Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

GRB 190901A

GCN Circular 25687

Subject
GRB 190901A: AstroSat CZTI detection
Date
2019-09-09T11:17:45Z (6 years ago)
From
Ramkrishna Gaikwad at IUCAA/AstroSat <ramkrishna@iucaa.in>
R. Gaikwad, 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 190901A, which was also detected by Fermi GBM Final Real-time Localization (GCN #25601), BALROG localization (Biltzinger B. et al., GCN #25602), Global MASTER-Net (Lipunov V. et al., GCN #25603), Insight-HXMT/HE (Yao J. M. et al., GCN # 25646).

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 2019-09-01 21:21:49.0 UT. The measured peak count rate associated with the burst is 215 cts/s above the background in the combined data of four quadrants, with a total of 891 cts. The local mean background count rate was 572 cts/s. Using cumulative rates, we measure a T90 of 13.4 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 25646

Subject
GRB 190901A: Insight-HXMT/HE detection
Date
2019-09-04T06:48:31Z (6 years ago)
From
Ce Cai at IHEP <caice@ihep.ac.cn>
J. M. Yao, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, 
Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, 
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2019-09-01T21:21:57.80 (T0), Insight-HXMT/HE detected 
GRB 190901A (trigger ID: HEB190901890) in a routine search of the data, 
which was also triggered by Fermi GBM (GCN #25601).

The Insight-HXMT/HE light curve mainly consists of a single  
pulse with a duration (T90) of 15.69 s measured from T0-3.00 s. 
The 1-ms peak rate, measured from T0+0.95 s, is 1500 cnts/sec. 
The total counts from this burst is 12538 counts. 
URL_LC: http://www.hxmt.org/images/GRB/HEB190901890_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 (deposited 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. 

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.

GCN Circular 25602

Subject
GRB 190901A: BALROG localization (Fermi Trigger 589065714 / GRB 190901890)
Date
2019-09-01T21:51:54Z (6 years ago)
From
Jochen Greiner at MPE,Garching <jcg@mpe.mpg.de>
B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
589065714 at 21:21:49 on 01 Sept. 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) = 224.7+/-0.8 deg
Decl.(2000.0) = -0.5+/-1.1 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB190901890/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB190901890/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB190901890/json

GCN Circular 25601

Subject
GRB 190901A: Fermi GBM Final Real-time Localization
Date
2019-09-01T21:31:54Z (6 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB

At 21:21:49 UT on 1 Sep 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 190901A (trigger 589065714.612092 / 190901890).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 220.3, Dec = 0.9 (J2000 degrees, equivalent to J2000 14h 41m, 0d 54'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 85.0 degrees.

The skymap can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_skymap_all_bn190901890.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_healpix_all_bn190901890.fit

The GBM light curve can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190901890/quicklook/glg_lc_medres34_bn190901890.gif

Looking for U.S. government information and services? Visit USA.gov