GRB 240123A
GCN Circular 35602
Subject
GRB 240123A: Swift detection of a burst with a possible optical counterpart
Date
2024-01-23T11:34:56Z (a year ago)
From
Antonino D'Ai' at IASF-PA <antonino.dai@inaf.it>
Via
email
A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU),
A. Y. Lien (U Tampa), A. Melandri (INAF-OAR),
K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 11:05:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240123A (trigger=1210276). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 199.319, +60.632 which is
RA(J2000) = 13h 17m 16s
Dec(J2000) = +60d 37' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 25 sec. The peak count rate
was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 11:08:08.6 UT, 141.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 199.34797,
60.61894 which is equivalent to:
RA(J2000) = 13h 17m 23.51s
Dec(J2000) = +60d 37' 08.2"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 69 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.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.45 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.7
(+2.69/-2.33) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 7.30e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 151 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 13:17:23.25 = 199.3468
DEC(J2000) = +60:37:04.4 = 60.6179
with a 90%-confidence error radius of about 0.2 arc sec. This position is 4.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.9 with a 1-sigma error of about 0.2. No correction has been made for the
expected extinction.
Burst Advocate for this burst is A. D'Ai (antonino.dai AT inaf.it).
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 35605
Subject
GRB 240123A: Mondy optical afterglow observations
Date
2024-01-23T15:52:15Z (a year ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 231117A (D'Ai et al., GCN 35602) with AZT-33IK telescope of Mondy observatory in R-filter starting on 2024-01-23 (UT) 14:00:48. We clearly detect a new fading object at coordinates (J2000) 13 17 23.87 +60 37 05.3 with uncertainties of 0.2 arcsec which is slightly differ from coordinates reported by UVOT (D'Ai et al., GCN 35602). The object is absent in SDSS catalogue. Preliminary photometry is following
Date UT start t-T0 Exp. Filter OT Err.
(mid, days) (s)
2024-01-23 14:00:48 0.126415 7x120 R 19.07 0.10 20.9
2024-01-23 14:20:48 0.144479 13x120 R 19.25 0.10 21.3
2024-01-23 14:46:49 0.163934 15x120 R 19.37 0.11 21.3
The photometry is based on nearby USNO-B1.0 R2 stars.
GCN Circular 35609
Subject
GRB 240123A: Mondy continued optical observations + correction of the GRB name in GCN 35605
Date
2024-01-23T18:06:11Z (a year ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continued to observe the afterglow of GRB 240123A (D'Ai et al., GCN 35602) with AZT-33IK telescope of Mondy observatory in R-filter originally started on 2024-01-23 (UT) 14:00:48 (Pankov et al., GCN 35605). We confirm the afterglow decay, which detected previously (D'Ai et al., GCN 35602; Pankov et al., GCN 35605).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Exp. Filter OT Err. UL(3sigma)
(mid, days) (s)
2024-01-23 16:03:39 0.227009 29x120 R 19.87 0.10 21.9
The photometry is based on nearby USNO-B1.0 R2 stars.
We are also reporting the incorrect name of the GRB in GCN Circular No. 35605. The correct name of the GRB in GCN Circular #3560 should be GRB 240123A.
GCN Circular 35610
Subject
Fermi GBM Sub-Threshold Detection of GRB 240123A
Date
2024-01-23T19:36:21Z (a year ago)
From
Lorenzo Scotton at UAH <lscottongcn@outlook.com>
Via
Web form
L. Scotton (UAH) reports on behalf of the Fermi-GBM Team:
Swift-BAT detected GRB 240123A at 11:05:46 UT (D'Ai et al. 2024, GCN 35602). There was no
Fermi-GBM onboard trigger around the event.
An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified no counterparts.
The GBM targeted search [1], the most sensitive, coherent search for
GRB-like signals identified a transient most significantly on the 8.192 s
timescale, with a false alarm rate of 3.9e-05 Hz and a location consistent with
the Swift-BAT event, using the standard search protocol with a S/N of 13.
The GBM targeted search event was found with the highest
significance with a "normal" spectrum (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB.
[1] Goldstein et al. 2019 arXiv:1903.12597
GCN Circular 35612
Subject
GRB 240123A: Swift-XRT refined Analysis
Date
2024-01-23T22:11:25Z (a year ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), J. D. Gropp
(PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), V.
D'Elia (SSDC & INAF-OAR) and P.A. Evans report on behalf of the
Swift-XRT team:
We have analysed 6.5 ks of XRT data for GRB 240123A, from 131 s to 23.7
ks after the BAT trigger. The data comprise 164 s in Windowed Timing
(WT) mode (the first 8 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. The refined XRT position is RA,
Dec = 199.3473, +60.6184 which is equivalent to:
RA (J2000): 13 17 23.34
Dec(J2000): +60 37 06.1
with an uncertainty of 3.5 arcsec (radius, 90% confidence).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=7.2 (+0.8, -2.8). At T+145 s the decay
flattens to an alpha of 0.3 (+1.0, -1.8). The light curve breaks again
at T+183 s to a decay with alpha=2.91 (+0.20, -0.19), before a final
break at T+635 s s after which the decay index is 0.58 (+/-0.08).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.35 (+0.09, -0.07). The
best-fitting absorption column is consistent with the Galactic value
of 1.4 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 2.01 (+0.17, -0.13) and a best-fitting absorption
column of 2.3 (+3.3, -0.9) x 10^20 cm^-2. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 3.2 x 10^-11 (3.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.3 (+3.3, -0.9) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 2.01 (+0.17, -0.13)
If the light curve continues to decay with a power-law decay index of
0.58, the count rate at T+24 hours will be 0.028 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.0 x
10^-13 (9.6 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/01210276.
This circular is an official product of the Swift-XRT team.
GCN Circular 35616
Subject
GRB 240123A: Enhanced Swift-XRT position
Date
2024-01-24T03:40:02Z (a year ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 596 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 240123A, 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 = 199.34861, +60.61849 which is equivalent
to:
RA (J2000): 13h 17m 23.67s
Dec (J2000): +60d 37' 06.6"
with an uncertainty of 2.1 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 35618
Subject
GRB 240123A : MITSuME Akeno optical afterglow candidate detection
Date
2024-01-24T08:57:45Z (a year ago)
From
Mahito Sasada at Tokyo Institute of Technology <sasada@hp.phys.titech.ac.jp>
Via
Web form
M. Sasada, I. Takahashi, N. Higuchi, M. Niwano, S. Sato, S. Hayatsu, H. Takei, H. Seki, Y. Yatsu and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 240123A (D'Ai et al. GCN 35602) 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 started at 2024-01-23 15:09:01 UT (4.05 hours after the Swift/BAT trigger). We stacked the images in good conditions. An optical candidate of the afterglow can be found at the location of (RA, Dec) = (199.3495, 60.6181) near the Swift/XRT error position (Capalbi et al. GCN 35612). Here we report magnitudes by the aperture photometry at the position.
T0+[hours] | MID-UT | T-EXP[sec] | magnitudes of aperture photometry
----------------------------------------------------------------------------------------------------------------
5.0 | 2024-01-23 16:05:41 | 5880 | g’=19.83+/-0.17, Rc=19.35+/-0.11, Ic=19.24+/-0.13
----------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time
The position of the optical candidate is consistent with Pankov et al., GCN 35605.
We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g'-, Rc- and Ic-band magnitudes following 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 35619
Subject
GRB 240123A: SAO RAS optical observations
Date
2024-01-24T11:10:25Z (a year ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
Via
legacy email
A. S. Moskvitin, O. A. Maslennikova, O. I. Spiridonova (SAO RAS)
report on behalf of the GRB follow-up team.
We observed the field of GRB 240123A (D'Ai et al., GCN #35602;
Scotton, GCN #35610) with the 1-m telescope of SAO RAS equipped
with the CCD photometer. We obtained 12 x 300 sec. images in Rc
band on Jan 24, 02:15:54 -- 03:42:02 UT (t_mid - T0 = 0.66194 days).
The OT (D'Ai et al., GCN #35602; Pankov et al., GCNs #35605, #35609;
Sasada et al., GCN #35618) is clearly detected in our stacked frame
with the brightness of R = 21.12 +/- 0.09.
The photometry is based on R2 magnitudes of nearby USNO-B1 stars.
GCN Circular 35620
Subject
GRB 240123A: Mondy continued optical observations and the PL decay index
Date
2024-01-24T15:44:05Z (a year ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We continued to observe the afterglow of GRB 240123A (D'Ai et al., GCN 35602; Pankov et al., GCN 35605, GCN 35609; Sasada et al., GCN 35618; Moskvitin at al., GCN 35619) with AZT-33IK telescope of Mondy observatory in R-filter.
Using previously reported photometry (Pankov et al., GCN 35605, GCN 35609; Moskvitin at al., GCN 35619) and photometry obtained on t-T0 0.400722 we approximate the light curve with a PL model with the index of PL alpha = -1.1, see Figure at
http://grb.rssi.ru/GRB240123A/GRB240123A_LC_approximation.jpg
GCN Circular 35622
Subject
GRB 240123A: Swift-BAT refined analysis
Date
2024-01-24T18:12:15Z (a year ago)
From
Amy <yarleen@gmail.com>
Via
email
T. Parsotan (GSFC), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), M. J. Moss (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+820 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 240123A (trigger #1210276)
(D'Ai, et al., GCN Circ. 35602). The BAT ground-calculated position is
RA, Dec = 199.287, 60.607 deg which is
RA(J2000) = 13h 17m 08.9s
Dec(J2000) = +60d 36' 25.6"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 31%.
The mask-weighted light curve shows some weak emission with complex
structures
that starts at ~T0 and ends at ~T+140 s. The main peak occurs at ~T+5 s.
T90 (15-350 keV) is 115.30 +- 54.93 sec (estimated error including
systematics).
The time-averaged spectrum from T-0.69 to T+140.46 sec is best fit by a
simple
power-law model. The power law index of the time-averaged spectrum is
1.69 +- 0.23. The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+5.49 sec in the 15-150 keV band
is 1.1 +- 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/1210276/BA/
GCN Circular 35624
Subject
GRB 240123A: further SAO RAS optical observations
Date
2024-01-25T05:12:41Z (a year ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
Via
legacy email
A. S. Moskvitin, O. A. Maslennikova, O. I. Spiridonova (SAO RAS)
report on behalf of the GRB follow-up team.
We observed the field of GRB 240123A (D'Ai et al., GCN #35602;
Scotton, GCN #35610) with the 1-m telescope of SAO RAS equipped
with the CCD photometer. We obtained 16 x 300 sec. images in Rc
band on Jan 25, 01:55:52 -- 03:30:49 UT (t_mid - T0 = 1.6511 days).
The OT (D'Ai et al., GCN #35602; Pankov et al., GCNs #35605, #35609
#35620; Sasada et al., GCN #35618) is detected in our stacked frame
with the brightness of R = 22.0 +/- 0.2.
The photometry is based on R2 magnitudes of nearby USNO-B1.0 stars.
GCN Circular 35628
Subject
GRB 240123A: GRBAlpha detection
Date
2024-01-25T14:21:21Z (a year ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
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. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (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. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (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 240123A (Swift/BAT detection: GCN 35602; Fermi/GBM detection: GCN 35610; INTEGRAL/SPI-ACS peak detection at 2024-01-23 ~11:05:47) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
The subthreshold detection was confirmed at the peak time 2024-01-23 11:05:49 UTC. The T90 duration measured by GRBAlpha is 8 s and the overall significance during T90 reaches 3.5 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240123A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN Circular 35631
Subject
GRB 240123A: Glowbug gamma-ray detection
Date
2024-01-25T18:11:33Z (a year ago)
From
C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>
Via
Web form
C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240123A, which was also detected by Swift/BAT (GCN 35602, 35622), Fermi/GBM (GCN 35610), and GRBAlpha (GCN 35628).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-01-23 11:05:48.840 with a duration of 6.1 s and a total significance of about 12.2 sigma. The light curve comprises a single peak.
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=-0.4 and a cutoff energy ("Epeak") of 719 keV. The modeled 10-10000 keV fluence is 1.3e-06 erg/cm^2.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
Distribution Statement A: Approved for public release. Distribution is unlimited.