GRB 201001A
GCN Circular 28538
Subject
GRB 201001A: Fermi GBM Final Real-time Localization
Date
2020-10-01T10:09:20Z (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 09:59:00 UT on 1 Oct 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201001A (trigger 623239145.485614 / 201001416).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 111.3, Dec = 6.5 (J2000 degrees, equivalent to J2000 07h 25m, 6d 30'), with a statistical uncertainty of 3.9 degrees.
The angle from the Fermi LAT boresight is 18.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201001416/quicklook/glg_skymap_all_bn201001416.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/bn201001416/quicklook/glg_healpix_all_bn201001416.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201001416/quicklook/glg_lc_medres34_bn201001416.gif
GCN Circular 28539
Subject
GRB 201001A: Swift detection of a burst
Date
2020-10-01T10:19:55Z (5 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
K. K. Simpson (PSU), J.D. Gropp (PSU), H. A. Krimm (NSF),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:
At 09:58:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 201001A (trigger=998344). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 110.070, -2.210 which is
RA(J2000) = 07h 20m 17s
Dec(J2000) = -02d 12' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single-peaked
structure with a duration of about 30 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger.
The XRT began observing the field at 10:00:47.5 UT, 116.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 110.0806, -2.2103 which
is equivalent to:
RA(J2000) = 07h 20m 19.33s
Dec(J2000) = -02d 12' 37.2"
with an uncertainty of 4.4 arcseconds (radius, 90% containment). This
location is 38 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 https://www.swift.ac.uk/sper. No
spectrum from the promptly downlinked event data is yet available to
determine the column density.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 119 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.12.
Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 AT gmail.com).
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 28540
Subject
GRB 201001A: Enhanced Swift-XRT position
Date
2020-10-01T13:49:40Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1430 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 201001A, 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 = 110.08086, -2.21102 which is equivalent
to:
RA (J2000): 07h 20m 19.41s
Dec (J2000): -02d 12' 39.7"
with an uncertainty of 3.1 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 28542
Subject
GRB 201001A: Fermi GBM observation
Date
2020-10-01T17:53:44Z (5 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres (UAH), A. von Kienlin (MPE) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 09:59:00.49 UT on 1 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201001A (trigger 623239145 / 201001416)
which was also detected by the Swift/BAT (Simpson et al., GCN 28539).
The Fermi GBM Final Real-time Localization (GCN 28538) is consistent
with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 18 degrees.
The GBM light curve shows a single pulse
with a duration (T90) of about 15.6 s (50-300 keV).
The time-averaged spectrum from T0-10.2 s to T0+12.3 s is
best fit by a Band function with Epeak = 71 +/- 21 keV,
alpha = 0.81 +/- 1.11, and beta = -1.91 +/- 0.15.
The event fluence (10-1000 keV) in this time interval is
(9.6 +/- 5.6)E-7 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-2.3 s in the 10-1000 keV band
is 1.7 +/- 0.2 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 28544
Subject
GRB 201001A: Swift-XRT refined Analysis
Date
2020-10-01T18:51:48Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
D.N. Burrows (PSU), J. D. Gropp (PSU), P.A. Evans (U. Leicester), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), T. Sbarrato
(INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), J.A.
Kennea (PSU) and K.K. Simpson report on behalf of the Swift-XRT team:
We have analysed 6.2 ks of XRT data for GRB 201001A (Simpson et al. GCN
Circ. 28539), from 129 s to 24.5 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 28540). The source
is fading with alpha >0.5.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00998344.
This circular is an official product of the Swift-XRT team.
GCN Circular 28545
Subject
GRB 201001A: Swift-BAT refined analysis
Date
2020-10-01T20:46:52Z (5 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), K. K. Simpson (PSU),
M. Stamatikos (OSU), (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 201001A (trigger #998344)
(Simpson, et al., GCN Circ. 28539). The BAT ground-calculated position is
RA, Dec = 110.050, -2.213 deg which is
RA(J2000) = 07h 20m 12.0s
Dec(J2000) = -02d 12' 48.3"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 38%.
The mask-weighted light curve shows a broad single peak of duration roughly
20 seconds, from ~T-5 to ~T+15 sec. T90 (15-350 keV) is 15.2 +- 2.7 sec (estimated
error including systematics).
The time-averaged spectrum from T-4.02 to T+12.98 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
0.96 +- 0.23. The fluence in the 15-150 keV band is 7.6 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+10.79 sec in the 15-150 keV band
is 1.0 +- 0.3 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/998344/BA/
GCN Circular 28548
Subject
GRB 201001A: MITSuME Akeno optical upper limits
Date
2020-10-02T09:42:14Z (5 years ago)
From
Ryohei Hosokawa at Tokyo Institute of Technology <hosokawa@hp.phys.titech.ac.jp>
R. Hosokawa, S. Ogata, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa,
N. Nakamura, N. Ito, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai
(TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 201001A(Fermi GBM Team, GCN 28538; David
et al., GCN 28539) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.
The observation with a series of 60 sec exposures started at
2020-10-01 16:44:38UT. Since some images were heavily affected by the
moon, we stacked the images with good conditions. We did not find any
new point sources within the enhanced Swift/XRT error circle (Evans et
al., GCN 28540) in the 60 sec exposure images and the stacked images.
We obtained the 5-sigma limits of the stacked images as follows.
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
6.8 2020-10-01T19:06:10.46 4020 g'>19.0, Rc>19.3, Ic>18.9
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration. The magnitudes are
expressed in the AB system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al., accepted
for publication in PASJ, https://arxiv.org/abs/2008.11486;
https://github.com/MNiwano/Eclaire).
--
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hosokawa@hp.phys.titech.ac.jp
GCN Circular 28549
Subject
GRB 201001A: Xinglong-2.16m optical upper limit
Date
2020-10-02T13:15:29Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Y. Fu, Z.P. Zhu, X. Liu, D. Xu (NAOC) report:
We observed the field of GRB 201001A (Simpson et al., GCN 28539) using
the Xinglong-2.16m telescope equipped with the BFOSC camera.
Observations were carried out starting at 19:29:17 UT on 2020-10-01
(i.e., about 9.5 hr after the BAT trigger), and 10x180s, 9x360s R-band
frames were obtained.
No optical source is detected in our stacked image at the enhanced XRT
position (Evans et al., GCN 28540), down to a upper limit of R~21.0,
calibrated with the nearby PanSTARRS field.
We acknowledge great support from the Xinglong-2.16m observing staff, in
particular J. Zheng and A.Y. Zhou.
GCN Circular 28550
Subject
GRB 201001A: TSHAO optical upper limit
Date
2020-10-02T14:39:28Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), I. Reva (FAPHI), A. Pozanenko (IKI) report on behalf
of GRB-IKI-FuN:
We observed the field of GRB 201001A (Simpson et al., GCN 28539) with
Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting
on Oct. 01 (UT) 22:56:08.
No optical source is detected within enhanced Swift-XRT position (Evans
et al., GCN 28540). This corresponds to the absence of the source in
earlier optical observations (Simpson et al., GCN 28539; Hosokawa et
al., GCN 28548; Fu et al., GCN 28549). Preliminary photometry of the
field is following.
Date UT start t-T0 Filter Exp. OT Err. UL(3 sigma)
(mid, days) (s)
2020-10-01 22:56:08 0.54732 R 22*50 n/d n/d 20.3
The photometry is based on nearby USNO-B1.0 star.
USNO-B1.0_id R2
0877-0204059 15.98
GCN Circular 28555
Subject
GRB 201001A: Swift/UVOT Upper Limits
Date
2020-10-03T19:24:16Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
A. Belles (PSU) and K. K. Simpson (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 201001A
120 s after the BAT trigger (Simpson et al., GCN Circ. 28539).
No optical afterglow consistent with the XRT position
(Simpson et al. GCN Circ. 28539)
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 120 270 147 >21.1
u_FC 279 529 246 >19.8
white 120 1525 392 >21.1
v 611 1575 117 >18.8
b 535 1501 97 >18.9
u 279 1476 324 >19.8
w1 660 1452 97 >19.1
m2 635 1427 97 >19.7
w2 586 1550 117 >19.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).