GRB 190220B
GCN Circular 23915
Subject
GRB 190220B: a long GRB detected by IBAS
Date
2019-02-20T22:01:11Z (6 years ago)
From
Diego Gotz at CEA <diego.gotz@cea.fr>
D.Gotz (CEA, Saclay), S.Mereghetti (INAF, IASF-Milano), C.Ferrigno,
E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC,
Versoix) and J.Borkowski (CAMK, Torun) report:
a gamma ray burst lasting about 200 s with a multi-peaked structure has been detected by IBAS in the
IBIS/ISGRI data at 20:12:43 UT of February 20, 2019.
The refined coordinates (J2000) are:
R.A.= 242.4512 deg
DEC.= -21.1314 deg
with an uncertainty of 2.0 arcmin (90% c.l.).
The burst had a peak flux of 0.2 counts/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 3.6e-6
erg/cmsq.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 23916
Subject
GRB 190220B: BOOTES-4 optical observation
Date
2019-02-20T23:05:52Z (6 years ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Y.-D. Hu, X.-Y.Li, E. Fernandez-Garcia, A. Ayala, A. J. Castro-Tirado
(IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de
Malaga),�� S. Guziy (Univ. of Nikolaev) and D. Xiong, Y. Fan, X. Zhao, J.
Bai, C. Wang, Y. Xin (Yunnan Nacional Astronomical Observatory) on
behalf of a larger collaboration, report:
"Following the detection of GRB 190220B by INTEGRAL (Gotz et al. GCNC
23915), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical
Observatory (China) responded to the the burst gathering images starting
at 20:17:12 UT (89 s after trigger, 84 s after notice). No optical
afterglow candidate is found down to 18 mag (g'-band) in the co-added
(5x10s) image within the reported INTEGRAL 2 arcmin radius error box.
Observations are ongoing."
GCN Circular 23919
Subject
GRB 190220B: Kitab Observatory optical upper limit
Date
2019-02-21T14:58:34Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Novichonok (KIAM), A. Pozanenko (IKI), E. Mazaeva
(IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger
GRB follow-up collaboration:
We observed the field of INTEGRAL GRB 190220B (Gotz et al., GCN 23915)
with RC-36 0.36-m telescope of Kitab Observatory starting on Feb. 20
(UT) 23:20:25 in Clear filter. We do not find any optical afterglow
candidate in the INTEGRAL GRB 190220B localization error circle (Gotz,
et al., GCN 23915) with is in agreement with earlier non detection by
BOOTES-4 (Hu et al., GCN 23916). Preliminary photometry of the field is
following.
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2019-02-20 23:20:25 0.14972 CR 48*60 19.0 n/d n/d
The photometry is based on the nearby USNO-B1 (R2) stars.
.
GCN Circular 23921
Subject
GRB 190220B: Fermi GBM observation
Date
2019-02-21T19:49:45Z (6 years ago)
From
Cori Fletcher at USRA/NASA <corinne.l.fletcher@nasa.gov>
C. Fletcher (USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 20:15:31.49 UT on 20 February 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190220B (trigger 572386536 / 190220844).
which was also detected by INTEGRAL (Gotz et al. 2019, GCN 23915).
The GBM on-ground location is consistent with the INTEGRAL position.
The angle from the Fermi LAT boresight at the GBM trigger time is 23 degrees.
The GBM light curve consists of multiple peaks
with a duration (T90) of about 109 s (50-300 keV).
The time-averaged spectrum from T0-51.201 s to T0+59.393 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.4 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 83 +/- 8 keV
The event fluence (10-1000 keV) in this time interval is
(7.2 +/- 0.6)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+38.72 s in the 10-1000 keV band
is 2.5 +/- 0.2 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 73 +/- 13 keV, alpha = -1.3 +/- 0.2 and beta = -2.5 +/- 0.4.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."