Gamma-ray Burst 231222B

(All information courtesy of the instrument teams.)

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 22 Dec 23 13:01:41 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     724922767
GRB_RA:          253.460d {+16h 53m 50s} (J2000),
                 253.724d {+16h 54m 54s} (current),
                 252.910d {+16h 51m 38s} (1950)
GRB_DEC:         +18.760d {+18d 45' 36"} (J2000),
                 +18.722d {+18d 43' 20"} (current),
                 +18.841d {+18d 50' 26"} (1950)
GRB_ERROR:       1.28 [deg radius, statistical only]
GRB_DATE:        20300 TJD;   356 DOY;   23/12/22
GRB_TIME:        26762.19 SOD {07:26:02.19} UT
GRB_PHI:         288.93 [deg]
GRB_THETA:        17.79 [deg]
E_RANGE:         50.000 - 300.000 [keV]
LOC_ALGORITHM:   415 (Gnd S/W Version number)
SUN_POSTN:       270.44d {+18h 01m 47s}  -23.43d {-23d 26' 05"}
SUN_DIST:         45.21 [deg]   Sun_angle= 1.1 [hr] (West of Sun)
MOON_POSTN:       33.12d {+02h 12m 30s}  +14.60d {+14d 36' 13"}
MOON_DIST:       127.95 [deg]
MOON_ILLUM:      79 [%]
GAL_COORDS:       38.08, 34.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      249.07, 41.01 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231222310/quicklook/glg_lc_medres34_bn231222310.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231222310/quicklook/glg_locplot_all_bn231222310.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice has human-in-the-loop processing.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 22 Dec 23 18:29:53 UT
NOTICE_TYPE:     Fermi-LAT Offline Position
TRIGGER_NUM:     724922767
GRB_RA:          251.350d {+16h 45m 24s} (J2000),
                 251.612d {+16h 46m 27s} (current),
                 250.803d {+16h 43m 13s} (1950)
GRB_DEC:         +19.500d {+19d 30' 00"} (J2000),
                 +19.458d {+19d 27' 27"} (current),
                 +19.590d {+19d 35' 25"} (1950)
GRB_ERROR:       17.99 [arcmin radius, 90% containment, statistical only]
GRB_DATE:        20300 TJD;   356 DOY;   23/12/22
GRB_TIME:        26762.19 SOD {07:26:02.19} UT
TRIGGER_ID:      0x0
MISC:            0x40000000
SUN_POSTN:       270.70d {+18h 02m 47s}  -23.43d {-23d 26' 01"}
SUN_DIST:         46.76 [deg]   Sun_angle= 1.3 [hr] (West of Sun)
MOON_POSTN:       36.06d {+02h 24m 14s}  +15.87d {+15d 52' 23"}
MOON_DIST:       130.30 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:       38.08, 36.20 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      246.30, 41.42 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi LAT Offline position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        It is the result of human-in-the-loop processing.  
COMMENTS:        This is a human generated position of a LAT ground detection.
COMMENTS:        This source corresponds to GBM trigger 231222310/724922767.

GCN Circular #35416
N. Di Lalla (Stanford University), F. Longo (University and INFN, Trieste), A. Holzmann (DF, University of Buenos Aires, Argentina) report on behalf of the Fermi-LAT Collaboration:
On December 22, 2023 Fermi-LAT detected high-energy emission from GRB 231222B, which was also detected by Fermi-GBM (trigger 724922767 / 231222310).
The best LAT on-ground location is found to be
RA, Dec = 251.35, 19.55 (degrees, J2000)
with an error radius of 0.3 deg (90% containment, statistical error only). This was 19 deg from the LAT boresight at the time of the GBM trigger:
T0 = 07:26:02.19 UT.
The data from the Fermi-LAT show a significant increase in the event rate after the GBM trigger that is spatially correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval**0-600 s after the GBM trigger is (1.9 +/- 0.7) E-6**ph/cm2/s.
The estimated photon index above 100 MeV is -1.7 +/- 0.3. The highest-energy photon is a 3.6 GeV event which is observed 362 seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is Makoto Arimoto (arimoto@se.kanazawa-u.ac.jp )
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #35417
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (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. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich (Blagoveschensk Educational State University)
MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the LAT GRB231222.31 (trigger No 724922767,16h 45m 24.00s , +19d 30m 00.0s, R=0.299833) errorbox 9379 sec after notice time and 49215 sec after trigger time at 2023-12-22 21:06:17 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 81 deg. The sun altitude is -36.5 deg.
The galactic latitude b = 36 deg., longitude l = 38 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2340436
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   49278 | 2023-12-22 21:06:17 |        MASTER-Tunka | (16h 44m 15.30s , +19d 23m 06.7s) |   C |   125 | 14.8 |        
   51473 | 2023-12-22 21:42:45 |        MASTER-Tunka | (16h 44m 16.33s , +19d 24m 26.0s) |   C |   140 | 15.2 |        
   51624 | 2023-12-22 21:45:16 |        MASTER-Tunka | (16h 44m 22.24s , +19d 23m 36.0s) |   C |   140 | 18.1 |        
   51733 | 2023-12-22 21:47:50 |        MASTER-Tunka | (16h 44m 17.59s , +19d 22m 40.5s) |   C |    50 | 17.4 |        
   51781 | 2023-12-22 21:47:50 |        MASTER-Tunka | (16h 44m 17.59s , +19d 22m 40.4s) |   C |   145 | 18.1 |  Coadd 
   51794 | 2023-12-22 21:48:50 |        MASTER-Tunka | (16h 44m 22.74s , +19d 22m 52.8s) |   C |    50 | 17.5 |        
   51851 | 2023-12-22 21:49:50 |        MASTER-Tunka | (16h 44m 20.66s , +19d 24m 35.0s) |   C |    45 | 17.5 |        
   51908 | 2023-12-22 21:50:47 |        MASTER-Tunka | (16h 44m 20.65s , +19d 23m 01.1s) |   C |    45 | 17.5 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited. Th View this GCN Circular online at https://gcn.nasa.gov/circulars/35417.
GCN Circular #35418
P. Veres (UAH), V. Sharma (NASA-GSFC/UMBC) and R. Hamburg (CNRS/IN2P3) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 07:26:02.19 UT on 22 December 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 231222B (trigger 724922767/231222310). The GRB was also detected by Fermi LAT (Di Lalla et al, GCN 35416).
The angle from the Fermi LAT boresight is 19 degrees.
The GBM light curve consists of two widely separated pulses with a duration (T90) of about 121 s (50-300 keV). The time-averaged spectrum from T0-5.1 to T0+126.0 s is best fit by a simple power law function with index -1.55 +/- 0.04.
The event fluence (10-1000 keV) in this time interval is (5.7 +/- 0.6)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.7 s in the 10-1000 keV band is 6.0 +/- 0.3 ph/s/cm^2.
A power law function with an exponential high-energy cutoff fits the spectrum equally well. The power law index is -1.09 +/- 0.16 and the cutoff energy, parameterized as Epeak, is 257 +/- 67 keV.
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 #35421
M. Ferro (INAF-OAB), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 231222B in a series of observations tiled on the sky. We point out that the burst was improperly named GRB 231222A in GCN Circ 35415, where the tiling was announced. The total exposure time is 4.1 ks, distributed over 4 tiles; the maximum exposure at a single sky location was 2.3 ks. The data were collected between T0+43.2 ks and T0+54.8 ks, and are entirely in Photon Counting (PC) mode.
Three uncatalogued X-ray sources are detected, of which one ("Source 1") is believed to be the afterglow. Using 1211 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 = 251.24744, +19.62084 which is equivalent to:
```
RA (J2000): 16h 44m 59.39s
Dec(J2000): +19d 37' 15.0"
```
with an uncertainty of 3.3 arcsec (radius, 90% confidence). This position is 9.3 arcmin from the Fermi/LAT position. The source has a mean count rate of 6.0e-02 ct/sec; we cannot determine at the present time whether it is fading.
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.65 (+0.49, -0.29). The best-fitting absorption column is consistent with the Galactic value of 7.1 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 3.4 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1.
```
A summary of the PC-mode spectrum is thus:
Total column:	     7 (+/-14) x 10^20 cm^-2
Galactic foreground: 7.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.65 (+0.49, -0.29)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021639. The results of the full analysis of the tiled XRT observations are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00118.
This circular is an official product of the Swift-XRT team.
GCN Circular #35425
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner= (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (= Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Sza= kszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Po= valac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r= .o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovs= ky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.)= , Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. B= ozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eot= vos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hi= sadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Ki= ss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.= ), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima = U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo)= , T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 231222B (Fermi/GBM detection: GCN 35418; Fermi/LAT de= tection: GCN 35416; INTEGRAL/SPI-ACS peak detection at 2023-12-22 ~07:26:03= UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40= ; arXiv:2302.10048).
The detection was confirmed at the peak time 2023-12-22 07:26:04 UTC. The T= 90 duration measured by GRBAlpha is 5 s and the overall significance during= T90 reaches 6.2 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.ko= nkoly.hu/static/share/GRB231222B_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/he= a/GRBAlpha/=20 GRBAlpha, launched on 2021 March 22, is a demonstration mission for a futur= e CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GR= BAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM ar= ray, covering the energy range from ~50 keV to ~1000 keV. To increase the d= uty cycle and the downlink rate, the upgrade of the on-board data acquisiti= on software stack is in progress. The ground segment is also supported by t= he radio amateur community and it takes advantage of the SatNOGS network fo= r increased data downlink volume.=20

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Jochen Greiner, last update: 24-Dec-2023 [Disclaimer]