GRB 190320A
GCN Circular 23973
Subject
GRB 190320A: Swift detection of a burst
Date
2019-03-20T01:47:01Z (6 years ago)
From
Boris Sbarufatti at PSU <bxs60@psu.edu>
J.D. Gropp (PSU), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
M. J. Moss (George Washington University), T. Sakamoto (AGU),
B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:
At 01:14:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 190320A (trigger=893808). Swift did not slew immediately
due to an observing constraint. The BAT on-board calculated location is
RA, Dec 117.811, -45.890 which is
RA(J2000) = 07h 51m 15s
Dec(J2000) = -45d 53' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). There is a data gap from ~T+10 s to ~T+100 s,
and the available data show no significant structure. However,
since the image significance is 7.63 sigma, and the trigger is
temporally (within ~ 20 sec) coincident with the Fermi/GBM event
(trignum=574737261), we believe this is likely to be a real GRB.
Due to an observing constraint, Swift will not slew until T0+44.3
minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular 23974
Subject
GRB 190320A: Swift-XRT observations
Date
2019-03-20T03:03:49Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.A. Kennea (PSU), G. Cusumano (INAF-IASF PA), M. Perri (ASDC), P.A.
Evans (U. Leicester), J.P. Osborne (U. Leicester) and D.N. Burrows
(PSU) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 190320A at 02:01:48.5 UT,
2831.9 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 117.84887,
-45.88801 which is equivalent to:
RA(J2000) = 07h 51m 23.73s
Dec(J2000) = -45d 53' 16.8"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 95 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density.
GCN Circular 23976
Subject
GRB190320A: MASTER OT detection
Date
2019-03-20T06:47:29Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov,
A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova, Yu.Ishmuhametova, S.Yazev (Applied Physics Institute, Irkutsk State University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE, SJNU)
MASTER-OAFA automatically pointed to Swift GRB 190320A (Kennea et al. GCN
23974, Gropp et al. GCN 23973, Lipunov et al. GCN 23975)
detected MASTER OT J075123.56-455316.54
at position
RA,Dec(2000)=07h 51m 23.56s , -45d 53m 16.54s
Preliminary photometry is
2019-03-20 01:15:58.049 17.2
2019-03-20 01:19:25.483 17.4
GCN Circular 23977
Subject
GRB 190320A: Enhanced Swift-XRT position
Date
2019-03-20T07:52:54Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 303 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 190320A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 117.84813, -45.88785 which is equivalent
to:
RA (J2000): 07h 51m 23.55s
Dec (J2000): -45d 53' 16.3"
with an uncertainty of 4.5 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 23978
Subject
GRB 190320A: Fermi GBM observation
Date
2019-03-20T09:00:55Z (6 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE), S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 01:14:16.49 UT on 20 March 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190320A (trigger 574737261 / 190320052),
which was also detected by the Swift/BAT (Gropp et al. 2008, GCN 23973).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 59.7 degrees.
The GBM light curve shows a structured pulse with a
duration (T90) of about 43 s (50-300 keV).
The time-averaged spectrum from T0-4.096 s to T0+32.769 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.75 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 314 +/- 35 keV
The event fluence (10-1000 keV) in this time interval is
(6.7 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+29.44 s in the 10-1000 keV band
is 1.93 +/- 0.17 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 296 +/- 51 keV, alpha = -0.74 +/- 0.09 and beta = -2.2 +/- 0.4.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
[GCN OPS NOTE(20mar19): Per author's request, the extra zero was removed
from the GRB name (in the title and the body): "1903020A" --> "190320A".]
GCN Circular 23979
Subject
GRB190320A: MASTER GRB counterpart decay
Date
2019-03-20T09:06:20Z (6 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov,
A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE, SJNU)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova, Yu.Ishmuhametova, S.Yazev (Applied Physics Institute, Irkutsk State University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Stationof the Pulkovo Observatory),
MASTER-OAFA robotic telescope (Global MASTER-Net http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,vol. 2010, 30L)
located in Argentina (OAFA observatory of San JuanNational University)
was pointed to the Swift GRB190320A (Kennea et al. GCN 23974, Gropp et al. GCN 23973, Lipunov et al. GCN 23975)
21 sec after notice time (82 sec after trigger time) at 2019-03-20 01:15:58 UT (Lipunov et al. GCN 23975)
MASTER-OAFA find a new object MASTER OT J075123.56-455316.54 (Lipunov et al. GCN 23976)
within Swift GRB 190320A error box (Kennea et al. GCN 23976, Osborne et al. GCN23977)
at position RA,Dec(2000)=07h 51m 23.56s , -45d 53m 16.54s (+-0.7")
MASTER OT J075123.56-455316.54 decay by 1 magnitude during several minutes.
The reduction is continued.
GCN Circular 23980
Subject
GRB 190320A: Swift-BAT refined analysis
Date
2019-03-20T11:41:19Z (6 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
J.D. Gropp (PSU), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 190320A (trigger #893808)
(Gropp, et al., GCN Circ.23973). The BAT ground-calculated position is
RA, Dec = 117.824, -45.876 deg which is
RA(J2000) = 07h 51m 17.8s
Dec(J2000) = -45d 52' 33.3"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 29%.
The mask-weighted light curve shows a single episode with some superimposed
structure from roughly T-25 to T+40 sec. The spacecraft slewed away from the
burst position at around T+500 sec. T90 (15-350 keV) is 64.0 +- 12.1 sec
(estimated error including systematics).
The time-averaged spectrum from T-27.20 to T+44.80 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.20 +- 0.20. The fluence in the 15-150 keV band is 2.7 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band
is 1.3 +- 0.5 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/893808/BA/
GCN Circular 23981
Subject
GRB 190320A: Swift-XRT refined Analysis
Date
2019-03-20T11:55:11Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J.
LaPorte (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester)
and J.D. Gropp report on behalf of the Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 190320A (Gropp et al. GCN
Circ. 23973), from 2.8 ks to 22.2 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Osborne et al. (GCN Circ. 23977).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.26 (+0.17, -0.16).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.06 (+0.33, -0.21). The
best-fitting absorption column is 3.33 (+1.48, -0.19) x 10^21 cm^-2,
consistent with the Galactic value of 3.1 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.6 x 10^-11 (5.7 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.33 (+1.48, -0.19) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 2.06 (+0.33, -0.21)
If the light curve continues to decay with a power-law decay index of
1.26, the count rate at T+24 hours will be 2.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.5 x
10^-14 (1.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00893808.
This circular is an official product of the Swift-XRT team.
GCN Circular 23982
Subject
GRB 190320A: Swift/UVOT Upper Limits
Date
2019-03-20T16:22:03Z (6 years ago)
From
Frank Marshall at Swift/UVOT <marshall@milkyway.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190320A
2834 s after the BAT trigger (Gropp et al., GCN Circ. 23973).
No optical afterglow consistent with the XRT position
(Lipunov et al. GCN Circ. 23976)
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
white_FC 2834 2984 147 >20.0
white 2834 16112 1213 >21.4
v 2992 21862 1645 >20.4
b 3812 15216 1082 >20.8
u 3607 3807 197 >19.6
w1 3402 3602 197 >19.5
m2 3196 22200 524 >19.8
w2 4223 20949 1776 >20.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.23 in the direction of the burst
(Schlegel et al. 1998).