//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18436 SUBJECT: GRB 151022A: Swift detection of a burst DATE: 15/10/22 14:22:47 GMT FROM: David Burrows at PSU/Swift P. D'Avanzo (INAF-OAB), D. N. Burrows (PSU), H. A. Krimm (CRESST/GSFC/USRA), A. Melandri (INAF-OAB), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 14:06:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151022A (trigger=661036). Swift slewed to the burst at T0+300 seconds. The BAT on-board calculated location is RA, Dec 349.213, +55.813 which is RA(J2000) = 23h 16m 51s Dec(J2000) = +55d 48' 48" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 20 sec. The peak count rate was ~1400 counts/sec (15-350 keV), at ~6 sec after the trigger. The XRT began observing the field at 14:11:32.6 UT, 300.5 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 349.19815, 55.81207 which is equivalent to: RA(J2000) = 23h 16m 47.56s Dec(J2000) = +55d 48' 43.5" with an uncertainty of 3.6 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 4.74 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 304 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. Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.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: 18437 SUBJECT: GRB 151022A: MASTER-Ural observations DATE: 15/10/22 14:32:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov, D. Vlasenko, E.Popova Lomonosov Moscow State University, Sternberg Astronomical Institute D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Ural was pointed to the GRB151022A 16 after notice time and 76 sec after trigger time at 2015-10-22 14:07:48 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (ra=23 16 51 dec=+55 48 47 r=0.05). The 5-sigma upper limit has been about 16.0 mag The reduction is continued. The message may be cited. [GCN OPS NOTE(23oct15): The GRB name in the Subject line was changed from "0922A" to "1022A".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18438 SUBJECT: GRB 151022A: Prompt enhanced Swift-XRT position DATE: 15/10/22 15:04:40 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 151022A, we find an enhanced XRT position of the afterglow: RA, Dec: 349.1969, 55.8119 which is equivalent to: RA (J2000) = 23 16 47.25 Dec (J2000) = +55 48 42.9 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/661036. 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: 18439 SUBJECT: GRB 151022A: Kanata/HOWPol optical observation DATE: 15/10/22 15:10:33 GMT FROM: Koji Kawabata at HASC,Hiroshima U K. S. Kawabata, R. Itoh, T. Nakaoka, M. Yoshida (Hiroshima Univ.), K. Tsumura (Tohoku Univ.), and K. Arimatsu (NAOJ) report on behalf of Kanata team: We performed a series of optical imaging-polarimetry for the optical afterglow of GRB151022A (D'Avanzo et al., GCN 18436) from 119 sec after the Swift/BAT trigger with HOWPol attached to the 1.5-m Kanata telescope at Higashi-Hiroshima Observatory, Japan. We could not detect any afterglow within the XRT error circle reported in the GCN 18436. We obtained the following preliminary upper limits (3-sigma) in our first image (mid-time 134 sec after the trigger) calibrated with UCAC4: Rc > 17.0 Further analysis is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18440 SUBJECT: GRB 151022A: MITSuME Okayama Ks-band upper-limit DATE: 15/10/22 15:51:57 GMT FROM: Kenshi Yanagisawa at OAO/NAOJ K. Yanagisawa, D. Kuroda, Y. Shimizu, H. Izumiura(OAO/NAOJ), M. Yoshida (Hiroshima), K. Ohta(Kyoto) and N. Kawai(Tokyo Tech.) report on behalf of the MITSuME collaboration: We observed the field of GRB 151022A (D'Avanzo et al., GCN 18436) in Ks-band with a wide-field near infrared imager at Okayama Astrophysical Observatory (Japan). The imager has effective aperture of 0.91 m. Observations started from 14:13 UT on 22th October, 0.12h after the BAT trigger, to 14:56 UT. The total exposure of 17.0 min was successfully obtained. In our co-add image, we did not find any new point source within the enhanced XRT error circle (Evans et al., GCN 18438) down to limiting magnitude of Ks=14.8 (Vega, S/N=10). The photometric calibration was made against 2MASS field stars. T0+[sec] MID-UT T-EXP[sec] Ks --------------------------------------------------- +1,721 14:35 1,020.0 >14.8 --------------------------------------------------- T0+ : Elapsed time after the burt [sec] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18441 SUBJECT: GRB 151022A: Mondy optical upper limit DATE: 15/10/22 19:35:01 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Klunko (ISTP), E. Mazaeva (IKI), A. Volnova (IKI), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of Swift GRB 151022A (D'Avanzo et al., GCN 18436) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Oct. 22 (UT) 15:05:04. We obtained several images in R-filter of 30 s exposure. Within XRT error circle (Evans, GCN 18438) we do not detect any optical source in any single image. Upper limit (3 sigma) of a single image is R ~ 19.4m. Photometry is based on nearly USNO-B1.0 (R2) stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18444 SUBJECT: GRB 151022A: Enhanced Swift-XRT position DATE: 15/10/22 23:32:37 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 2395 s of XRT Photon Counting mode data and 2 UVOT images for GRB 151022A, 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 = 349.19671, +55.81182 which is equivalent to: RA (J2000): 23h 16m 47.21s Dec (J2000): +55d 48' 42.6" 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18447 SUBJECT: GRB 151022A: MITSuME Okayama upper limits DATE: 15/10/23 00:53:18 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of MITSuME and OISTER collaboration: We observed the field of GRB 151022A (D'Avanzo et al., GCNC 18436) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2015-10-22 14:08:12 UT (~100 sec after the burst). We did not find any new point source within the enhanced XRT circle (Beardmore et al., GCNC 18444) in all the three bands. Three sigma upper limits of the OT are listed below. We used SDSS-DR8 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.00471 14:13:19 540.0 >19.0 >19.0 >18.3 0.04291 15:08:20 6240.0 >20.1 >19.9 >19.1 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18448 SUBJECT: GRB 151022A: Swift-XRT refined Analysis DATE: 15/10/23 02:22:04 GMT FROM: Phil Evans at U of Leicester S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU) and P. D'Avanzo report on behalf of the Swift-XRT team: We have analysed 6.4 ks of XRT data for GRB 151022A (D'Avanzo et al. GCN Circ. 18436), from 286 s to 31.4 ks after the BAT trigger. The data comprise 17 s in Windowed Timing (WT) mode (the first 7 s were 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. 18438). The light curve can be modelled with a power-law decay with a decay index of alpha=1.82 (+0.17, -0.14). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.39 (+0.26, -0.24). The best-fitting absorption column is 6.2 (+2.6, -1.5) x 10^21 cm^-2, consistent with the Galactic value of 4.7 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 6.1 x 10^-11 (7.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.2 (+2.6, -1.5) x 10^21 cm^-2 Galactic foreground: 4.7 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.39 (+0.26, -0.24) If the light curve continues to decay with a power-law decay index of 1.82, the count rate at T+24 hours will be 7.2 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.4 x 10^-15 (5.5 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00661036. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18449 SUBJECT: GRB 151022A: RATIR Upper Limits DATE: 15/10/23 05:37:43 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (GSFC/STScI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 151022A (D'Avanzo, et al., GCN 18436) 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 2015/10 23.16 to 2015/10 23.18 UTC (13.77 to 14.17 hours after the BAT trigger), obtaining a total of 0.36 hours exposure in the r, i, and z bands. For a source within the Swift-XRT error circle (Beardmore, et al., GCN 18444), in comparison with the SDSS DR9, we obtain the following upper limits (3-sigma): r > 23.11 i > 23.04 z > 19.84 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: 18452 SUBJECT: GRB 151022A: Swift-BAT refined analysis DATE: 15/10/23 17:34:15 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC),S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), P. D'Avanzo (INAF-OAB), N. Gehrels (GSFC),H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151022A (trigger #661036) (D'Avanzo, et al., GCN Circ. 18436). The BAT ground-calculated position is RA, Dec = 349.223, 55.812 deg which is RA(J2000) = 23h 16m 53.5s Dec(J2000) = +55d 48' 43.4" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 35%. The mask-weighted light curve shows a single FRED-like peak, with some superimposed structure, peaking near the trigger time and fading to near background by ~200 seconds. T90 (15-350 keV) is 116.7 +/- 23.0 sec (estimated error including systematics). The time-averaged spectrum from T-1.5 to T+132.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.98 +- 0.29. The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+10.37 sec in the 15-150 keV band is 0.8 +- 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/661036/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18456 SUBJECT: GRB 151022A: Swift/UVOT Upper Limits DATE: 15/10/23 20:11:49 GMT FROM: Mike Siegel at PSU/Swift MOC B. G. Balzer (PSU) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 151022A 304 s after the BAT trigger (D'Avanzo et al., GCN Circ. 18436). No optical afterglow consistent with the XRT position (Evans GCN Circ. 18438) 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 304 454 147 >21.2 white 304 7836 902 >22.0 v 461 8247 646 >20.1 b 560 7632 430 >21.0 u 535 7426 430 >21.2 w1 510 12075 553 >19.7 m2 486 8452 646 >20.3 w2 609 8042 627 >20.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.56 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18465 SUBJECT: GRB 151022A: OSN optical upper limit DATE: 15/10/24 11:29:51 GMT FROM: Samantha Oates at MSSL S. R. Oates (IAA-CSIC), S. Jeong (IAA-CSIC/SKKU), V. Casanova, J. C. Tello (IAA-CSIC) and A. J. Castro-Tirado (IAA-CSIC/UMA), report on behalf of a larger collaboration: We observed the field of GRB 151022A (D'Avanzo et al., GCN Circ. 18436) with the 1.5m OSN telescope at Observatorio de Sierra Nevada (Spain). The observations were carried out in the I band on Oct 22.79163 - 22.84025 (4.89 - 6.06 hours post bust). We do not detect any new optical source within the enhanced XRT error circle (Beardmore et al., GCN Circ. 18444) down to a limiting magnitude of I ~21.5 mag.