GRB 220107A
GCN Circular 31399
Subject
GRB 220107A: Fermi GBM Final Real-time Localization
Date
2022-01-07T14:55:38Z (3 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 14:45:31 UT on 7 Jan 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220107A (trigger 663259536.927164 / 220107615).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 168.2, Dec = 35.0 (J2000 degrees, equivalent to J2000 11h 12m, 35d 00'), with a statistical uncertainty of 1.2 degrees.
The angle from the Fermi LAT boresight is 77.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220107615/quicklook/glg_skymap_all_bn220107615.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220107615/quicklook/glg_healpix_all_bn220107615.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220107615/quicklook/glg_lc_medres34_bn220107615.gif
GCN Circular 31400
Subject
GRB 220107A: BALROG localization (Fermi Trigger 663259536 / GRB 220107615)
Date
2022-01-07T15:05:36Z (3 years ago)
From
Jochen Greiner at MPE,Garching <jcg@mpe.mpg.de>
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
663259536 at 14:45:31 on 07 Jan. 2022 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 168.5+/-1.4 deg
Decl.(2000.0) = 34.9+/-1.0 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB220107615/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB220107615/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB220107615/json
GCN Circular 31402
Subject
GRB 220107A: Swift/BAT-GUANO arcminute localization
Date
2022-01-07T20:07:49Z (3 years ago)
From
Aaron Tohuvavohu at U Toronto <aaron.tohu@gmail.com>
James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:
Swift/BAT did not localize GRB 220107A onboard (T0:
2022-01-07T14:45:31 UTC, Fermi/GBM GCN 31399), due to a slew.
The Fermi notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.
The burst is detected in BAT, on the approach to SAA and during a slew.
The location was found in a mosaiced slew image with an SNR ~9.
The BAT position is
RA, Dec = 169.761, 34.139 deg which is
RA(J2000) = 11h 19m 02.58s
Dec(J2000) = 34d 08��� 19.26���
with an estimated uncertainty of 10 arcmin.
The position is consistent with the Fermi/GBM RoboBA (GCN 31399) and
BALROG (GCN 31400) localizations.
XRT and UVOT follow-up has been requested.
Results of follow-up observations will be reported in future circulars.
GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/
GCN Circular 31403
Subject
Fermi GRB 220107A: Global MASTER-Net observations report
Date
2022-01-07T20:15:25Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov,
D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina,
A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev
(Irkutsk State University, API),
B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez,
M.L.H.Rodriguez (INAOE, OAGH)
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 220107A ( Fermi GBM team, GCN 31399) errorbox 14945 sec after notice time and 14974 sec after trigger time at 2022-01-07 18:55:06 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 73 deg. The sun altitude is -48.3 deg.
The galactic latitude b = 68 deg., longitude l = 187 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1841973
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
15004 | 2022-01-07 18:55:06 | MASTER-Tavrida | (11h 04m 15.78s , +35d 40m 05.4s) | C | 60 | 13.2 |
15163 | 2022-01-07 18:57:45 | MASTER-Tavrida | (11h 07m 37.93s , +33d 44m 04.2s) | C | 60 | 12.8 |
15243 | 2022-01-07 18:59:04 | MASTER-Tavrida | (11h 17m 11.22s , +33d 45m 44.4s) | C | 60 | 13.6 |
18102 | 2022-01-07 19:46:44 | MASTER-Tavrida | (11h 11m 38.28s , +37d 34m 23.5s) | C | 60 | 18.0 |
18182 | 2022-01-07 19:48:03 | MASTER-Tavrida | (11h 04m 13.64s , +35d 40m 14.4s) | C | 60 | 17.5 |
18261 | 2022-01-07 19:49:23 | MASTER-Tavrida | (11h 14m 10.15s , +35d 39m 14.1s) | C | 60 | 18.0 |
18341 | 2022-01-07 19:50:42 | MASTER-Tavrida | (11h 07m 30.05s , +33d 44m 06.6s) | C | 60 | 18.2 |
18421 | 2022-01-07 19:52:02 | MASTER-Tavrida | (11h 17m 13.08s , +33d 44m 18.7s) | C | 60 | 16.7 |
18581 | 2022-01-07 19:54:42 | MASTER-Tavrida | (11h 23m 01.66s , +35d 39m 47.5s) | C | 60 | 13.3 |
19251 | 2022-01-07 20:05:52 | MASTER-Tavrida | (11h 11m 42.85s , +37d 33m 19.8s) | C | 60 | 18.6 |
19330 | 2022-01-07 20:07:11 | MASTER-Tavrida | (11h 04m 17.45s , +35d 38m 35.9s) | C | 60 | 17.6 |
19409 | 2022-01-07 20:08:31 | MASTER-Tavrida | (11h 14m 05.38s , +35d 40m 09.3s) | C | 60 | 18.0 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 31404
Subject
GRB 220107A: Swift ToO observations
Date
2022-01-07T22:10:20Z (3 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 Swift/BAT-GUANO GRB 220107A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021476
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 Swift/BAT-GUANO 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 31406
Subject
GRB 220107A: Fermi GBM observations
Date
2022-01-08T03:49:49Z (3 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
P. Veres and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:
"At 14:45:31.93 UT on 7 January 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220107A (trigger 663259536 / 220107615),
which was also detected by the Swift/BAT-GUANO (DeLaunay et al., GCN 31402).
The Fermi GBM Final Real-time Localization (GCN 31399) is consistent
with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 78 degrees.
The GBM light curve shows multiple peaks
with a duration (T90) of about 33 s (50-300 keV).
The time-averaged spectrum from T0-0.3 s to T0+36.6 s is
best fit by a Band function with Epeak = 168 +/- 11 keV,
alpha = -0.55 +/- 0.06, and beta = -1.94 +/- 0.06.
The event fluence (10-1000 keV) in this time interval is
(2.24 +/- 0.05)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 + 10.2 s in the 10-1000 keV band
is 13.9 +/- 0.3 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 31408
Subject
GRB 220107A: AstroSat CZTI detection
Date
2022-01-08T05:33:42Z (3 years ago)
From
Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>
A. Suresh (IITB), G. Waratkar (IITB), V. Prasad (IUCAA), A. Vibhute
(IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao
(IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat
CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al.,
2021, JApA, 42, 73) showed detection of a long GRB 220107A, which was
also detected by Fermi-GBM (GCN 31399, 31406), and Swift/BAT-GUANO
(Tohuvavohu et al., GCN 31402) with BALROG localization (Greiner et al.
GCN 31400).
The source was clearly detected in the 20-200 keV energy range. The
light curve showed multiple peaks of emission with the strongest peak at
2022-01-07 14:46:59.50 UT. The measured peak count rate associated with
the burst is 382 (+36 -38) cts/s above the background in the combined
data of four quadrants, with a total of 4724 (+364 -472) cts. The local
mean background count rate was 149 (+1 -1) cts/s. Using cumulative
rates, we measure a T90 of 97 (+4 -5) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector
in the 100-500 keV energy range. The light curve showed multiple peaks
of emission with the strongest peak at 2022-01-07 14:46:57.70 UT. The
measured peak count rate is 1451 (+86 -94) cts/s above the background in
the combined Veto data of four quadrants, with a total of 13589 (+1062
-1220) cts. The local mean background count rate was 1500 (+4 -4) cts/s.
We measure a T90 of 87 (+2 -2) s from the cumulative Veto light curve.
CZTI GRB detections are reported regularly on the payload site at
http://astrosat.iucaa.in/czti/?q=grb [1]. CZTI is built by a TIFR-led
consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC,
and PRL. The Indian Space Research Organisation funded, managed, and
facilitated the project.
Links:
------
[1] http://astrosat.iucaa.in/czti/?q=grb
GCN Circular 31410
Subject
GRB 220107A: Swift-XRT afterglow detection
Date
2022-01-08T06:39:25Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB), 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
Swift/BAT-GUANO-detected burst GRB 220107A (DeLaunay et al. GCN Circ.
31402), collecting 699 s of Photon Counting (PC) mode data between
T0+26.7 ks and T0+27.4 ks.
An uncatalogued X-ray source is detected and is above the RASS 3-sigma
upper limit at this position, and is therefore likely the GRB
afterglow. Using 698 s of PC mode data and 1 UVOT image, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 169.80648, +34.17014
which is equivalent to:
RA (J2000): 11h 19m 13.55s
Dec(J2000): +34d 10' 12.5"
with an uncertainty of 2.3 arcsec (radius, 90% confidence). This
position is 3.0 arcmin from the Swift/BAT-GUANO position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=2.5 (+0.5, -2.4).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.84 (+0.27, -0.18). The
best-fitting absorption column is 3.1 (+6.1, -0.9) x 10^20 cm^-2,
consistent with the Galactic value of 2.2 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.5 x 10^-11 (3.7 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.1 (+6.1, -0.9) x 10^20 cm^-2
Galactic foreground: 2.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.84 (+0.27, -0.18)
If the light curve continues to decay with a power-law decay index of
2.5, the count rate at T+24 hours will be 0.054 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x
10^-12 (2.0 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021476.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021476.
This circular is an official product of the Swift-XRT team.
GCN Circular 31413
Subject
GRB 220107A: MITSuME Akeno optical observation
Date
2022-01-08T14:40:52Z (3 years ago)
From
Ryohei Hosokawa at Tokyo Institute of Technology <hosokawa@hp.phys.titech.ac.jp>
R. Hosokawa, Y. Imai, M. Niwano, K. L. Murata, N. Ito, Y. Takamatsu,
M. Takaku, R. Noto, S. Sato, R. Yamaguchi, Y. Yatsu, and N. Kawai
(TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 220107A (The Fermi GBM team et al. GCN
Circular #31399, F. Kunzweiler et al. GCN Circular #31400, James
DeLaunay et al. GCN Circular #31402, V. Lipunov et al. GCN Circular
#31403, P. A. Evans et al. GCN Circular #31404, P. Veres et al. GCN
Circular #31406, A. Suresh et al. GCN Circular #31408, D.N. Burrows et
al. GCN Circular #31410) with the optical three color (g', Rc, and Ic)
CCD cameras attached to the MITSuME 50 cm telescope Akeno. The
observation with a series of 60 sec exposures was carried out from
2022-01-07 20:21:55 UT (~5.6 hours after the Fermi GBM trigger). We
stacked the images with good conditions.
Our observation covered 100% of the Swift/BAT-GUANO error region
(James DeLaunay et al. GCN Circular #31402). Comparing our co-added
images with the GSC2.3 and PS1 catalog, we marginally detected one
uncatalogued source at RA, Dec = (169.80774, 34.17079), which is
equivalent to:
RA (J2000): 11h19m13.859s
Dec(J2000): +34d 10' 14.845"
This position is 4.4 arcsec from the center of Swift XRT position
(D.N. Burrows et al. GCN Circular #31410).
The magnitudes of the source are as follows.
T0+[hour] | MID-UT | T-EXP[sec] | candidate magnitude | 5-sigma limits
------------------------------------------------------------------------------------------------
5.4 | 2022-01-07 20:55:27 | 1620 | g'=19.8 +/- 0.5, Rc=18.9 +/- 0.2,
Ic=18.3 +/- 0.2 | g'>20.9, Rc>21.0, Ic>20.3
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used PS1 catalog for flux calibration. The conversion from PS1 r
and i band to our Rc and Ic band is by the equation of Tonry et al.
(2012), Table. 6. The magnitudes are expressed in the AB system. The
images were processed in real-time through the MITSuME GPU reduction
pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24;
https://github.com/MNiwano/Eclaire).
GCN Circular 31415
Subject
GRB 220107A: Swift/UVOT Detection
Date
2022-01-09T00:24:42Z (3 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) reports on behalf of the Swift UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220107A 26.7 ks after
the Fermi detection (GCN Circ. 31399). An uncatalogued fading source consistent with
the GUANO localization (DeLaunay et al., GCN Circ. 31402) and the XRT position
(Burrows et al., GCN Circ. 31410) is detected in the initial UVOT exposures.
This appears consistent with the optical transient reported by Hosokawa et al.
(GCN Circ. 31413).
The preliminary UVOT position is:
RA (J2000) = 11:19:13.71 = 169.80713 (deg.)
Dec (J2000) = +34:10:14.5 = 34.17070 (deg.)
with an estimated uncertainty of 0.4 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:
Filter T_start(ks) T_stop(ks) Exp(s) Mag
white 26.7 28.5 1834 20.16 +/- 0.08
white 32.4 33.0 2708 20.35 +/- 0.07
white 37.6 39.4 247 20.43 +/- 0.24
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.056 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 31416
Subject
GRB 220107A: Nanshan/NEXT optical observations
Date
2022-01-09T03:07:24Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu (NAOC,HUST), S.Q. Jiang, S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220107A detected by Fermi (the Fermi/GBM
team, GCN Circ. 31399, Kunzweiler et al. GCN Circ. 31400) and Swift
(DeLaunay et al. GCN Circ. 31402), using the NEXT-0.6m telescope located
at Nanshan, Xinjiang, China. Observations started at 19:46:36 UT on
2022-01-08 (i.e., 29.46 hrs after the Fermi GBM trigger), and 10x300 s
frames were obtained in the Sloan r-filter.
The previously reported optical afterglow (Hosokawa et al. GCN Circ.
31413, Siegel et al. GCN Circ. 31415) is clearly detected in our stacked
image, and has decayed to r = 20.22 +/- 0.05, calibrated by nearby SDSS
stars.
GCN Circular 31419
Subject
GRB 220107A: AbAO and Terskol optical observations
Date
2022-01-09T12:27:19Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (IKI), S. Belkin (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze
(AbAO), V. Agletdinov (KIAM), V. R. Ayvazian (AbAO), D. Datashvili
(AbAO), G. V. Kapanadze (AbAO) report on behalf of GRB IKI FuN:
We observed the field of GRB 220107A till now detected by GBM/Fermi (the
Fermi/GBM team, GCN 1399; Kunzweiler et al. GCN 31400) and Swift
(DeLaunay et al. GCN 31402) with AS-32 telescope of Abastumani
observatory (AbAO) and K-800 telescope of Mnt. Terskol observatory. The
optical afterglow (Hosokawa et al. GCN 31413; Siegel et al. GCN 31415;
Zhu et al. GCN 31416) is detected in stacked images. Preliminary
photometry of the afterglow is following.
Date UT start t-T0 Filter Exp. OT UL(3sigma) Telescope
(mid, days) (s)
2022-01-08 23:38:28 1.38573 R 42*60 20.26 0.14 21.4 AS-32
2022-01-09 01:58:01 1.48613 Clear 108*30 20.24 0.14 22.0 K-800
Photometry is based on the SDSS-DR12 nearby stars
RA DEC R(Lupton transformations)
11:19:03.5786 +34:06:35.141 17.75
11:19:08.2856 +34:14:46.786 16.73
11:18:58.9570 +34:17:07.910 17.46
We note a presence of a galaxy 8.7 arcsec West presented as
J111913.15+341014.4 in SDSS DR12 with r =19.623, i = 19.126 at
photometric redshift of z_ph = 0.34 +/- 0.066. Despite the galaxy is
unlikely to be the host galaxy of GRB 220107A, it might affect
photometry of the afterglow in a crude plate scale images.
GCN Circular 31422
Subject
GRB 220107A: SAO RAS optical observations
Date
2022-01-09T20:00:03Z (3 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO), A. Medvedev (SAO), A. Pozanenko (IKI)
and N. Pankov (HSE) on behalf of larger GRB follow-up team report:
We observed the field of GRB 220107A (The Fermi GBM team, GCN 31399;
Kunzweiler et al. GCN 31400; DeLaunay et al. GCN 31402; Suresh et al.,
GCN 31408) with the SAO RAS 1-m telescope Zeiss-1000 + CCD-photometer
in BVRc bands on January 9.
The OT (Hosokawa et al. GCN 31413; Siegel GCN 31415; Zhu et al.
GCN 31416; Pankov et al., GCN 31419) is detected in stacked images
in each filter. Preliminary photometry of the afterglow is as follows.
UT start -- UT end T_mid-T0, d Filter Exp., s mag +/- err
02:19:16 -- 03:00:13 1.4960 Rc 5 x 300 20.41 +/- 0.03
03:01:27 -- 03:18:33 1.5170 V 3 x 300 20.97 +/- 0.06
03:19:40 -- 03:36:26 1.5295 B 3 x 300 22.08 +/- 0.18
Photometry is based on nearby SDSS-DR12 stars
(magnitudes are converted with the Lupton 2005 transformations).
J2000.0 coordinates B V R
11:19:13.93 +34:08:38.8 16.244 15.691 15.363
11:19:13.74 +34:11:49.6 18.811 17.880 17.327
11:19:12.27 +34:11:18.1 18.959 18.506 18.241
GCN Circular 31423
Subject
GRB 220107A: 6m BTA spectroscopic redshift
Date
2022-01-09T20:07:17Z (3 years ago)
From
Alberto J. Castro-Tirado at IAA-CSIC <ajct@iaa.es>
A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev, A. Vinokurov and N.
Burenkov (SAO-RAS), Y.-D. Hu, M.D. Caballero-Garcia, R. Sanchez-Ramirez
and T-R. Sun (IAA-CSIC), on behalf of a larger collaboration, report:
Following the detection of GRB 220107A by Fermi/GRB (Fermi team GCNC
31399), Swift/BAT (DeLaunay et al. GCNC 31402) and AstroSat/CZTI (Suresh
et al. GCNC 31408), three spectra (600 s each, covering the 3700-8500 A
spectral range) of the optical afterglow (Hosokawa et al. GCNC 31413,
Siegel et al. GCNC 31415, Zhu et al. GCNC 31416, Pankov et al. GCNC
31419, Moskvitin et al. GCNC 31422) were obtained by the 6m BTA
(+SCORPIO-II) at the Special Astrophysical Observatory in Zelenchuk,
Russia, on Jan 8, 23:25 UT (mid-exposure time, 1.36 days postburst).
Several absorption lines (Fe II, Fe III, Mn II, Ni II and the Mg II
doublet) are clearly identified, all consistent with a redshift z =
1.246, which we propose to be the GRB redshift. We also confirm a
redshift z = 0.309 �� 0.001 for the unrelated foreground galaxy reported
by Pankov et al. (GCNC 31419), in agreement with the photometric redshift.
We acknowledge the excellent support of the BTA technical staff.
GCN Circular 31426
Subject
GRB 220107A: further SAO RAS optical observations
Date
2022-01-09T23:40:53Z (3 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO) and A. Medvedev (SAO),
on behalf of larger GRB follow-up team report:
We observed the field of GRB 220107A (The Fermi GBM team, GCN 31399;
Kunzweiler et al. GCN 31400; DeLaunay et al. GCN 31402; Suresh et al.,
GCN 31408) with the SAO RAS 1-m telescope Zeiss-1000 + CCD-photometer.
6 x 300 sec. images were obtained in Rc band on January 9,
22:27:09 -- 23:10:20 UT (T_mid - T0 = 2.3356 days).
The OT (Hosokawa et al. GCN 31413; Siegel GCN 31415; Zhu et al.
GCN 31416; Pankov et al., GCN 31419; Moskvitin et al., GCN 31422;
Castro-Tirado et al., GCN 31423) is clearly visible in the stacked
frame. Preliminary photometry of the afterglow is R = 21.01 +/- 0.04
(based on nearby SDSS-DR12 stars mentioned in GCN 31422).
GCN Circular 31429
Subject
Konus-Wind detection of GRB 220107A
Date
2022-01-10T19:41:10Z (3 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 220107A
(Fermi/GBM trigger #663259536: Fermi GBM Team, GCN 31399;
Kunzweiler et al., GCN 31400; Veres and Meegan, GCN 31406;
Swift/BAT-GUANO localization: DeLaunay et al., GCN 31402;
AstroSat CZTI detection: Suresh et al., GCN 31408)
triggered Konus-Wind at T0=53142.427 s UT (14:45:42.427).
The burst light curve shows a multipeaked structure
started at ~T0-7.6 s with a total duration of ~110.8 s.
The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220107_T53142/
As observed by Konus-Wind, the burst
had a fluence of 5.48(-0.30,+0.34)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+81.344 s,
of 8.18(-1.55,+1.54)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+105.984 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.02(-0.11,+0.12)
and Ep = 247(-24,+30) keV (chi2 = 53/61 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.4
(chi2 = 53/60 dof).
The spectrum near the maximum count rate
(measured from T0+73.984 to T0+89.600 s)
is best fit in the 20 keV - 2 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.86(-0.11,+0.12),
the high energy photon index beta = -2.91(-1.53,+0.32),
the peak energy Ep = 186(-15,+17) keV
(chi2 = 46/60 dof).
Assuming the redshift z=1.246 (Castro-Tirado et al., GCN 31423)
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the isotropic energy release E_iso to (2.3 �� 0.1)x10^53 erg,
the isotropic luminosity L_iso to (7.8 �� 1.5)x10^52 erg/s,
the rest-frame peak energy of the time-integrated spectrum Epi,z to (555 ��
67) keV,
and the rest-frame peak energy of the 'peak' spectrum Epp,z to (418 �� 38)
keV.
With these values, GRB 220107A is within 68% prediction bands for
for both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW
GRBs
with known redshifts (Tsvetkova et al., 2021, ApJ, 908, 83),
see http://www.ioffe.ru/LEA/GRBs/GRB220107_T53142/GRB220107A_rest_frame.pdf
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 31431
Subject
GRB 220107A: SAO RAS optical observations
Date
2022-01-11T05:08:48Z (3 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO), on behalf of larger GRB follow-up team report:
We observed the field of GRB 220107A (The Fermi GBM team, GCN 31399;
Kunzweiler et al. GCN 31400; DeLaunay et al. GCN 31402; Suresh et al.,
GCN 31408; Ridnaia et al., GCN 31429) with the SAO RAS 1-m telescope
Zeiss-1000 + CCD-photometer. Two series of images in Rc band
were obtained: the 1st under moderate weather conditions
and the 2nd with relatively clear sky.
The OT (Hosokawa et al. GCN 31413; Siegel GCN 31415; Zhu et al.
GCN 31416; Pankov et al., GCN 31419; Moskvitin et al., GCN 31422;
Castro-Tirado et al., GCN 31423, Moskvitin & Medvedev, GCN 31426)
is clearly visible in the stacked frames. Preliminary photometry
of the afterglow is as follows (based on nearby SDSS-DR12 stars
mentioned in GCNs 31422, 31426).
UT start -- UT end T_mid-T0, d Exp., s R_mag +/- err series
Jan. 10 Jan. 11
23:22:13 -- 02:06:39 3.41592 23 x 300 21.69 +/- 0.10 1st
Jan. 11 Jan. 11
02:49:39 -- 03:30:10 3.51694 8 x 300 22.03 +/- 0.09 2nd