GRB 190611B
GCN Circular 24845
Subject
GRB 190611B: AstroSat CZTI detection
Date
2019-06-18T04:27:34Z (6 years ago)
From
Prachee Ghumatkar at IUCAA/AstroSat <prachee@iucaa.in>
P. Ghumatkar, V. Sharma, D. Bhattacharya, T. Khanam and A. Vibhute (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 long GRB 190611B, which was also detected by Fermi GBM (Malacaria C. et al., GCN #24794), Global MASTER-Net (Lipunov V. et al., GCN #24795), IPN Triangulation (Hurley K. et al., GCN #24811), BALROG (Kunzweiler F. et al., GCN #24813), Konus-Wind (Frederiks D. et al., GCN #24827) and CALET (Cannady N. et al., GCN #24830).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with the strongest peak at 22:47:51.5 UT. Fermi/GBM lightcurve consists of two broad pulses. AstroSat could detect only first pulse of the burst, as during the second pulse the detector was in South Atlantic Anomaly (SAA). The measured peak count rate associated with the burst is 387 cts/s above the background in the combined data of four quadrants, with a total of 1251 cts. The local mean background count rate was 578 cts/s. Using cumulative rates, we measure a T90 of 7.35 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 24830
Subject
GRB 190611B: CALET Gamma-Ray Burst Monitor detection
Date
2019-06-14T14:25:24Z (6 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
N. Cannady (GSFC/UMBC),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The long, bright GRB 190611B (Fermi GBM detection: Malacaria and Meegan,
GCN Circ. 24794; IPN Triangulation: Hurley et al., GCN Circ. 24811; BALROG
localization: Kunzweiler et al., GCN Circ. 24813) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 22:47:46.257 UTC on 11 June 2019.
The burst signal was seen by all CGBM detectors.
The burst light curve shows two multi-peaked pulses: the first starts
at T+2.8 sec, peaks at T+4.9 sec and ends at T+16.9 sec, the second starts
at T+67.4 sec, peaks at T+75.4 sec and ends at T+118.8 sec. The T90 and
T50 durations measured by the SGM data are 100.9 +- 3.9 sec and
13.9 +- 1.1 sec (40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1244328454/
The CALET data used in this analysis are provided by the Waseda CALET
Operation Center located at the Waseda University.
GCN Circular 24827
Subject
Konus-Wind observation of GRB 190611B
Date
2019-06-14T12:22:39Z (6 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova,
A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 190611B
(Fermi GBM detection: Malacaria & Meegan, GCN 24794;
IPN triangulation: Hurley et al., GCN 24811)
triggered Konus-Wind (KW) at T0=82065.599 s UT (22:47:45.599).
The light curve of the burst shows two broad, multi-peaked pulses.
The total duration of the burst is ~130 s.
The emission is seen up to ~10 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190611_T82065/
As observed by Konus-Wind, the burst had
a fluence of (9.2 �� 1.0)x10^-5 erg/cm2 and
a 64-ms peak energy flux, measured from T0+17.344,
of (1.33 �� 0.11)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV
energy range).
The time-integrated spectrum (measured from T0 to T0+117.760 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.01 (-0.08,+0.08),
the high energy photon index beta = -2.74 (-0.88,+0.29),
the peak energy Ep = 250 (-21,+24) keV,
chi2 = 68/97 dof.
The spectrum near the peak count rate (measured from T0+67.840 s
to T0+77.568 s) is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.78 (-0.08,+0.09),
the high energy photon index beta = -2.20 (-0.13,+0.10),
the peak energy Ep = 307 (-29,+33) keV,
chi2 = 83/97 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
GCN Circular 24813
Subject
GRB 190611B: BALROG localization (Fermi Trigger 581986074 / GRB 190611950)
Date
2019-06-13T14:34:27Z (6 years ago)
From
Jochen Greiner at MPE,Garching <jcg@mpe.mpg.de>
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
581986074 at 22:47:49 on 11 June 2019 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 85.2+/-1.1 deg
Decl.(2000.0) = 52.0+/-1.0 deg
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB190611950/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB190611950/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB190611950/json
GCN Circular 24811
Subject
IPN Triangulation of GRB 190611B
Date
2019-06-13T14:03:15Z (6 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
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,
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team,
S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team,
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 190611B (Malacaria and Meegan, GCN Circ. 24794)
was detected by Fermi (GBM), Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), and Swift (BAT) at about 82069 s UT (22:47:49).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
84.968 (05h 39m 52s) +52.773 (+52d 46' 24")
Corners:
81.481 (05h 25m 55s) +50.833 (+50d 49' 57")
88.130 (05h 52m 31s) +54.352 (+54d 21' 06")
89.119 (05h 56m 29s) +54.477 (+54d 28' 38")
82.284 (05h 29m 08s) +51.059 (+51d 03' 34")
---------------------------------------------
The error box area is about 1.15 sq. deg, and its maximum
dimension is 5.9 deg (the minimum one is 6.42 arcmin).
The Sun distance was about 30 deg.
This box may be improved.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB190611_T82065/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 24794
Subject
GRB 190611B: Fermi GBM detection
Date
2019-06-12T18:39:54Z (6 years ago)
From
Christian Malacaria at NASA-MSFC/USRA <cmalacaria@usra.edu>
C. Malacaria (NASA-MSFC/USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 22:47:49.34 UT on the 11th of June 2019,
the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 190611B (trigger 581986074 / 190611950).
The on-ground calculated location, using the GBM trigger
data, is RA = 88.9, DEC = 53.1 (J2000 degrees,
equivalent to 05 h 56 m, 53 d 07 '), with a statistical uncertainty
of 1.0 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 angle from the Fermi LAT boresight
at the GBM trigger time is 117.0 degrees.
The GBM light curve consists of two broad pulses
with a duration (T90) of about 100.6 s (50-300 keV).
The time-averaged spectrum from T0-0.0 s to T0+18.2 s is
best fit by a Band function with Epeak = 210.3 +/- 18.9 keV,
alpha = -1.00 +/- 0.04, and beta = -1.98 +/- 0.05
The event fluence (10-1000 keV) in this time interval is
(2.43 +/- 0.40)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+71.8 s in the 10-1000 keV band
is 32.4 +/- 0.6 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info,
please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
[GCN OPS NOTE(16jun19), Per author's request, the "190611A"
in the first sentence was corrected to "190611B".]