//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21321 SUBJECT: GRB 170711A: Swift detection of a burst DATE: 17/07/11 22:32:34 GMT FROM: David Palmer at LANL V. D'Elia (ASDC), D. N. Burrows (PSU), A. Cholden-Brown (PSU), A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF/USRA), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 22:20:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170711A (trigger=761622). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 45.786, +47.850 which is RA(J2000) = 03h 03m 09s Dec(J2000) = +47d 51' 01" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Due to a data gap, the BAT light curve is currently available only until 8 seconds after the trigger. The available BAT lightcurve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 22:21:28.7 UT, 63.4 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 45.79854, 47.84896 which is equivalent to: RA(J2000) = 03h 03m 11.65s Dec(J2000) = +47d 50' 56.3" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 30 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 3.23 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 250 seconds with the U filter starting 123 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 19.2 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 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.31. 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: 21322 SUBJECT: GRB 170711A: Prompt enhanced Swift-XRT position DATE: 17/07/11 22:59:31 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 170711A, we find an enhanced XRT position of the afterglow: RA, Dec: 45.8014, 47.8489 which is equivalent to: RA (J2000) = 03 03 12.33 Dec (J2000) = +47 50 55.9 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/761622. 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: 21323 SUBJECT: GRB 170711A: Enhanced Swift-XRT position DATE: 17/07/12 00:32:59 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 1474 s of XRT Photon Counting mode data and 2 UVOT images for GRB 170711A, 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 = 45.80093, +47.84897 which is equivalent to: RA (J2000): 03h 03m 12.22s Dec (J2000): +47d 50' 56.3" with an uncertainty of 2.3 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: 21324 SUBJECT: GRB 170711A: Fermi GBM observation DATE: 17/07/12 03:21:47 GMT FROM: Rachel Hamburg at UAH R. Hamburg (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 22:20:25.30 UT on 11 July 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170711A (trigger 521504430 / 170711931) which was also detected by the Swift/BAT (V. D'Elia et al. 2017, GCN 21321) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 32 degrees. The GBM light curve shows one spike with a duration (T90) of about 12 s (50-300 keV). The time-averaged spectrum from T0-2.6 s to T0+10.8 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.5 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 155 +/- 34 keV. The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.3 s in the 10-1000 keV band is 7.2 +/- 0.3 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: 21325 SUBJECT: GRB 170711A: Swift-XRT refined Analysis DATE: 17/07/12 03:58:36 GMT FROM: Phil Evans at U of Leicester A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 170711A (D'Elia et al. GCN Circ. 21321), from 51 s to 13.0 ks after the BAT trigger. The data comprise 6 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 Beardmore et al. (GCN Circ. 21322). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=3.2 (+0.8, -0.7). At T+160 s the decay flattens to an alpha of -0.14 (+0.25, -0.65) before breaking again at T+1004 s to a final decay with index alpha=0.59 (+0.36, -0.11). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.08 (+0.22, -0.21). The best-fitting absorption column is 6.7 (+1.5, -1.3) x 10^21 cm^-2, in excess of the Galactic value of 3.2 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 4.2 x 10^-11 (7.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.7 (+1.5, -1.3) x 10^21 cm^-2 Galactic foreground: 3.2 x 10^21 cm^-2 Excess significance: 4.2 sigma Photon index: 2.08 (+0.22, -0.21) If the light curve continues to decay with a power-law decay index of 0.59, the count rate at T+24 hours will be 0.018 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.7 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00761622. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21328 SUBJECT: GRB 170711A: RATIR Optical and NIR Observations DATE: 17/07/12 15:32:17 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 170711A (D'Elia, et al., GCN 21321) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2017/07 12.46 to 2017/07 12.48 UTC (12.68 to 13.13 hours after the BAT trigger), obtaining a total of 0.33 hours exposure in the r and i bands and 0.14 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Beardmore, et al., GCN 21323), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 22.94 i > 22.86 Z > 21.61 Y > 21.45 J > 21.08 H > 20.83 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21329 SUBJECT: GRB 170711A: Swift/UVOT Upper Limits DATE: 17/07/12 16:20:43 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170711A 124 s after the BAT trigger (D'Elia et al., GCN Circ. 21321). No optical afterglow consistent with the enhanced XRT position (Beardmore et al. GCN Circ. 21323) 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 initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag u_FC 124 374 246 >19.8 v 430 1553 136 >18.9 b 379 1503 156 >19.4 w1 480 1454 97 >19.6 m2 604 1429 58 >18.6 w2 704 1380 78 >19.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.31 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21331 SUBJECT: GRB 170711A: Swift-BAT refined analysis DATE: 17/07/12 19:23:15 GMT FROM: Hans Krimm at NSF/NASA-GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), V. D'Elia (ASDC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170711A (trigger #761622) (D'Elia, et al., GCN Circ. 21321). The BAT ground-calculated position is RA, Dec = 45.782, 47.845 deg which is RA(J2000) = 03h 03m 07.7s Dec(J2000) = +47d 50' 41.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single FRED-shaped peak, starting at T-2 sec, peaking at T+0 sec and decaying to background by T+6 sec. This is preceded by some weak, soft emission beginning at about T-25 sec. T90 (15-350 keV) is 31.3 +- 7.6 sec (estimated error including systematics). The time-averaged spectrum from T-31.66 to T+15.37 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.75 +- 0.10. The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.02 sec in the 15-150 keV band is 4.8 +- 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/761622/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21333 SUBJECT: GRB 170711A: ISON/Terskol and AbAO optical observations DATE: 17/07/13 18:13:15 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Pozanenko (IKI), A. Mokhnatkin (KIAM), R. Inasaridze (AbAO), E. Mazaeva (IKI), V. Agletdinov (KIAM), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 170711A (D'Elia et al. GCN 21321) with K-800 (0.8m) telescope of ISON/Terskol observatory starting on July, 12 (UT) 00:00:39 and AS-32 telescope of AbAO starting on July, 11 (UT) 23:58:46, i.e. about 1.6 hours after GRB trigger. We obtained several unfiltered images. We do not detect any source in stacked images within the enhanced XRT position (Beardmore et al. GCN 21323). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err. UL Telescope (mid, days) (s) 2017-07-11 23:58:46 0.07894 CR 11*60 n/d n/d 17.0 AS-32 2017-07-12 00:00:39 0.07658 CR 45*25 n/d n/d 19.1 K-800 Photometry is based on nearby stars of USNO-B1.0 USNO-B1.0_id R2 1378-0084355 14.59 1378-0084262 15.13 1378-0084218 14.70 We detect the object in coordinates (J2000) 03 03 11.46 +47 50 56.1 (+/- 0.5 arcsec) which is 7.7 arcsec apart from a center of the enhanced XRT position. The object is clearly detected in the stacked image of K-800 and marginally seen at the same position with AS-32 stacked image. The brightness of the object is 18.56 +/- 0.25 based on the reference stars listed above. The object is absent in the USNO-B1.0. At present, it is not clear whether this object has any relation to the GRB 170711A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21463 SUBJECT: GRB 170711A: 15 GHz upper limits from AMI DATE: 17/08/11 17:55:08 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 170711A (D'Elia et al., GCN 21321) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2017 Jul 12.14, Jul 13.38, Jul 16.29 and Jul 20.36 (UT) do not reveal any radio source at the XRT location (Beardmore et al., GCN 21323), with 3sigma upper limits of 186 uJy, 96 uJy, 102 uJy and 183 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.