GRB111020A

This page lists all entries on GRB111020A in GRBweb

Summary IPN Swift GCN 12460 GCN 12461 GCN 12462 GCN 12463 GCN 12464 GCN 12465 GCN 12466 GCN 12467 GCN 12468 GCN 12469 GCN 12470 GCN 12477 GCN 12492 GCN 12739

Summary table
Variable Value Source
T0 6:33:49 UTC GCN_circulars,Swift Det
ra 287.0523° Swift
decl -38.0122° Swift
pos_error 2.07e-04° Swift
T90 0.4 s Swift
T90_start 6:33:49 UTC Swift
fluence 6.50e-08 erg/cm² Swift
T100 0.4 s
GBM_located False
mjd 55854.2734837963 GCN_circulars,Swift Det
IPN table
GRB_name GRB111020A
ra 287.0250°
decl -37.9833°
pos_error 5.00e-02°
Swift table
GRB_name GRB111020A
t_trigger 6:33:49 UTC
ra 287.0523°
decl -38.0122°
pos_error 2.07e-04°
T90 0.4 s
fluence 6.50e-08 erg/cm²
GCN 12460 table
GRB_name GRB111020A
GCN_number 12460
Detection_method Swift Det
t_trigger 6:33:49 UTC
ra 287.0270°
decl -37.9850°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12460 SUBJECT: GRB 111020A: Swift detection of a short burst DATE: 11/10/20 06:46:03 GMT FROM: David Palmer at LANL T. Sakamoto (NASA/UMBC), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), C. Guidorzi (U Ferrara), V. Mangano (INAF-IASFPA), K. L. Page (U Leicester), D. M. Palmer (LANL) and P. Romano (INAF-IASFPA) report on behalf of the Swift Team: At 06:33:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 111020A (trigger=505926). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 287.027, -37.985 which is RA(J2000) = 19h 08m 06s Dec(J2000) = -37d 59' 05" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a short single peak structure with a duration of about 0.5 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 06:35:01.8 UT, 72.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 287.05305, -38.01178 which is equivalent to: RA(J2000) = 19h 08m 12.73s Dec(J2000) = -38d 00' 42.4" with an uncertainty of 4.1 arcseconds (radius, 90% containment). This location is 121 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 6.89 x 10^20 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 150 seconds with the White filter starting 79 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 0.43. Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT nasa.gov). 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.)
GCN 12461 table
GRB_name GRB111020A
GCN_number 12461
Detection_method Other
ra 287.0530°
decl -38.0118°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12461 SUBJECT: GRB 111020A: Planned XMM-Newton observation DATE: 11/10/20 08:10:40 GMT FROM: Norbert Schartel at XMM-Newton/ESA XMM-Newton will observe GRB 111020A at location (RA=19h 08m 12.73s, DEC=-38d 00' 42.4", J2000), starting at 19:41:49 UT, on October 20, 2011, for an exposure of 30,000 seconds. ================================================================================================ This message and any attachments are intended for the use of the addressee or addressees only. The unauthorised disclosure, use, dissemination or copying (either in whole or in part) of its content is not permitted. If you received this message in error, please notify the sender and delete it from your system. Emails can be altered and their integrity cannot be guaranteed by the sender. Please consider the environment before printing this email. =================================================================================================
GCN 12462 table
GRB_name GRB111020A
GCN_number 12462
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 12462 SUBJECT: GRB 111020A: BOOTES-3 Optical Upper Limit. DATE: 11/10/20 15:07:24 GMT FROM: Juan Carlos Tello at IAA-CSIC J. C. Tello (IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), A. J. Castro-Tirado, J. Gorosabel (IAA-CSIC), on behalf of a larger collaboration, report: We have observed the field of the short GRB 111020A, detected by Swift/BAT (Palmer et al., GCNC 12460) with the 0.6m Yock-Allen telescope at the BOOTES-3 station in Blenheim (New Zealand). Unfiltered images were obtained starting 69.72 minutes after the burst (07:43:32 UT), no new source is visible in the co-added image with total exposure 6900 sec (115 images ending in 09:40:53 UT), the limiting magnitude for the combined image is R = 19.5 (calibrated against USNO B1.0). USNO B1-0519-0893471, a catalogued R=18.7 magnitude source is at the edge of the XRT circle but shows no evident variability.
GCN 12463 table
GRB_name GRB111020A
GCN_number 12463
Detection_method Swift-XRT Det
ra 287.0522°
decl -38.0122°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12463 SUBJECT: GRB 111020A: Enhanced Swift-XRT position DATE: 11/10/20 15:32:42 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 2124 s of XRT Photon Counting mode data and 3 UVOT images for GRB 111020A, 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 = 287.05219, -38.01216 which is equivalent to: RA (J2000): 19h 08m 12.53s Dec (J2000): -38d 00' 43.8" with an uncertainty of 1.6 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 12464 table
GRB_name GRB111020A
GCN_number 12464
Detection_method Swift-BAT Det
ra 287.0290°
decl -38.0310°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12464 SUBJECT: GRB 111020A: Swift-BAT refined analysis DATE: 11/10/20 15:49:32 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), 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-240 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 111020A (trigger #505926) (Sakamoto, et al., GCN Circ. 12460). The BAT ground-calculated position is RA, Dec = 287.029, -38.031 deg, which is RA(J2000) = 19h 08m 06.9s Dec(J2000) = -38d 01' 50.3" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 74%. The mask-weighted light curve shows a single spike starting at ~T+0.0, peaking at ~T+0.1 sec, and ending at ~T+1.0 sec. There is a hint (at the 2.5-sigma level) of a soft tail out to ~T+10 sec. T90 (15-350 keV) is 0.40 +- 0.09 sec (estimated error including systematics). The time-averaged spectrum from T-0.04 to T+0.39 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.37 +- 0.26. The fluence in the 15-150 keV band is 6.5 +- 1.0 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.32 sec in the 15-150 keV band is 0.9 +- 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/505926/BA/
GCN 12465 table
GRB_name GRB111020A
GCN_number 12465
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12465 SUBJECT: GRB 111020A: Faulkes Telescope South observations DATE: 11/10/20 16:07:13 GMT FROM: Nial Tanvir at U.Leicester C. Guidorzi (U. Ferrera), N. R. Tanvir (U. Leicester), C. Mottram, D. Bersier (Liverpool JMU), report: On 2011 October 20 at 11:02:37 UT the 2-m Faulkes Telescope South began observing short GRB 111020A (Sakamoto et al., GCN Circ. 12460) using the Ri filters, corresponding to approximately 4.5 hours after the burst trigger time. We detect no uncatalogued sources, either inside or near the enhanced XRT error circle (Osborne et al. GCN Circ. 12463), to the following limiting magnitudes: Mid time from Total Exp Filter Magnitude trigger (hours) (s) ------------------------------------------------ 4.75 6x300 R> 21.0 5.32 6x300 i> 21.7 ------------------------------------------------ Magnitudes have been calibrated from nearby USNOB-1 stars using their R2 and I nominal values.
GCN 12466 table
GRB_name GRB111020A
GCN_number 12466
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12466 SUBJECT: GRB 111020A: Swift/UVOT Upper Limits DATE: 11/10/20 19:47:57 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 111020A 80 s after the BAT trigger (Sakamoto et al., GCN Circ. 12460). No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ. 12463) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 80 230 147 >20.0 u_FC 292 542 246 >19.6 white 80 7160 766 >20.3 v 622 6135 275 >18.8 b 547 6956 471 >19.9 u 292 18728 1973 >20.3 w1 670 18066 2242 >21.0 m2 6140 22385 2310 >21.1 w2 1027 5930 216 >20.5 This photometry may be complicated by the presence of a catalogued source approximately 3'' away from the centre of the enhanced XRT error circle. 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 12467 table
GRB_name GRB111020A
GCN_number 12467
Detection_method Other
ra 287.0521°
decl -38.0116°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12467 SUBJECT: GRB 111020A: Gemini-South i-band observations DATE: 11/10/21 01:58:38 GMT FROM: Wen-fai Fong at CFA W. Fong (Harvard), E. Berger (Harvard) and D. Fox (PSU) report: We imaged the location of the short GRB 111020A (GCN 12460) with GMOS on the Gemini-South 8-m telescope on 2011 October 21.01 UT (mid-time of 17.7 hours post-burst). We obtained 9x180s exposures in i-band with 0.8" seeing. We find no sources within the enhanced XRT error circle (GCN 12463) to a 3-sigma limiting magnitude of i~25 mag. However, we find two faint objects just outside of the XRT error circle with coordinates (J2000): S1: RA = 19:08:12.501 Dec = -38:00:41.80 S2: RA = 19:08:12.698 Dec = -38:00:44.46 S1 has a brightness of i~23.7 mag and appears to be point-like. S2 is fainter, at the threshold of detectability with a brightness of i~25 mag. The nearest galaxy is located at: G1: RA = 19:08:12.231 Dec = -38:00:48.80 with a magnitude of i~23.3 mag, and 6.2" from the center of the XRT error circle.
GCN 12468 table
GRB_name GRB111020A
GCN_number 12468
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12468 SUBJECT: GRB 111020A: Swift-XRT refined Analysis DATE: 11/10/21 07:36:44 GMT FROM: Vanessa Mangano at INAF-IASFPA V. Mangano (INAF IASFPA) and T. Sakamoto (NASA/UMBC) reports on behalf of the Swift-XRT team: We have analysed 20 ks of XRT data for GRB 111020A (Sakamoto et al. GCN Circ. 12460), from 59 s to 69.8 ks after the BAT trigger. The data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 12463). The light curve can be modelled with a power-law decay with a decay index of alpha=0.72 (+/-0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.14 (+0.19, -0.41). The best-fitting absorption column is 10.0 (+5.4, -1.8) x 10^21 cm^-2, in excess of the Galactic value of 6.9 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.3 x 10^-11 (1.2 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 10.0 (+5.4, -1.8) x 10^21 cm^-2 Galactic foreground: 6.9 x 10^20 cm^-2 Excess significance: 8.9 sigma Photon index: 2.14 (+0.19, -0.41) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00505926. This circular is an official product of the Swift-XRT team.
GCN 12469 table
GRB_name GRB111020A
GCN_number 12469
Detection_method VLA Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 12469 SUBJECT: GRB 111020A: EVLA observations DATE: 11/10/21 14:26:47 GMT FROM: Wen-fai Fong at CFA W. Fong, A. Zauderer and E. Berger (Harvard) report: "We observed the position of GRB 111020A (GCN 12460) with the EVLA beginning on 2011 October 20.98 UT (16.9 hours post-burst) at a mean frequency of 5.8 GHz. In 1 hour of observations we do not detect any radio source within the enhanced XRT error circle (GCN 12463) to a 3-sigma limit of ~50 microJy. Further observations are in progress."
GCN 12470 table
GRB_name GRB111020A
GCN_number 12470
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 12470 SUBJECT: GRB 111020A: Gemini-South additional observations and limit on an optical afterglow DATE: 11/10/22 02:47:44 GMT FROM: Wen-fai Fong at CFA W. Fong and E. Berger (Harvard) report: "We re-imaged the field of GRB 111020A (GCN 12640) with GMOS on the Gemini-South telescope on 2011 October 22.01 UT (mid-time of 1.7 days post-burst, and 23.1 hours after our initial observations; GCN 12467). We obtained 11x180s exposures in i-band in 0.73" seeing. We still detect the two faint sources S1 and S2 from our previous GMOS observation (GCN 12467), and neither source shows evidence for fading. Digital image subtraction of the two epochs using the ISIS package reveals no residuals inside or near the XRT error circle. We therefore place a limit on the optical afterglow of i~25 mag at 17.7 hours after the burst."
GCN 12477 table
GRB_name GRB111020A
GCN_number 12477
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 12477 SUBJECT: GRB 111020A Spectral lag analysis DATE: 11/10/22 20:25:56 GMT FROM: Takanori Sakamoto at NASA/GSFC T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), J. Norris (BSU), T. N. Ukwatta (MSU) We report the spectral lag analysis for GRB 111020A (GCN Circ. 12460) based on the BAT data. Using 64 ms binned light curves, the spectral lag for 15-25 keV to 50-100 keV is 124 +36/-38 msec. This significant lag is due to a broader pulse in the 15-25 keV band comparing to that in the 50-100 keV band which indicates the strong pulse evolution from hard to soft. Although the burst duration itself is short (T90 = 400 ms; GCN Circ. 12464), this positive lag argues against a "short" classification. However, there is a possibility that the broader pulse seen in the 15-25 keV band is composed from two pulses instead of a single pulse. If this is the case, the lag result above could be confused by cross-correlating the 2nd pulse in the 15-25 keV and the 1st pulse in the 50-100 keV band. Due to the limiting signal-to-noise in the light curve data, it is not possible to claim whether the broad pulse in the 15-25 keV has two pulses or just a single pulse. Give the large non-zero lag and the possible double peak interpretation that could cause a false lag, we think it equally like that this burst is short or long. [GCN OPS NOTE(24oct11): Per author's request, the T90 value typo was corrected to 400 ms.]
GCN 12492 table
GRB_name GRB111020A
GCN_number 12492
Detection_method correction
ra 287.0521°
decl -38.0118°
Circular_text TITLE: GCN CIRCULAR NUMBER: 12492 SUBJECT: GRB 111020A: Chandra Observation DATE: 11/10/24 20:28:14 GMT FROM: Edo Berger at Harvard E. Berger, R. Margutti, and W. Fong (Harvard) report: "We observed the field of the short GRB 111020A (GCN 12640) with the Chandra X-ray Observatory + ACIS-S starting on 2011 October 23.14 UT (2.86 days after the burst) for a total of 19.8 ksec. We clearly detect a source in coincidence with the enhanced XRT error circle (GCN 12463) at the following coordinates (J2000): RA = 19:08:12.502 DEC = -38:00:42.58 with an uncertainty of about 0.5". The position includes a minor correction to the Chandra astrometry using two X-ray sources with stellar counterparts in our Gemini i-band images (which were astrometrically matched to the 2MASS catalog; GCNs 12467, 12470). The Chandra position is offset by 1.2" from the centroid of the most recent XRT position (which has a 90% containment uncertainty of 1.6"). Further analysis of the Chandra data is on-going. We thank Harvey Tananbaum and the CXO scheduling staff for rapidly approving and executing this observation."
GCN 12739 table
GRB_name GRB111020A
GCN_number 12739
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12739 SUBJECT: XMM-Newton observation of the short GRB 111020A DATE: 11/12/28 16:55:48 GMT FROM: Sergio Campana at INAF-OAB S. Campana (INAF-Osservatorio astronomico di Brera) reports: XMM-Newton observed the short GRB 111020A (Sakamoto et al. 2011, GCN 12460) on Oct 20, 2011 21:50:05 UT (15.3 hr after the burst onset). The ~20 ks observation was affected in the first part by a mild enhanced background event which we filtered out. The resulting pn/MOS1/MOS2 exposure times were 15, 17 and 17 ks, respectively. A source is well detected at a position consistent with the Swift's (Osborne et al. 2011, GCN 12463) and Chandra's (Berger et al. 2011, GCN 12492) ones. The pn count rate is (2.2+/-0.2)x10^{-2} cts/s. We extracted 422, 166, and 142 source photons from the pn, MOS1, and MOS2, respectively. The spectrum can be fitted with a power law model including a non-negligible absorption component in addition to the Galactic one (6.9x10^{20} cm^{-2}). The best fit power law implies a photon index of Gamma=1.9+/-0.3 (90% c.l. for one parameter of interest) and an additional column density of NH=(6+/-2)x10^{21} cm^{-2} (90% c.l.). This provides a lower limit to the intrinsic column density. The reduced chi^2 of the fit is 0.83 (31 d.o.f.). The unabsorbed 0.5-10 keV is ~2x10^{-13} erg/cm^2/s.