GRB 190919B
GCN Circular 25788
Subject
GRB 190919B: A long GRB detected by INTEGRAL
Date
2019-09-20T00:41:44Z (6 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), 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 30 s has been detected by IBAS in the
IBIS/ISGRI data at 23:46:40 UT of September 19, 2019.
The refined coordinates (J2000) are:
R.A.= 311.8862 deg
DEC.= -44.7029 deg
with an uncertainty of 1.5 arcmin (90% c.l.).
The burst had a peak flux of 0.6 ph/cm2/s (20-200 keV, 1-s integration
time) and a fluence in the same energy range of about 3e-7 erg/cm2.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 25789
Subject
GRB 190919B: GROND detection of the NIR afterglow
Date
2019-09-20T02:30:15Z (6 years ago)
From
Jan Bolmer at MPE/Garching <jan@bolmer.de>
J. Bolmer (MPE Garching) report:
We observed the field of GRB 190919B (INTEGRAL trigger 8377; Mereghetti et al. GCN 25788)
simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted
at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 23:50 UT on 19 September 2019, 3.6 min after the GRB trigger.
They were performed at an average seeing of 1.31" and at an average airmass of 1.2. We
detect the fading NIR afterglow at the following coordinates and with the following
preliminary AB magnitudes at 407 +/- 194 s after the trigger:
Ra, Dec = 311.87765 -44.69533
J = 16.33 +/- 0.05,
H = 16.06 +/- 0.05,
Ks = 15.92 +/- 0.07.
Given magnitudes are calibrated against 2MASS field stars and are not corrected
for the expected Galactic foreground extinction corresponding to a reddening of
E_(B-V)=0.10 mag in the direction of the burst (Schlafly & Finkbeiner 2011).
GCN Circular 25790
Subject
GRB 190919B: Swift ToO observations
Date
2019-09-20T07:01:17Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the INTEGRAL GRB 190919B.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00020948
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 INTEGRAL 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 25791
Subject
GRB 190919B: MASTER OT early detection at GROND position
Date
2019-09-20T07:30:40Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
N.Tyurina, V. Lipunov, E. Gorbovskoy, V.Kornilov, F.Balakin,
P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov,
D.Zimnukhov,V.Senik, T.Pogrosheva, K.Pozdnyakov,
A.Chasovnikov, V.Topolev, D.Kuvshinov(Lomonosov Moscow State University, SAI,
Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix
Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova(Irkutsk State University, API),
A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State
University)
We see GRB190919B (INTEGRAL trigger 8377; Mereghetti et al. GCN 25788) at
prompt and afterglow stage with flare (after 7 min) on several MASTER
telescopes (Lipunov et al., GCN 25787) at GROND position (Bolmer et al, 25789).
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/event.php?id=1136619
The OT coordinates are:
RA, Dec = 20h 47m 30.56s , -44d 41m 42s.5
Error = 0.3 arcsec
The observation and reduction will be continued.
The message may be cited.
GCN Circular 25792
Subject
GRB 190919B: VLT/X-shooter redshift
Date
2019-09-20T08:30:58Z (6 years ago)
From
Daniele B Malesani at DTU Space <malesani@space.dtu.dk>
G. Pugliese (Univ. Amsterdam), L. Izzo (DARK/NBI), J. Bolmer (MPE
Garching), N. R. Tanvir (Univ Leicester), D. B. Malesani (DTU Space), D.
Xu (NAO/CAS), D. A. Kann (HETH/IAA-CSIC), J. P. U. Fynbo (DAWN/NBI),
report on behalf of the Stargate collabaration:
We observed the optical afterglow (Bolmer, GCN 25789) of the INTEGRAL
GRB 190919B (Mereghetti et al., GCN 25788) using the ESO VLT UT2
(Kueyen) equipped with the X-shooter spectrograph. Our spectra cover the
wavelength range 3000-24700 AA, and consist of 4 exposures by 600 s
each. The observation mid time was 2019 Sep 20.194 UT (4.87 hr after the
GRB).
In a 30 s image taken with the acquisition camera on Sep 20.1714 UT, we
detect the optical afterglow, for which we measure a magnitude r = 20.10
+- 0.02 AB (calibrated against nearby stars from the SkyMapper catalog;
Wolf et al. 2018, PASA, 35, 010; https:doi.org/10.4225/41/593620ad5b574).
We clearly detect continuum over the full covered wavelength range. A
wide trough is visible around 5130 AA, which we identify as due to H I.
This is confirmed by the presence of the Ly alpha forest blueward of
this wavelength. We also detect multiple, narrow absorption features
across all the three arms, which we interpret as due to e.g. S II, Si
II, O I, S IV, C IV, Fe II, Mg II, Ca I, at a common redshift z = 3.225.
We acknowledge excellent support from the ESO observing staff in
Paranal, in particular Pedro Figueira, Nestor Jimenez, Camila Navarrete,
and Juan Carlos Olivares.
GCN Circular 25793
Subject
GRB 190919B: Swift-XRT observations
Date
2019-09-20T14:05:48Z (6 years ago)
From
Andy Beardmore at U Leicester <ab271@leicester.ac.uk>
A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B.
Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L.
Page (U. Leicester), P. D'Avanzo (INAF-OAB) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 190919B (Mereghetti et al. GCN Circ. 25788), collecting 3.0
ks of Photon Counting (PC) mode data between T0+28.6 ks and T0+36.4 ks.
An uncatalogued X-ray source has been detected 1.1 arcsec from the
reported GROND afterglow position (Bolmer, GCN Circ. 25789):
Source 1:
RA (J2000.0): 311.87783 = 20:47:30.68
Dec (J2000.0): -44.69542 = -44:41:43.5
Error: 2.1 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.0222 [+0.0032, -0.0031] ct s^-1
Distance: 0 arcsec from INTEGRAL position.
Flux: (7.16 [+1.03, -0.98])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
The source is below the RASS limit and, due to the limited amount of
data available so far, shows no signs of fading.
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00020948.
This circular is an official product of the Swift-XRT team.
GCN Circular 25794
Subject
GRB 190919B: FRAM-Auger optical detection
Date
2019-09-20T15:00:30Z (6 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Martin Jelinek (ASU CAS Ondrejov, CZ), Sergey Karpov,
Martin Masek, Petr Janecek, Jakub Jurysek, Jan Ebr, Ronan Cunniffe,
Petr Travnicek, Michael Prouza (Institute of Physics, Prague, CZ)
and Jan Strobl (ASU CAS Ondrejov, CZ)
report:
The 30 cm robotic telescope FRAM-Auger in Malargue (Argentina)
reacted robotically to the INTEGRAL/IBAS alert of GRB190919B
(Mereghetti et al., GCNC 25788), starting with a series of 20 s
unfiltered images at 23:47:16 UT, i.e. 36 s post trigger.
We clearly detect the optical afterglow reported by Bolmer (GCN
25789), Tyurina et al. (GCN 25791) and Pugliese et al. (GCN
25792) at single frames. The optical lightcurve seems to have
a multi-peak structure with maxima reaching r'(AB) ~ 16.5 mag,
and fades beyond the single-image detection limit of r' ~ 17.2 by
~ 10 minutes post trigger. A detailed analysis is ongoing.
GCN Circular 25795
Subject
GRB 190919B: Swift/UVOT Upper Limits
Date
2019-09-20T20:58:25Z (6 years ago)
From
Frank Marshall at Swift/UVOT <marshall@milkyway.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and A. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190919B
28564 s after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 25788).
No optical afterglow consistent with the optical position
(Bolmer, GCN Circ. 25789; Tyurina et al. GCN Circ. 25791)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u_FC 28987 29196 206 >20.3
v 30258 36440 225 >19.6
b 29201 36022 301 >20.2
u 28987 35920 301 >20.7
w1 28564 35819 602 >20.8
m2 30471 30737 262 >20.3
w2 29416 36416 1204 >21.8
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 25796
Subject
GRB 190919B: LCO Optical Afterglow Detection
Date
2019-09-21T02:24:34Z (6 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Fermi GRB 190919B (Mereghetti, GCN 25788) with
the LCO 1-m Sinistro instrument on September 20, from 17:58 to 19:10 UT
(corresponding to 18.27 to 19.47 hours from the GRB trigger time)
with the SDSS i� and r� filters.
We performed a series of 28x30s exposures in each band. We do not detect the source in individual frames; however we detect a source in stacked images (at least 5 stacked images) that is not present in USNO-B1.0 or 2MASS surveys with
the following magnitudes:
i = 20.60 +/- 0.14
r = 21.48 +/- 0.18
This flux measurement may be partially contaminated by the host galaxy, and it is calibrated against several USNO-B1.0 objects near the GRB location but is not corrected for Galactic Extinction.
Analysis is ongoing to determine if the source is fading over the course of the observations, and therefore likely the GRB afterglow.
These observations were possible thanks to the USVI NASA-EPSCoR
Research Infrastructure Development (RID) grant NNX16AL44A.
GCN Circular 25798
Subject
GRB 190919B: BOOTES-5/JGT and BOOTES-3/YA optical observations
Date
2019-09-21T15:04:32Z (6 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
Y.-D. Hu, E. Fernandez-Garcia and A. J. Castro-Tirado (IAA-CSIC), D.
Hiriart and W. H. Lee (UNAM), S. Jeong and I. H. Park (SKKU) and M. D.
Caballero-Garcia (ASU-CAS, CZ), I. Carrasco, C. Perez del Pulgar (Univ.
de Malaga) and R. Querel (NIWA) on behalf of a larger collaboration,
report:
The 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico
Nacional in San Pedro Martir (Mexico) automatically responded in 3.33
hrs to the INTEGRAL trigger of GRB190919B (Mereghetti et al., GCNC
25788). A series of unfiltered images were taken (60s exposure time).
The optical source is detected at the position reported by Bolmer et al.
(GCNC 25789) and Tyurina et al. (GCNC 25791) in the co-added image from
which we derive a magnitude of 19.56 +/- 0.15 at median time of 4.41 h
after the trigger.
Few hours later, the 60cm BOOTES-3/YA robotic telescope at NIWA Lauder
in Otago (New Zealand) also automatically responded to this trigger and
gathered a serie of unfiltered images (60s exposure time). The optical
source still can be detected in the co-added image with a magnitude of f
21.2 +/- 0.4 at a median time of 9.54 hrs after trigger.
These results confirm the fading of the afterglow. The magnitude is
calibrated against the USNO-B1 catalog and is not corrected for Galactic
extinction in the direction of the GRB. Further observations are
ongoing.
We thank the staff at both the Observatorio Astronomico Nacional in San
Pedro Martir and NIWA Lauder for their excellent support.