//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20021 SUBJECT: GRB 161010A: a long GRB detected by INTEGRAL DATE: 16/10/10 14:33:02 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA,Saclay), C.Ferrigno, E.Bozzo, M.Tuerler (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma ray burst lasting about 30 s has been detected by IBAS in the IBIS/ISGRI data at 13:36:32 UT of 2016 October 10. The refined coordinates (J2000) are: R.A.= 275.2178 deg DEC.= -28.7868 deg with an uncertainty of 1.5 arcmin (90% c.l.). The burst had a peak flux larger than 6 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range larger than 4e-6 erg/cmq. Note that due to telemetry saturation we can give only lower limits on fluence and peak flux. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20022 SUBJECT: GRB 161010A: Swift ToO observations DATE: 16/10/10 16:52:16 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the INTEGRAL GRB 161010A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020702 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the INTEGRAL event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20025 SUBJECT: GRB 161010A: Swift-XRT afterglow detection DATE: 16/10/11 07:31:55 GMT FROM: Antonino D'Ai at IASF-PA L.M. McCauley (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the INTEGRAL-detected burst GRB 161010A (Mereghetti et al. GCN Circ. 20021), collecting 5.0 ks of Photon Counting (PC) mode data between T0+12.0 ks and T0+30.3 ks. An uncatalogued X-ray source is detected consistent with being within 148 arcsec of the INTEGRAL position and is above the RASS limit and fading with 3-sigma significance, and is therefore likely the GRB afterglow. Using 123 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 275.21435, -28.78515 which is equivalent to: RA (J2000): 18h 20m 51.44s Dec(J2000): -28d 47' 06.6" with an uncertainty of 2.9 arcsec (radius, 90% confidence). This position is 12 arcsec from the INTEGRAL position. The light curve can be modelled with a power-law decay with a decay index of alpha=1.36 (+0.22, -0.21). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.78 (+0.18, -0.17). The best-fitting absorption column is 3.1 (+0.9, -0.6) x 10^21 cm^-2, consistent with the Galactic value of 2.5 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 (5.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.1 (+0.9, -0.6) x 10^21 cm^-2 Galactic foreground: 2.5 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.78 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 1.36, the count rate at T+24 hours will be 0.023 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.9 x 10^-13 (1.3 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis of the likely afterglow are at http://www.swift.ac.uk/ToO_GRBs/00020702/index_18.php. The results of the full analysis of the XRT observations are available at http://www.swift.ac.uk/ToO_GRBs/00020702. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20027 SUBJECT: Konus-Wind observation of GRB 161010A DATE: 16/10/11 14:32:00 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 161010A (INTEGRAL IBIS/ISGRI detection: Mereghetti et al., GCN Circ. 20021) triggered Konus-Wind at T0=48993.832 s UT (13:36:33.832). The burst light curve shows a single multipeaked emission episode started at T0-4.7 s with a total duration of ~22 s. The emission is seen up to 3 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB161010_T48993/ Note: 'dips' in the count rate are due to the GRB source occultation by the s/c structure. As observed by Konus-Wind, the burst had a fluence of 3.36(-0.38,+0.40)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+1.008 s, of 1.07(-0.26,+0.26)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 4 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.10(-0.19,+0.23), the high energy photon index beta = -2.17(-0.21,+0.13), the peak energy Ep = 205(-39,+56) keV (chi2 = 62/68 dof) All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20033 SUBJECT: GRB 161010A: CALET Gamma-Ray Burst Monitor detection DATE: 16/10/13 00:11:55 GMT FROM: Takanori Sakamoto at AGU K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), S. Nakahira (JAXA), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 161010A (Mereghetti et al., GCN Circ. 20021; Svinkin et al., GCN Circ. 20027; McCauley et al., GCN Circ. 20025) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 13:36:31.69 on 10 October 2016. The burst signal was seen by the SGM instrument. The light curve of the SGM shows a single weak peak starting at T0, peaking at T+3 sec and ending at T+8 sec. The T90 duration measured by the SGM data is 4.9 +- 0.5 sec (40-1000 keV). The light curve is available at http://cgbm.calet.jp/cgbm_trigger/flight/1160141725/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20034 SUBJECT: GRB 161010A: Swift/UVOT Possible Detection DATE: 16/10/13 12:53:23 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 161010A 3.3 hours after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 20021). A source consistent with the XRT position (McCauley et al., GCN Circ. 20025) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 18:20:51.27 = 275.21364 (deg.) Dec (J2000) = -28:47:06.7 = -28.78519 (deg.) with an estimated uncertainty of about 1 arc sec. (radius, 90% confidence). As shown in the table below, the source faded in the observations using the U filter, suggesting that it could be the afterglow of the GRB. However, the GRB is only 7.8 degrees from the direction of the Galactic Center, and this is a crowded field for UVOT. Consequently, the association of the source with the GRB is not certain. Preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are: Filter T_start(s) T_stop(s) Exp(s) Mag u 12034 13628 1035 18.8 +/- 0.1 u 17802 19985 744 19.0 +/- 0.1 u 23563 25993 794 19.4 +/- 0.2 u 29338 30137 787 20.4 +/- 0.4 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.54 in the direction of the burst (Schlegel et al. 1998).