Gamma-ray Burst 161010A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Mon 10 Oct 16 13:36:54 UT
  NOTICE_TYPE:    INTEGRAL Refined
  TRIGGER_NUM:    7599,   Sub_Num: 1
  GRB_RA:         275.2373d {+18h 20m 57s} (J2000),
                  275.5033d {+18h 22m 01s} (current),
                  274.4444d {+18h 17m 47s} (1950)
  GRB_DEC:        -28.7675d {-28d 46' 02"} (J2000),
                  -28.7588d {-28d 45' 31"} (current),
                  -28.7910d {-28d 47' 27"} (1950)
  GRB_ERROR:      2.68 [arcmin, radius, statistical only]
  GRB_INTEN:      17.32 [sigma]
  GRB_TIME:       49009.42 SOD {13:36:49.42} UT
  GRB_DATE:       17671 TJD;   284 DOY;   16/10/10
  SC_RA:          262.17 [deg] (J2000)
  SC_DEC:         -27.99 [deg] (J2000)
  SUN_POSTN:      196.30d {+13h 05m 13s}   -6.94d {-06d 56' 16"}
  SUN_DIST:        77.22 [deg]   Sun_angle= -5.3 [hr] (East of Sun)
  MOON_POSTN:     305.28d {+20h 21m 07s}  -16.22d {-16d 13' 28"}
  MOON_DIST:       30.11 [deg]
  GAL_COORDS:       3.95, -6.66 [deg] galactic lon,lat of the burst
  ECL_COORDS:     274.61, -5.41 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates.  
  COMMENTS:       Time_Scale=20.0000 and Time_Error=20.0000.  
  COMMENTS:       Possibly real GRB event  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Mon 10 Oct 16 13:39:38 UT
  NOTICE_TYPE:    INTEGRAL Refined
  TRIGGER_NUM:    7599,   Sub_Num: 2
  GRB_RA:         275.2399d {+18h 20m 58s} (J2000),
                  275.5059d {+18h 22m 01s} (current),
                  274.4471d {+18h 17m 47s} (1950)
  GRB_DEC:        -28.7647d {-28d 45' 52"} (J2000),
                  -28.7560d {-28d 45' 21"} (current),
                  -28.7883d {-28d 47' 17"} (1950)
  GRB_ERROR:      2.72 [arcmin, radius, statistical only]
  GRB_INTEN:      16.28 [sigma]
  GRB_TIME:       49005.42 SOD {13:36:45.42} UT
  GRB_DATE:       17671 TJD;   284 DOY;   16/10/10
  SC_RA:          262.17 [deg] (J2000)
  SC_DEC:         -27.99 [deg] (J2000)
  SUN_POSTN:      196.31d {+13h 05m 13s}   -6.94d {-06d 56' 18"}
  SUN_DIST:        77.22 [deg]   Sun_angle= -5.3 [hr] (East of Sun)
  MOON_POSTN:     305.30d {+20h 21m 13s}  -16.22d {-16d 13' 14"}
  MOON_DIST:       30.13 [deg]
  GAL_COORDS:       3.95, -6.66 [deg] galactic lon,lat of the burst
  ECL_COORDS:     274.61, -5.41 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates.  
  COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
  COMMENTS:       Possibly real GRB event  
  COMMENTS:          
  COMMENTS:       NOTE: This INTEGRAL event is temporally(14.0<100sec) coincident with the CALET_GBM event (trignum=1160141725).  
  

• GCN NOTICE
  

  TITLE:           GCN/CALET NOTICE
  NOTICE_DATE:     Mon 10 Oct 16 13:38:20 UT
  NOTICE_TYPE:     CALET GBM Flight Lightcurve
  POINT_RA:         33.12d {+02h 12m 28s} (J2000),
  POINT_DEC:       -13.37d {-13d 22' 04"} (J2000),
  TRIGGER_NUM:     1160141725
  TRIGGER_DATE:    17671 TJD;   284 DOY;   16/10/10
  TRIGGER_TIME:    48991.69 SOD {13:36:31.69} UT 
  TRIGGER_DET:     0 0 0 (HXM1 HXM2 SGM)
  SIGNIFICANCE:    6.40 [sigma]
  FOREGND_DUR:     4.00 [sec]
  BACKGND_DUR1:    16.00 [sec]
  ENERGY_BAND:     40-230 [keV]
  SC_LON_LAT:      169.57,-13.28 [deg]
  LC_URL:          http://cgbm.calet.jp/cgbm_trigger/flight//1160141725/index.html
  COMMENTS:        CALET-GBM Flight Lightcurve.
  COMMENTS:
  COMMENTS:        NOTE: This CALET_GBM_FLT_LC event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=7599).
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.
  

• GCN NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Mon 10 Oct 16 14:22:15 UT
  NOTICE_TYPE:    INTEGRAL Offline
  TRIGGER_NUM:    7599,   Sub_Num: 3
  GRB_RA:         275.2178d {+18h 20m 52s} (J2000),
                  275.4838d {+18h 21m 56s} (current),
                  274.4248d {+18h 17m 42s} (1950)
  GRB_DEC:        -28.7867d {-28d 47' 11"} (J2000),
                  -28.7780d {-28d 46' 40"} (current),
                  -28.8101d {-28d 48' 35"} (1950)
  GRB_ERROR:      1.50 [arcmin, radius, statistical only]
  GRB_INTEN:      16.28 [sigma]
  GRB_TIME:       49005.42 SOD {13:36:45.42} UT
  GRB_DATE:       17671 TJD;   284 DOY;   16/10/10
  SC_RA:          262.17 [deg] (J2000)
  SC_DEC:         -27.99 [deg] (J2000)
  SUN_POSTN:      196.33d {+13h 05m 20s}   -6.95d {-06d 56' 58"}
  SUN_DIST:        77.17 [deg]   Sun_angle= -5.3 [hr] (East of Sun)
  MOON_POSTN:     305.70d {+20h 22m 48s}  -16.16d {-16d 09' 34"}
  MOON_DIST:       30.52 [deg]
  GAL_COORDS:       3.92, -6.65 [deg] galactic lon,lat of the burst
  ECL_COORDS:     274.59, -5.43 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates.  
  COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
  COMMENTS:       refined_coordinates_after_offline_analysis  
  COMMENTS:          
  COMMENTS:       NOTE: This INTEGRAL event is temporally(14.0<100sec) coincident with the CALET_GBM event (trignum=1160141725).  
  

• GCN Circular #20021
  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
• GCN Circular #20022
  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.
• GCN NOTICE
  

  TITLE:          GCN/GRB_COUNTERPART POSITION NOTICE
  NOTICE_DATE:    Mon 10 Oct 16 21:34:30 UT
  NOTICE_TYPE:    Other
  TRIGGER_NUM:    20702 
  CNTRPART_RA:    275.2137d {+18h 20m 51.2s} (J2000),
                  275.4797d {+18h 21m 55.1s} (current), 
                  274.4207d {+18h 17m 40.9s} (1950)
  CNTRPART_DEC:   -28.7860d {-28d 47' 09.6"} (J2000),
                  -28.7773d {-28d 46' 38.2"} (current),
                  -28.8094d {-28d 48' 33.7"} (1950)
  CNTRPART_ERROR: 3.6 [arcsec, radius]
  GRB_DATE:       17671 TJD;   284 DOY;   16/10/10 
  GRB_TIME:       61021.00 SOD {16:57:01.00} UT
  OBS_DATE:       17671 TJD;   284 DOY;   16/10/10
  OBS_TIME:       61021.0 SOD {16:57:01.00} UT
  OBS_DUR:        977.8 [sec]
  INTENSITY:      1.10e-11 +/- 0.00e+00 [erg/cm2/sec]
  ENERGY:         0.3-10 [keV]
  TELESCOPE:      Swift-XRT
  SUBMITTER:      Phil_Evans
  SUN_POSTN:      196.61d {+13h 06m 26s}   -7.06d {-07d 03' 46"}
  SUN_DIST:        76.87 [deg]   Sun_angle= -5.3 [hr] (East of Sun)
  MOON_POSTN:     309.70d {+20h 38m 47s}  -15.50d {-15d 29' 49"}
  MOON_DIST:       34.20 [deg]
  MOON_ILLUM:     67 [%]
  GAL_COORDS:       3.92, -6.65 [deg] galactic lon,lat of the counterpart 
  ECL_COORDS:     274.59, -5.43 [deg] ecliptic lon,lat of the counterpart
  COMMENTS:       GRB COUNTERPART Coordinates.
  COMMENTS:       We cannot confirm whether this is the GRB or serendipitous.
  

• GCN Circular #20025
  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.
• GCN Circular #20027
  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.
• GCN Circular #20033
  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.
• GCN Circular #20034
  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).