GRB 211211A
GCN Circular 31299
Subject
GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
Date
2021-12-24T16:40:23Z (4 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Rahul Gupta, S. B. Pandey, A. Ror, A. Kumar, A. Aryan, Dimple, A. Ghosh, B.
Kumar, and K. Misra (ARIES) as a part of larger international collaboration:
We performed late-time photometric observations of the optical afterglow (Zheng
and Filipenko GCN 31203) of Fermi (Fermi GBM team, GCN 31201) and Swift (D'Ai
et al., GCN 31202) detected GRB 211211A using the 4Kx4K CCD Imager (Pandey
et al. 2017, arXiv:1711.05422v1) mounted at the axial port of the 3.6m
Devasthal Optical Telescope of ARIES Nainital at multiple epochs in several
filters. We report the preliminary brightness of the afterglow to be R =
21.66 +/- 0.07 mag ~ 1.41 days after the GBM trigger. At successive epochs,
we obtained the limiting mag of 23.7 mag ~ 4.42 days post-burst. Our
observations are consistent with the rapid decay nature of the afterglow
reported by de Ugarte Postigo et al. GCN 31229 and A. Moskvitin et al. GCN
31234.
The magnitude value reported is calibrated against UNSO B1 nearby stars.
This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is
the recently commissioned facility in the Northern Himalayan region of
India (long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the
Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (
https://www.aries.res.in). Authors of this GCN circular thankfully
acknowledge consistent support from the staff members to run and maintain
the 3.6m DOT.
GCN Circular 31264
Subject
GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
Date
2021-12-18T21:26:07Z (4 years ago)
From
Wen-fai Fong at Northwestern U <wfong@northwestern.edu>
J. Rastinejad, W. Fong (Northwestern), A. J. Levan, D. B. Malesani (Radboud), J. Jencson, D. Sand (U. Arizona), N. R. Tanvir (Leicester) report:
We observed the location of GRB 211211A (D���Ai et al., GCN 31202) with the MMT and Magellan Infrared Spectrograph (MMIRS) instrument mounted on the MMT 6.5-meter telescope on Mount Hopkins, Arizona. At a mid-time of 2021 December 18.52 UT (~6.9 days post-burst), we obtained 126 x 30 s of K-band imaging at a median airmass of 1.5 and seeing of 0.8 arcsec. A faint K-band source is still detected at the location of the optical afterglow (first reported by Zheng & Fillipenko; GCN 31203). Based on calibration to 2MASS, we estimate a preliminary magnitude for the source of K_AB ~ 24 mag, although we caution that the faintness of the source precludes a precise measure at this time. Visual inspection relative to our Gemini K-band imaging (Levan et al. GCN 31235) is in support of clear fading of the source.
Taken at face value, the K-band source has declined by ~1.5 mag between ~4 and 7 days post-burst, while AT2017gfo only faded by ~0.4 mag in the K band (Villar et al., 2017, ApJL, 851, L21) on these same timescales.
Further observations are planned. We thank Joannah Hinz and ShiAnne Kattner at MMT for the rapid planning and execution of these observations.
GCN Circular 31242
Subject
GRB 211211A: TNG NIR observations
Date
2021-12-16T12:40:41Z (4 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D'Avanzo (INAF-OAB), A. Rossi (INAF-OAS), D. B. Malesani (Radboud), V. D'Elia (ASI-SSDC), A. Melandri (INAF-OAB),
M. De Pasquale (Univ. Messina), S. Piranomonte (INAF-OAR), G. Andreuzzi, A. Garcia de Gurtubai (INAF-TNG)
on behalf of the CIBO collaboration report:
We observed the field of GRB 211211A (D���Ai et al., GCN Circ. 31202) with the Italian 3.6m TNG telescope equipped with the
near-infrared camera NICS. A series of images were obtained with the H filter on 2021-12-16 from 05:51:36 UT to 07:00:51 UT
(i.e. at a mid time of about 4.7 days after the burst).
No source is detected at the optical and NIR counterpart position (Zheng & Filippenko, GCN Circ. 31203; Levan et al., GCN Circ.
31235) down to the following 3sigma upper limit:
H > 20.5 (Vega) or H > 21.9 (AB)
(calibrated against the 2MASS catalogue).
GCN Circular 31236
Subject
GRB 211211A: Insight-HXMT/HE detection
Date
2021-12-16T06:44:10Z (4 years ago)
From
Y Q Zhang at IHEP <yqzhang@ihep.ac.cn>
Y. Q. Zhang, S. L. Xiong, X. B. Li, C. Cai, Q. Luo, S. Xiao,
J. C. Liu, W. C. Xue, Q. B. Yi, C. Zheng���Y. Huang, C. K. Li,
G. Li, J. Y. Liao, X. Y. Song, 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 2021-12-11T13:09:59.500 (T0), Insight-HXMT/HE detected
GRB 211211A (trigger ID: HEB211211548) in a routine search of the data,
which also triggered Fermi/GBM (Fermi GBM Team, GCN #31201),
Swift/BAT (D'Ai A. et al., GCN #31202),
CALET (Tamura T. et al., GCN #31226) and
INTEGRAL/SPI-ACS (Minaev P. et al., GCN #31230)
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB211211548_lc.jpg
It should be noted that there is a significant saturation effect (data loss)
during bright parts of this GRB in HXMT.
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 31235
Subject
GRB 211211A - Gemini K-band detection
Date
2021-12-15T21:19:50Z (4 years ago)
From
Andrew Levan at U.of Leicester <a.levan@astro.ru.nl>
A.J. Levan (Radboud), J. Rastinejad (Northwestern), B. Gompertz (Birmingham), W. Fong (Northwestern), D. B. Malesani (Radboud), M. Nicholl (Birmingham) report for a larger collaboration:
���We obtained K-band observations of GRB 211211A (D���Ai et al., GCN 31202) with the Gemini-North Telescope and NIRI. Observations began at 14:40 UT on 15 Dec 2021 (~4 days after the GRB). A total of 900 s of exposure were obtained.
At the location of the afterglow identified by Zheng & Fillipenko (GCN 31203) we clearly detect a K-band source. Photometry is complicated by the narrow field of view, however, using the 2MASS source at RA, DEC(J2000)=14:09:08,86, 27:53:54.4 with a magnitude of K=12.8, we determine an afterglow magnitude of K = 20.5 +/- 0.1 (Vega) or 22.4 +/- 0.1 (AB). This magnitude is substantially brighter than expected for afterglow emission given the rapid decay observed in the i-band (de Ugarte Postigo et al., GCN 31229), and the relatively blue colours and spectra of the source at earlier times (Malesani et al., GCN 31221; Belles & D���Ai, GCN 31222).
The rapid fading and relative faintness in the optical apparently rules out a classical long-GRB at z = 0.076, since a supernova akin to those seen in long GRBs at this epoch would have i ~ 20, 4 magnitudes brighter than observed by de Ugarte Postigo et al. (GCN 31229). Alternatively, the prompt light curve appears to show some similarities with GRB 060614, another suggested short-GRB with extended emission (Gehrels et al. 2006 Nature 444 1044). If GRB 211211A is associated with a compact object merger, its large offset relative to the putative host at z = 0.076 may be expected. The absolute magnitude of the source seen in the K-band is -15.2 (AB), comparable to that of AT2017gfo at the same epoch. Hence, while it remains possible that GRB 211211A is a higher redshift event in chance projection with a low redshift galaxy, a compact binary merger at z=0.076 provides a good explanation of the galactic location, rapid optical fading and red colour of the source.
We thank the Gemini staff for the rapid execution of these observations."
GCN Circular 31234
Subject
GRB 211211A: SAO RAS optical observations
Date
2021-12-15T17:28:29Z (4 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO), O. Spiridonova (SAO), S. Belkin (IKI),
A. Pozanenko (IKI), N. Pankov (HSE, IKI) report
on behalf of GRB IKI FuN:
We observed the field of GRB 211211A (Fermi team GCN 31201,
D'Ai et al. GCN 31202; Mangan et al. GCN 31210; Tamura et al.
GCN 31226) with Zeiss-1000 telescope of SAO RAS in Rc-filter
on 2021.12.14 (UT) 02:03:33.
We marginally detected an afterglow (Zheng and Filippenko GCN 31203;
Jiang et al. GCN 31213; Strausbaugh et al. GCN 31214; Ito et al.
GCN 31217; de Ugarte Postigo et al. GCN 31218,31228,31229; Malesani et
al. GCN 31221; Belles et al. GCN 31222; Kumar et al. GCN 31227; Pankov
et al. GCN 31233).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-12-14 02:03:33 2.55803 Rc 6*600 23.2 S/N=2.5 23.1
The photometry is based on the nearby SDSS stars:
SDSS-DR12
RA DEC R(Lupton transformations)
14:09:08.84 +27:53:54.56 15.833
14:09:04.53 +27:54:10.48 16.701
14:08:57.03 +27:54:50.26 17.677
14:08:57.88 +27:55:06.09 17.805
14:09:03.81 +27:55:56.55 17.104
14:09:07.89 +27:55:44.00 18.640
The light curve based on published photometry can be found in
http://grb.rssi.ru/GRB211211A/GRB211211A_LC.png
Using R-photometry we found a single power law decay index of -1.5
between 0.4 and 2.6 days after the burst trigger. However the power
law index between 1.6 days (Pankov et al. GCN 31233) and 2.6 days
(this circ.) we may assume power law index of -3.25 which confirm
very fast decay in i-filter observed by CAFOS/2.2mCAHA
(de Ugarte Postigo et al. GCN 31229). Based on a typical power law
decay of afterglows we may suggest a bump in the LC at ~ 2.5 days
followed by a power law decay index of 1.5.
GCN Circular 31233
Subject
GRB 211211A: AbAO optical observations
Date
2021-12-15T15:44:10Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE, IKI), A. Pozanenko (IKI), S. Belkin (IKI), R. Ya.
Inasaridze (AbAO), D. Datashvili (AbAO), V. R. Ayvazian (AbAO), G. V.
Kapanadze (AbAO) report on behalf of GRB IKI FuN:
We observed the field of GRB 211211A (Fermi team GCN 31201, D'Ai et al.
GCN 31202; Mangan et al. GCN 31210; Tamura et al. GCN 31226) with AS-32
telescope of Abastumani observatory (AbAO) in R-filter on 2021-12-13
(UT) 02:21:44 and 2021-12-14 (UT) 01:49:33.
In the first epoch we marginally detected an afterglow (Zheng and
Filippenko GCN 31203; Jiang et al. GCN 31213; Strausbaugh et al. GCN
31214; Ito et al. GCN 31217; de Ugarte Postigo et al. GCN
31218,31228,31229; Malesani et al. GCN 31221; Belles et al. GCN 31222;
Kumar et al. GCN 31227). In the second epoch we obtained only an upper
limit.
Preliminary photometry of the field is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-12-13 02:21:44 1.56233 R 36*60 21.6 S/N=3 21.6
2021-12-14 01:49:33 2.52748 R 43*60 n/d n/d 21.8
The photometry is based on the nearby SDSS stars:
SDSS-DR12
RA DEC R(Lupton transfoemations)
14:09:08.84448 +27:53:54.5604 15.833
14:09:04.53240 +27:54:10.4760 16.701
14:08:57.03480 +27:54:50.2632 17.677
14:08:57.87816 +27:55:06.0924 17.805
14:09:03.80928 +27:55:56.5464 17.104
14:09:07.89072 +27:55:43.9968 18.640
GCN Circular 31232
Subject
GRB 211211A: GMG upper limit
Date
2021-12-15T02:00:51Z (4 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao_obs@ynao.ac.cn>
J. Mao, Y.-X. Xin, and J.-M. Bai (YNAO) report:
We observed the field of GRB 211211A (D'Ai et al. GCN 31202) by the GMG telescope in Yunnan observatories.
The observation began from UT 22:41:02 Dec 12, 2021, about 33.5 hours from the trigger. We could not observe
the optical afterglow down to a magnitude limit of r~22.0.
GCN Circular 31230
Subject
GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
Date
2021-12-14T17:35:39Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
P. Minaev (IKI), A. Pozanenko (IKI) report on behalf of GRB IKI FuN:
We analyzed GRB 211211A (D'Ai et al. GCN 31202; Mangan et al. GCN 31210;
Tamura et al. GCN 31226) using publicly available data of GBM/Fermi and
SPI-ACS/INTEGRAL. Using GBM/Fermi we estimate a duration in 7 - 850 keV
energy band T_90 = 50.6 +/- 0.1 s, while the emission is seen at least
up to 130 s after the trigger. We performed spectral analysis in time
interval of (-0.5, 60) s, covering the main part of GRB activity. The
best fit is obtained for (Band model + thermal component) with following
parameters: E_p = 758 +/- 13 keV, alpha = -1.21 +/- 0.01, beta = -2.54
+/- 0.03 and thermal spectral component with kT = 13.9 +/- 0.3 keV. The
fluence of F = (5.47 +/- 0.01)E-4 erg/cm**2 is obtained in 10 - 1000 keV
energy band. The parameter E_p = 758 +/- 13 keV is higher than
preliminary value presented by GBM team (Mangan et al., GCN 31210) due
to inclusion of the thermal component in the fit.
Assuming a redshift of z = 0.076 (Malesani et al., GCN 31221) we
estimated E_iso = (1.161 +/- 0.006)E52 erg in the 1 keV - 10 MeV energy
band. The burst is placed very close but outside the 2 sigma correlation
region at E_p,i - E_iso and T_90,i - EH diagrams [1,2], see the Figures in
http://grb.rssi.ru/GRB211211A/GRB211211A_Ep-Eiso-2.png
http://grb.rssi.ru/GRB211211A/GRB211211A_EHD.png
Using T_90,i - EH diagram we found minimal possible redshift value of z
= 0.080, very close to the redshift of z = 0.076 (Malesani et al., GCN
31221). Therefore, we consider GRB 211211A as not a significant outlier.
The burst was also detected by SPI-ACS/INTEGRAL. Its duration in the
SPI-ACS energy band (> 80 keV) is T_90 = 30.0 +/- 0.2 s, while the
emission is seen up to 70 s. Comparing fluences of long-duration GRBs
simultaneously recorded by SPI-ACS and Fermi/GBM (Chelovekov et al., in
preparation) we estimated the GRB 211211A fluence to be 5.5E-4 erg/cm**2
in the 10-1000 keV energy band (the 95% confidence region 1.6-4 ��� 1.9E-3
erg/cm**2, incl. systematics). GRB 211211A is one of the brightest GRBs
of SPI-ACS/INTEGRAL sample in terms of peak flux (about 40000 cnts/50
ms). The SPI-ACS light curve of GRB 211211A can be found in
http://grb.rssi.ru/GRB211211A/GRB211211A_SPI-ACS_lc-2.png
[1] - Minaev et al., MNRAS, 492, 1919, 2020
[2] - Minaev et al., Astronomy Letters, 46, 9, 573, 2020
GCN Circular 31229
Subject
GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
Date
2021-12-14T16:25:45Z (4 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene,
J.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC), I. Vico and
A. Guijarro (CAHA) report:
We obtained further i-band imaging of the afterglow of GRB 211211A
(Fermi team GCN31201; D���Ai et al. GCN31202; Zheng and Filipenko
GCN 31203) from CAFOS/2.2m CAHA 2.66 days after the burst onset.
The observation consisted of 20x120s exposures under good seeing
and yielded a faint detection. The light curve decay, compared to our
previous observation from Calar Alto (de Ugarte Postigo et al., GCN
31228) indicates an extreme decay index of alpha = 3.25+/-0.40.
This is similar to what is observed from the XRT light curve, which
currently decays with an index of 3.2 (-0.7,+0.8)
(https://www.swift.ac.uk/xrt_live_cat/01088940/ <https://www.swift.ac.uk/xrt_live_cat/01088940/>; Evans et al. 2007;
Evans et al. 2009). We note that this is amongst the fastest post-break
decays that are normally observed for GRB afterglows.
Further observations with larger telescopes are encouraged.
GCN Circular 31228
Subject
GRB 211211A: Further observations from CAFOS/2.2m CAHA
Date
2021-12-13T17:22:44Z (4 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene,
J.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC), I. Vico and
A. Guijarro (CAHA) report:
We obtained a second imaging observation of the optical afterglow
of GRB 211211A (Fermi team GCN31201