- GCN/BACODINE POSITION NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Fri 24 Nov 17 11:02:02 UT
NOTICE_TYPE: Fermi-LAT Offline Position
TRIGGER_NUM: 533194681
GRB_RA: 335.520d {+22h 22m 05s} (J2000),
335.720d {+22h 22m 53s} (current),
334.961d {+22h 19m 51s} (1950)
GRB_DEC: +35.220d {+35d 13' 12"} (J2000),
+35.311d {+35d 18' 38"} (current),
+34.967d {+34d 58' 02"} (1950)
GRB_ERROR: 12.00 [arcmin radius, 90% containment, statistical only]
GRB_DATE: 18081 TJD; 328 DOY; 17/11/24
GRB_TIME: 20276.50 SOD {05:37:56.50} UT
TRIGGER_ID: 0x20000000
MISC: 0x40000000
SUN_POSTN: 240.28d {+16h 01m 07s} -20.63d {-20d 37' 46"}
SUN_DIST: 106.02 [deg] Sun_angle= -6.4 [hr] (East of Sun)
MOON_POSTN: 309.55d {+20h 38m 11s} -17.58d {-17d 34' 33"}
MOON_DIST: 58.42 [deg]
MOON_ILLUM: 29 [%]
GAL_COORDS: 91.46,-18.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 353.77, 41.59 [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.
COMMENTS: This source corresponds to GBM trigger.
- GCN Circular #22155
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/LAT GRB 171124A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020784
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 Fermi/LAT 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 Circular #22156
F. Longo (University and INFN, Trieste), M. Arimoto (Waseda University),
E. Bissaldi (Politecnico and INFN Bari) and M. Palatiello (University
and INFN, Trieste)
report on behalf of the Fermi-LAT collaboration:
At 05:37:56.50 UT on November 24, 2017, Fermi-LAT
detected high-energy emission from GRB 171124A, which was also
detected by Fermi-GBM (trigger 533194681 / 171124235).
The best LAT on-ground location is found to be
RA, Dec = 335.52, 35.22 deg (J2000)
with an error radius of 0.18 deg (90 % containment, statistical error
only).
This was 19 deg from the LAT boresight at the time of the trigger.
More than 10 photons with Energy > 100 MeV are associated to
the GRB in 350 s. The highest-energy photon is a 3.5 GeV event,
which is observed 4 seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst
is Francesco Longo (francesco.longo@ts.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 #22159
K. Shiraishi, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K.
Morita, T.
Ozawa, H. Mamiya, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 171124A (F. Longo et
al., GCN Circular #22156) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.
The observation started on 2017-11-24 11:02:40.53 UT. We did not find any
new point source within enhanced LAT circle in all three bands.
We obtained following limits for the magnitudes.
T0+[hour] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------------------------------------------------
~6.38 12:00:00 300 >19.0 >18.5 >17.4
-------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used UCAC-4 catalog for flux calibration.
- GCN Circular #22165
J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), K.L. Page (U. Leicester), A.P. Beardmore
(U. Leicester) 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 171124A (Longo et al. GCN Circ. 22156),
collecting 4.6 ks of Photon Counting (PC) mode data between T0+21.8 ks
and T0+33.1 ks.
Four uncatalogued X-ray sources have been detected, however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the
afterglow. Details of these sources are given below:
Source 1:
RA (J2000.0): 335.42198 = 22:21:41.28
Dec (J2000.0): +35.14890 = +35:08:56.0
Error: 2.8 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: (7.5 +/- 1.5)e-3 ct s^-1
Distance: 385 arcsec from Fermi/LAT position.
Flux: (1.85 +/- 0.38)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 2:
RA (J2000.0): 335.47618 = 22:21:54.28
Dec (J2000.0): +35.33200 = +35:19:55.2
Error: 2.3 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.0243 +/- 0.0029 ct s^-1
Distance: 423 arcsec from Fermi/LAT position.
Flux: (7.33 +/- 0.86)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 3:
RA (J2000.0): 335.3767 = 22:21:30.42
Dec (J2000.0): +35.1638 = +35:09:49.7
Error: 4.6 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: (3.52 [+1.20, -0.99])e-3 ct s^-1
Distance: 467 arcsec from Fermi/LAT position.
Flux: (1.10 [+0.38, -0.31])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 4:
RA (J2000.0): 335.49592 = 22:21:59.02
Dec (J2000.0): +35.16340 = +35:09:48.2
Error: 2.8 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: (5.6 +/- 1.3)e-3 ct s^-1
Distance: 215 arcsec from Fermi/LAT position.
Flux: (2.04 +/- 0.49)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020784.
This circular is an official product of the Swift-XRT team.
- GCN Circular #22164
E. Bissaldi (Politecnico & INFN Bari) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:
"At 05:37:56.50 UT on 24 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171124A (trigger 533194681 / 171124235),
which was also detected by Fermi LAT (Longo et al. 2017, GCN 22156).
The GBM on-ground location is consistent with the LAT position.
The angle from the Fermi LAT boresight at the GBM trigger time is 19 degrees.
The GBM light curve consists of two emission episodes
with a duration (T90) of about 26 s (50-300 keV).
The time-averaged spectrum from T0-1.3 s to T0+22 s is
well fit by a Band function with Epeak = 1.12 +/- 0.28 MeV,
alpha = -1.01 +/- 0.05, and beta = -2.10 +/- 0.22.
The event fluence (10-1000 keV) in this time interval is
(1.1 +/- 0.3)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.3 s in the 10-1000 keV band
is 4.5 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
- GCN Circular #22168
V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of Astrosat CZTI data showed the detection of a GRB 171124A, which was also detected by Fermi-LAT (Longo F. et al., GCN 22156) and Fermi-GBM (Bissaldi E. et al., GCN 22164).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 05:38:00.500 UT, ~4 s after the Fermi trigger. The measured peak count rate is 161.3 cts/s above the background in combined data of four quadrants, with a total of 1157 cts. The local mean background count rate was 424.7 cts/s. Using cumulative rates, we measure a T90 of 8.4 s.
It was also clearly detected in the CsI anticoincidence (Veto) detector 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 #22171
X.F. Li, S. L. Xiong, X. B. Li, C. K. Li, C. Z. Liu,
Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
During the commissioning phase, at 2017-11-24T05:38:03.000 (T0),
Insight-HXMT/HE detected GRB 171124A (trigger ID: HEB171124234)
in a routine search of the data=EF=BC=8Cwhich was also observed by
Fermi-LAT (F. Longo et al, GCN Circ.22156), Fermi/GBM(E. Bissaldi=20
et al, GCN Circ.22164)=EF=BC=8CAstroSat CZTI=EF=BC=88V. Sharma et al=EF=BC=
=8CGCN Circ.22168=EF=BC=89.
The Insight-HXMT light curve mainly consists of two emission episodes
with a duration (T90) of 17.27 s measured from T0-5.66 s.
The 1-s peak rate, measured from T0-0.007 s, is 924.7 cnts/sec.
The total counts from this burst is 3968.2 counts.
URL_LC: http://www.hxmt.org/images/GRB/HEB171124234_lc.jpg
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
The analysis results presented above are preliminary;
final results will be published elsewhere.
Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .
- GCN Circular #22174
J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), K.L. Page (U. Leicester), A.P. Beardmore
(U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
Fermi/LAT-detected burst GRB 171124A (Longo et al. GCN Circ. 22156).
The observations now extend from T0+21.8 ks to T0+579.1 ks.
Of the sources reported by Osborne et al. (GCN Circ. 22165), "Source 2"
is fading with 3-sigma significance, and is therefore likely the GRB
afterglow. Using 4982 s of PC mode data and 3 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 335.47598, +35.33213
which is equivalent to:
RA (J2000): 22h 21m 54.24s
Dec(J2000): +35d 19' 55.7"
with an uncertainty of 2.3 arcsec (radius, 90% confidence). This
position is 7.1 arcmin from the Fermi/LAT position. The source is
fading with alpha >0.7.
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.8 (+0.8, -0.7). The
best-fitting absorption column is 7.9 (+4.7, -3.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 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 2.9 x 10^-11 (1.0 x 10^-10) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 7.9 (+4.7, -3.5) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 3.1 sigma
Photon index: 2.8 (+0.8, -0.7)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020784.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020784.
This circular is an official product of the Swift-XRT team.
- GCN Circular #22175
E. Mazaeva (IKI), A. Pozanenko (IKI), A. Kusakin (FAPHI), I. Reva
(FAPHI), A. Volnova (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the field of the Fermi/LAT-detected burst GRB 171124A
(Longo et al. GCN 22156) with Zeiss-1000 1-m telescope of Tien Shan
Astronomical Observatory starting on Nov. 27 (UT) 12:28:32. We took
several images in R-filter with exposures of 120 s. We cover all LAT-
localization region.
The three XRT sources ## 1,3,4 (Osborne et al. GCN 22165) are
detected in our stacked image. These sources are also presented in the
USNO-B1.0 catalogue. We do not detect any optical object within X-ray
afterglow (XRT #2 error circle, Osborne et al. GCN 22174). We may
note that 4.5 arcsec South of XRT #2 we detect a galaxy which is also
present in USNO-B1.0.
Preliminary photometry of the field is following:
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s) (3 sigma)
2017-11-27 12:28:32 3.31825 R 40*120 n/d n/d 22.0
The finding chart of the 32 XRT source can be found at
http://grb.rssi.ru/GRB171124A/GRB171124A_XRT2.png
The photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
1251-0500105 14.64
1252-0499091 16.06
1251-0500220 15.86
1251-0500271 16.17
1251-0500270 16.12
1251-0500372 16.06
- GCN Circular #22210
A. Tezuka, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada,
S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), 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),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The long-duration GRB 171124A (Longo et al., GCN circ. 22156; Bissaldi et al.,
GCN circ. 22164; Sharma et al., GCN circ. 22168; Li et al., GCN circ. 22171) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 05:37:55.34 on 24 November 2017.
The burst signal was only seen by the SGM instrument.
The light curve of the SGM shows several peaks. The emission starts
at T0, peaks at T+9 sec and ends at T+21 sec. The T90 duration measured
by the SGM data is 17.8 +- 0.5 sec (40-1000 keV).
The light curve is available at
http://cgbm.calet.jp/cgbm_trigger/flight/1195536953/
The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.
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