Gamma-ray Burst 170115B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 15 Jan 17 17:49:38 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     506195359
GRB_RA:          180.850d {+12h 03m 24s} (J2000),
                 181.070d {+12h 04m 17s} (current),
                 180.207d {+12h 00m 50s} (1950)
GRB_DEC:         -46.783d {-46d 46' 59"} (J2000),
                 -46.878d {-46d 52' 40"} (current),
                 -46.505d {-46d 30' 17"} (1950)
GRB_ERROR:       5.07 [deg radius, statistical plus systematic]
GRB_INTEN:       874 [cnts/sec]
DATA_SIGNIF:     65.90 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17768 TJD;    15 DOY;   17/01/15
GRB_TIME:        64154.03 SOD {17:49:14.03} UT
GRB_PHI:          70.00 [deg]
GRB_THETA:        30.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.34
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       297.76d {+19h 51m 03s}  -20.99d {-20d 59' 10"}
SUN_DIST:         91.45 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      159.58d {+10h 38m 18s}   +8.99d {+08d 59' 41"}
MOON_DIST:        59.06 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      294.44, 15.29 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      203.61,-41.65 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170115743/quicklook/glg_lc_medres34_bn170115743.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 142.33,-10.98 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 15 Jan 17 17:49:52 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      59
TRIGGER_NUM:     506195359
GRB_RA:          185.400d {+12h 21m 36s} (J2000),
                 185.630d {+12h 22m 31s} (current),
                 184.728d {+12h 18m 55s} (1950)
GRB_DEC:         -52.020d {-52d 01' 11"} (J2000),
                 -52.114d {-52d 06' 51"} (current),
                 -51.743d {-51d 44' 33"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     90.20 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        17768 TJD;    15 DOY;   17/01/15
GRB_TIME:        64154.03 SOD {17:49:14.03} UT
GRB_PHI:          58.00 [deg]
GRB_THETA:        30.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       297.76d {+19h 51m 03s}  -20.99d {-20d 59' 10"}
SUN_DIST:         86.18 [deg]   Sun_angle= 7.5 [hr] (West of Sun)
MOON_POSTN:      159.58d {+10h 38m 19s}   +8.99d {+08d 59' 39"}
MOON_DIST:        65.07 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      298.27, 10.58 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      210.90,-44.44 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170115743/quicklook/glg_lc_medres34_bn170115743.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_506195359.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1168537525).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sun 15 Jan 17 17:50:26 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      2
TRIGGER_NUM:     506195359
GRB_RA:          186.030d {+12h 24m 07s} (J2000),
                 186.262d {+12h 25m 03s} (current),
                 185.353d {+12h 21m 25s} (1950)
GRB_DEC:         -52.940d {-52d 56' 23"} (J2000),
                 -53.034d {-53d 02' 03"} (current),
                 -52.663d {-52d 39' 46"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     91.90 [sigma]
DATA_INTERVAL:   3.072 [sec]
GRB_DATE:        17768 TJD;    15 DOY;   17/01/15
GRB_TIME:        64154.03 SOD {17:49:14.03} UT
GRB_PHI:          56.00 [deg]
GRB_THETA:        30.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       297.76d {+19h 51m 03s}  -20.99d {-20d 59' 10"}
SUN_DIST:         85.39 [deg]   Sun_angle= 7.4 [hr] (West of Sun)
MOON_POSTN:      159.58d {+10h 38m 20s}   +8.99d {+08d 59' 34"}
MOON_DIST:        66.06 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      298.76,  9.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      212.07,-44.99 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2017/bn170115743/quicklook/glg_lc_medres34_bn170115743.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_506195359.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=7665).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 16 Jan 17 00:16:20 UT
NOTICE_TYPE:     Fermi-LAT Offline Position
TRIGGER_NUM:     506195359 
GRB_RA:          189.120d {+12h 36m 29s} (J2000),
                 189.355d {+12h 37m 25s} (current),
                 188.434d {+12h 33m 44s} (1950)
GRB_DEC:         -46.850d {-46d 51' 00"} (J2000),
                 -46.944d {-46d 56' 36"} (current),
                 -46.575d {-46d 34' 28"} (1950)
GRB_ERROR:       15.60 [arcmin radius, 90% containment, statistical only]
GRB_DATE:        17768 TJD;    15 DOY;   17/01/15
GRB_TIME:        64154.02 SOD {17:49:14.02} UT
TRIGGER_ID:      0x20000000
MISC:            0x40000000
SUN_POSTN:       298.05d {+19h 52m 12s}  -20.94d {-20d 56' 07"}
SUN_DIST:         86.75 [deg]   Sun_angle= 7.2 [hr] (West of Sun)
MOON_POSTN:      163.01d {+10h 52m 03s}   +7.96d {+07d 57' 21"}  
MOON_DIST:        59.68 [deg] 
MOON_ILLUM:      85 [%]
GAL_COORDS:      300.27, 15.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      209.99,-38.77 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi LAT Offline position.
COMMENTS:        This Notice was ground-generated -- not flight-generated.
COMMENTS:        It is the result of human-in-the-loop processing.
COMMENTS:        This is a human generated position of a LAT ground detection of GRB 170115B.        
COMMENTS:        This source corresponds to GBM trigger.

GCN Circular #20463
R. Hamburg (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 17:49:14.03 UT on 15 January 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170115B (trigger 506195359 / 170115743).
The on-ground calculated location, using the GBM trigger data, is RA = 189.03, DEC = -51.55, with an uncertainty of 1.43 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).
The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the GBM ground location is 32 degrees.
The GBM light curve consists of multiple peaks with a duration (T90) of about 44 s (50-300 keV). The time-averaged spectrum from T0-0.6 s to T0+42.4 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.89 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 1656 +/- 81 keV. A Band function fits the spectrum equally well with Epeak= 1563 +/- 106 keV, alpha = -0.88 +/- 0.01 and beta = -2.47 +/- 0.36.
The event fluence (10-1000 keV) in this time interval is (5.98 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.77 s in the 10-1000 keV band is 15.1 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #20464
J.E. McEnery, J. Racusin (NASA/GSFC) and E. Bissaldi (Politecnico & INFN Bari) report on behalf of the Fermi-LAT team:
At 17:49:14.03 on January 15, 2017 Fermi-LAT detected high-energy emission from GRB 170115B, which was also detected by Fermi-GBM (GCNC 20463).
The best LAT on-ground location is found to be
RA, Dec = 189.12, -46.85 (J2000)
with an error radius of 0.26 deg (90 % containment, statistical error only).
This was ~40 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance.
A Swift ToO has been requested for this burst.
The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #20466
V. Sharma, V. Bhalerao and D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed clear detection of GRB170115B (Fermi detection: R. Hamburg et al., GCN Circ. 20463) in the 40-200 keV energy range. The light curve shows multiple peaks structure with main peak at 17:49:14.03 UT, coincident with Fermi trigger. The measured peak count rate is 618.7 counts/sec above the background in combined data of four quadrants, with a total of 4196.9 counts. The local mean background count rate was 372.3 counts/sec. Using cumulative rates, we measure a T90 of 15.3 secs.
It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular #20467
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 170115B. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00062
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: 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 Circular #20474
F. Verrecchia (ASDC and INAF/OAR), A. Ursi (INAF/IAPS), F. Lucarelli (ASDC and INAF/OAR), F. Longo (Univ. Trieste and INFN Trieste), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata) report:
AGILE detected the long GRB 170115B, reported by Fermi-GBM (Hamburg et al. GCN #20463) and Fermi-LAT (McEnery et al. GCN #20464), at favourable off-axis angles between 0 and 30 deg. The AGILE-GRID detected the burst at about 4-sigma above 30 MeV with an extended gamma-ray emission lasting about 60 sec.
The AGILE MiniCaLorimeter (MCAL), sensitive in the energy range from 400 keV to 100 MeV, detected this burst that triggered the on-board sub-millisecond timescale logic. The MCAL light curve shows multiple peaks, from T0 until the end of the acquisition at T0 + 10.5 s. Three main peaks are evident during the first 2.5 sec following T0. During this time interval, the total number of counts is ~5500 for a background rate of 580 counts/s.
This measurement was obtained with AGILE observing a large portion of the sky in spinning mode.
GCN Circular #20475
K. Hurley, on behalf of the IPN,
I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 170115B (Fermi GBM detection: Hamburg et al., GCN 20463) has been detected by Fermi(GBM), Konus-Wind, INTEGRAL (SPI-ACS), and Mars-Odyssey(HEND), so far, at about 64154 s UT (17:49:14).
We have triangulated it to a Konus-HEND annulus centered at RA(2000)=171.562 deg (11h 26m 15s) Dec(2000)=+4.317 deg (+4d 19' 01"), whose radius is 53.310 +/- 0.093 deg (3 sigma).
This annulus intersects the Fermi-LAT 90% CL error circle (McEnery et al., GCN Circ. 20464) to form an error box whose area is about 2 times smaller than that of the LAT error circle, and whose corners are:
```
-----------------------------------------------
   RA(2000), deg       Dec(2000), deg
-----------------------------------------------
    Corners:
    189.426           -46.696
    189.079           -46.592
    188.888           -46.644
    188.743           -46.884
-----------------------------------------------
```
The box area is about 260 sq. arcmin.
This box may be improved.
A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB170115_T64155/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
GCN Circular #20476
D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report:
The long GRB 170115B (Fermi-GBM detection: Hamburg & Meegan, GCN 20463; Fermi-LAT detection: McEnery et al., GCN 20464; AstroSat CZTI observation: Sharma et al., GCN 20466; POLAR observation: Xiao et al., GCN 20469; AGILE detection: Verrecchia et al., GCN 20474; IPN triangulation: Hurley et al., GCN 20475) triggered Konus-Wind at T0=3D64155.241 s UT (17:49:15.241).
The light curve shows a bright, hard, multi-peaked pulse followed by a weaker emission; the total duration of the burst is ~50 s. The emission is seen up to ~10 MeV.
As observed by Konus-Wind, the burst had a fluence of (1.26 =B1 0.12)x10^-4 erg/cm2 and a 64-ms peak energy flux, measured from T0+0.512, of (3.1 =B1 0.2)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+38.144 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.86 (-0.06,+0.06), the high energy photon index beta =3D -2.49 (-0.90,+0.31), the peak energy Ep =3D 1114 (-156,+180) keV, chi2 =3D 94/97 dof.
The spectrum near the peak count rate (measured from T0 to T0+6.912 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha =3D -0.61 (-0.08,+0.08), the high energy photon index beta =3D -2.59 (-1.30,+0.32), the peak energy Ep =3D 1278 (-175,+223) keV, chi2 =3D 94/97 dof.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170115_T64155/
All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.
GCN Circular #20477
P. D'Avanzo (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 170115B in a series of observations tiled on the sky. The total exposure time is 4.7 ks, distributed over 5 tiles; the maximum exposure at a single sky location was 3.3 ks. The data were collected between T0+54.5 ks and T0+66.3 ks, and are entirely in Photon Counting (PC) mode.
One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below:
Source 1:
```
  RA (J2000.0):  189.0597  =  12:36:14.34
  Dec (J2000.0): -46.8311  =  -46:49:52.1
  Error: 6.5 arcsec (radius, 90% conf.)
  Count-rate: 0.0117 +/- 0.0029 ct s^-1   
  Distance: 163 arcsec from Fermi/LAT position.
```
The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/xrt_products/TILED_GRB00062.
This circular is an official product of the Swift-XRT team.
GCN Circular #20483
Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), 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 170115B (Hamburg et al., GCN Circ. 20463; McEnery et al., GCN Circ. 20464; Sharma et al., GCN Circ. 20466; Xiao et al., GCN Circ. 20469; Verrecchia et al., GCN Circ. 20474; Frederiks et al., GCN Circ. 20476) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 17:49:12.63 on 15 January 2017. The burst signal was only seen by the SGM instrument.
The light curve of the SGM shows several overlapping pulses starting at T0, peaking at T+3 sec and ending at T+15 sec. The T90 duration measured by the SGM data is 12.0 +- 0.9 sec (40-1000 keV).
The light curve is available at
http://cgbm.calet.jp/cgbm_trigger/flight/1168537525/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.
GCN Circular #20525
Y. Evangelista, L. Pacciani, E. Del Monte and I. Donnarumma (INAF/IAPS), A. Trois (INAF/OAC) on behalf of the AGILE Team, report:
SuperAGILE localised the long-duration GRB 170115B (Hamburg et al., GCN 20463; McEnery et al., GCN 20464; Sharma et al., GCN 20466; Xiao et al., GCN 20469; Verrecchia et al., GCN 20474; Frederiks et al., GCN 20476, Shimizu et al., GCN 20483) on 15 January 2017, at 17:49:14 UT.
The event had a duration of about 50.0 s in the 18-60 keV energy range, with a multi-peaked structure. The burst position was reconstructed as:
```
RA(J2000):       189.011 deg (12h 36m 02.64s)
DEC(J2000):      -46.796 deg (-46d 47' 45.58")
```
with an uncertainty of 5' (radius). The uncertainty accounts for both the statistical and systematic errors.
The SuperAGILE error box is completely contained in the FERMI-LAT error box (McEnery et al., GCN 20464) and partially intersects the IPN annulus (Hurley et al., GCN 20475). The Swift-XRT afterglow candidate (D'Avanzo et al., GNC 20477) is also contained in the SuperAGILE error box.
Due to telemetry downlink restrictions, the SuperAGILE experiment has been kept on but with no telemetry download since late 2012. The full telemetry link for the AGILE mission has now been restored and the data of SuperAGILE are again routinely downloaded.
This message may be cited.

Back to JG's homepage

Jochen Greiner, last update: 25-Jan-2017 [Disclaimer]