pulse starting at ~T+0.0, peaking at ~T+0.1, and ending at ~T+1.0 sec. T90 (15-350 keV) is 0.45 +- 0.08 sec (estimated error including systematics). The time-averaged spectrum from T+0.02 to T+0.56 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.98 +- 0.22. The fluence in the 15-150 keV band is 7.8 +- 1.1 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.21 sec in the 15-150 keV band is 0.9 +- 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/522578/BA/
GCN 13312 table
GRB_name GRB120521A
GCN_number 13312
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 13312 SUBJECT: GRB 120521A: Swift/UVOT Upper Limits DATE: 12/05/21 14:05:01 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and M. M. Chester (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 120521A 77 s after the BAT trigger (Chester et al., GCN Circ. 13302). No optical afterglow consistent with the XRT position (Goad et al., GCN Circ. 13304) 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 77 227 147 >21.4 u_FC 289 539 246 >20.9 white 77 5491 363 >21.9 v 4266 5901 393 >19.7 b 545 11343 766 >21.9 u 289 10775 1386 >21.6 w1 4676 6312 393 >20.4 m2 4470 6106 393 >20.6 w2 4061 5697 393 >20.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.43 in the direction of the burst (Schlegel et al. 1998).
GCN 13326 table
GRB_name GRB120521A
GCN_number 13326
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 13326 SUBJECT: GRB 120521A: Swift-XRT refined Analysis DATE: 12/05/22 07:15:00 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA) and M.M. Chester report on behalf of the Swift-XRT team: We have analysed 4.3 ks of XRT data for GRB 120521A (Chester et al. GCN Circ. 13302), from 83 s to 11.3 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 13304). The light curve can be modelled with a power-law decay with a decay index of alpha=anf (+/anf). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.81 (+0.36, -0.29). The best-fitting absorption column is 2.6 (+1.4, -0.5) x 10^21 cm^-2, consistent with the Galactic value of 2.1 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (6.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.6 (+1.4, -0.5) x 10^21 cm^-2 Galactic foreground: 2.1 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.81 (+0.36, -0.29) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00522578. This circular is an official product of the Swift-XRT team.
GCN 13327 table
GRB_name GRB120521A
GCN_number 13327
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 13327 SUBJECT: GRB 120521A: XRT light curve (Correction to GCN 13326) DATE: 12/05/22 07:22:33 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: There was an error in GCN 13326: the light curve decay slope was reported as infinity. The XRT light curve in fact shows a plateau (alpha=0.2 +/-0.4) until T0+270 seconds. After this it undergoes an extremely sharp decay (alpha~10) and is not detected in X-rays after T0+1ks.
GCN 13335 table
GRB_name GRB120521A
GCN_number 13335
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 13335 SUBJECT: GRB 120521A: GROND Upper limits DATE: 12/05/22 17:11:33 GMT FROM: Andrea Rossi at TLS Tautenburg A. Rossi (TLS Tautenburg), M. Nardini (Universita' degli Studi Milano-Bicocca), S. Klose (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 120521A (Swift trigger 522578; Chester et al., GCN 13302) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile). Observations started at 22:53 UT on 2012-05-21, 16.9 h after the GRB trigger, and lasted for 100 minutes. They were performed under good sky conditions at an average seeing of 0.9 and at an average airmass of 1.1. Using an exposure of 50 minutes in the optical and 40 minutes in the NIR we do not detect any source within the Swift-XRT error circle reported by Goad et al. (GCN 13304). Preliminary observed upper limits (AB mags) are: g' > 25.5 r' > 25.0 i' > 24.0 z' > 23.7 J > 20.9 H > 20.3 K > 19.1 The given limits are derived based on calibrating the images against GROND zeropoints (g'r'i'z') and 2MASS stars (JHK). We note that the Galactic reddening along the line of sight is E_(B-V)= 0.43 mag (Schlegel et al. 1998).
GCN 13338 table
GRB_name GRB120521A
GCN_number 13338
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 13338 SUBJECT: GRB 120521A: ATCA 34GHz upper limit DATE: 12/05/23 01:44:01 GMT FROM: Paul Hancock at U of Sydney P. Hancock, T. Murphy, B. Gaensler, M. Bell, D. Burlon (University of Sydney/CAASTRO), A. de Ugarte Postigo (Dark Cosmology / IAA) We observed GRB120521A (GCN13302) with the Australia Telescope Compact Array at 34GHz for 112 mins centered on 07:55UT May 22 2012 (T0+1.08days). We detect no radio source at the location of the GRB (GCN13304) and place a 3sigma upper limit of 95uJy on the flux of an afterglow. These observations were obtained as part of ATCA project C2689. We thank the observatory staff for their support and scheduling the observations. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.