GRB 200125B
GCN Circular 26879
Subject
GRB 200125B: Fermi GBM Final Real-time Localization
Date
2020-01-25T20:53:50Z (5 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 20:43:31 UT on 25 Jan 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200125B (trigger 601677816.188054 / 200125864).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 7.5, Dec = 64.7 (J2000 degrees, equivalent to J2000 00h 30m, 64d 42'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 65.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200125864/quicklook/glg_skymap_all_bn200125864.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200125864/quicklook/glg_healpix_all_bn200125864.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200125864/quicklook/glg_lc_medres34_bn200125864.gif
GCN Circular 26880
Subject
GRB 200125B: BALROG localization (Fermi Trigger 601677816 / GRB 200125864)
Date
2020-01-25T21:20:59Z (5 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
601677816 at 20:43:31 on 25 Jan. 2020 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) = 7.7+/-0.8 deg
Decl.(2000.0) = 64.4+/-0.4 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200125864/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200125864/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200125864/json
GCN Circular 26888
Subject
GRB 200125B: Insight-HXMT/HE detection
Date
2020-01-26T14:10:22Z (5 years ago)
From
Ce Cai at IHEP <caice@ihep.ac.cn>
C. Cai, S. Xiao, Y. F. Du, Y. G. Zheng, Q. Luo, 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 2020-01-25T20:43:31.90 (T0), Insight-HXMT/HE detected
GRB 200125B (trigger ID: HEB200125863) in a routine search of the data,
which also triggered Fermi/GBM (GCN #26879).
The Insight-HXMT/HE light curve mainly consists of multiple
pulses with a duration (T90) of 4.66 s measured from T0-0.11 s.
The 1-ms peak rate, measured from T0+0.57 s, is 9038 cnts/sec.
The total counts from this burst is 18553 counts.
URL_LC: http://www.hxmt.org/images/GRB/HEB200125863_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 26893
Subject
GRB 200125B: Fermi GBM observations
Date
2020-01-27T02:06:37Z (5 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres, S. Poolakkil and C. Meegan (all UAH)
report on behalf of the Fermi GBM Team:
"At 20:43:31.19 UT on 25 January 2020, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located GRB 200125B
(trigger 601677816 / 200125864) (Fermi GBM Team, GCN #26879),
which was also detected by Insight-HXMT/HE (Cai et al., GCN #26888).
The GBM light curve consists of multiple overlapping pulses
with a duration (T90) of about 5.8 s (50-300 keV).
The time-averaged spectrum from T0 s to T0+12 s is
best fit by a Band function with Epeak = 175 +/- 3 keV,
alpha = -0.74 +/- 0.01, and beta = -2.23 +/- 0.02.
The event fluence (10-1000 keV) in this time interval is
(5.48 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band
is 103.7 +/- 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 Circular 26911
Subject
GRB 200125B: DDOTI/OAN optical observations report
Date
2020-01-28T06:04:23Z (5 years ago)
From
Emma Margarita Pereyra Talamantes at IA-UNAM Ensenada <mpereyra@astro.unam.mx>
Margarita Pereyra (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM),
Eleonora Troja (GSFC/UMD), Diego Gonzalez (UNAM), Alexander Kutyrev
(GSFC/UMD), William H. Lee (UNAM), and Tanner Wolfram (ASU), Simone
Dichiara (GSFC/UMD) report:
We observed the field of GRB 200125B detected by Fermi Gamma-ray Burst
Monitor (Fermi GBM Team, GCN Circ. 26879, Veres et al., GCN Circ. 26893),
with the DDOTI/OAN wide-field imager at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir (http://ddoti.astroscu.unam.mx) from
2020-01-26 02:18 to 2020-01-26 06:53 UTC (5.58 to 10.16 hours after the
event).
We observed a region of 6.8 degrees in RA by 10.2 degrees in declination
centered on the GBM Final Position 00:29:47 +64:41:22 J2000. This region
contains about 70 square degrees. We obtained about 3.1 hrs total exposure
across the region.
We calibrated our images against the APASS catalog. Our 10-sigma limiting
magnitude is w = 20.04 for a 2.0 degrees radius error region centered at
the GBM Final Position. Comparing to the USNO-B1 and PAN-STARRS DR1
catalogs we do not detect any uncataloged source with significant fading or
rising to our 10-sigma limit.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
--
*Dr. Margarita Pereyra *
*FFTF, Schlumberger Foundation Alumnae*
----------------------------------------------------------------------------------------------------------------
*Catedr��tico Conacyt*
*Instituto de Astronom��a de la UNAM,*
*Km. 107 Carretera Tijua**na-Ensenada, *
*Ensenada Baja California, M��xico. C.P. 22860*
Oficina: 405
Skype: margarita-pereyra
GCN Circular 26918
Subject
IPN triangulation of GRB 200125B
Date
2020-01-28T16:20:12Z (5 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,
K. Hurley, on behalf of the IPN,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team, and
S. Xiao, C. K. Li, X. B. Li, Y. Huang, and S. L. Xiong
on behalf of the Insight-HXMT/HE GRB team, report:
The long-duration, very bright GRB 200125B
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 26879;
BALROG localization: Biltzinger et al., GCN Circ. 26880;
Insight-HXMT/HE detection: Cai et al., GCN Circ. 26888)
was detected by Fermi (GBM trigger 601677816), Konus-Wind,
and Insight (HXMT/HE) at about 74611 s UT (20:43:31).
We have triangulated this GRB to a Konus-GBM annulus centered at
RA(2000)=321.900 deg (21h 27m 36s) Dec(2000)=-14.917 deg (-14d 55' 02")
whose radius is 86.537 +/- 0.136 deg (3 sigma) and a wider
Konus-HXMT annulus.
These annuli may be improved.
The annulus is consistent with, but reduces
the area of, the final Fermi-GBM (GCN Circ. 26879) and
BALROG (GCN Circ. 26880) localizations.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200125_T74611/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 26951
Subject
Konus-Wind observation of GRB 200125B
Date
2020-01-31T16:11:49Z (5 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, very bright GRB 200125B
(Fermi-GBM observations: The Fermi GBM team, GCN Circ. 26879;
Veres et al., GCN Circ. 26893;
BALROG localization: Biltzinger et al., GCN Circ. 26880;
Insight-HXMT/HE detection: Cai et al., GCN Circ. 26888;
IPN triangulation: Svinkin et al., GCN Circ. 26918)
triggered Konus-Wind at T0=74611.206 s UT (20:43:31.206).
The burst light curve shows a multipeaked structure
which starts at ~T0-0.5 s and has a total duration of ~10 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/GRB200125_T74611/
As observed by Konus-Wind, the burst
had a fluence of 6.01(-0.36,+0.37)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.312 s,
of 3.92(-0.44,+0.46)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+12.288 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.91(-0.06,+0.07),
the high energy photon index beta = -2.48(-0.15,+0.12),
the peak energy Ep = 211(-15,+16) keV
(chi2 = 98/97 dof).
The spectrum near the maximum count rate
(measured from T0+1.280 to T0+1.536 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 = -0.43(-0.14,+0.16),
the high energy photon index beta = -2.64(-0.34,+0.21),
the peak energy Ep = 295(-36,+39) keV
(chi2 = 63/51 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.