- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:48:39 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 45
TRIGGER_NUM: 727235294
GRB_RA: 8.833d {+00h 35m 20s} (J2000),
9.160d {+00h 36m 38s} (current),
8.157d {+00h 32m 38s} (1950)
GRB_DEC: +40.833d {+40d 49' 60"} (J2000),
+40.966d {+40d 57' 56"} (current),
+40.558d {+40d 33' 29"} (1950)
GRB_ERROR: 21.93 [deg radius, statistical plus systematic]
GRB_INTEN: 97 [cnts/sec]
DATA_SIGNIF: 4.70 [sigma]
INTEG_TIME: 1.024 [sec]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 93.00 [deg]
GRB_THETA: 55.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO: 0.04
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 92% GRB
2nd_MOST_LIKELY: 6% Cyg X-1
DETECTORS: 0,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN: 299.51d {+19h 58m 02s} -20.67d {-20d 40' 05"}
SUN_DIST: 89.18 [deg] Sun_angle= -4.6 [hr] (East of Sun)
MOON_POSTN: 24.19d {+01h 36m 45s} +10.60d {+10d 35' 49"}
MOON_DIST: 33.13 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 119.65,-21.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 26.13, 33.62 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 126.22,24.85 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:49:00 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 67
TRIGGER_NUM: 727235294
GRB_RA: 17.200d {+01h 08m 48s} (J2000),
17.533d {+01h 10m 08s} (current),
16.509d {+01h 06m 02s} (1950)
GRB_DEC: +32.017d {+32d 01' 00"} (J2000),
+32.144d {+32d 08' 40"} (current),
+31.750d {+31d 45' 01"} (1950)
GRB_ERROR: 6.88 [deg radius, statistical plus systematic]
GRB_INTEN: 328 [cnts/sec]
DATA_SIGNIF: 14.30 [sigma]
INTEG_TIME: 1.024 [sec]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 94.00 [deg]
GRB_THETA: 65.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO: 0.79
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 96% GRB
2nd_MOST_LIKELY: 2% Generic Transient
DETECTORS: 0,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN: 299.51d {+19h 58m 02s} -20.67d {-20d 40' 05"}
SUN_DIST: 91.34 [deg] Sun_angle= -5.2 [hr] (East of Sun)
MOON_POSTN: 24.19d {+01h 36m 46s} +10.60d {+10d 35' 54"}
MOON_DIST: 22.41 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 127.21,-30.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 28.56, 22.75 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 126.22,24.85 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:48:57 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 57
TRIGGER_NUM: 727235294
GRB_RA: 32.110d {+02h 08m 26s} (J2000),
32.444d {+02h 09m 47s} (current),
31.417d {+02h 05m 40s} (1950)
GRB_DEC: +19.830d {+19d 49' 48"} (J2000),
+19.943d {+19d 56' 35"} (current),
+19.593d {+19d 35' 36"} (1950)
GRB_ERROR: 12.04 [deg radius, statistical only]
DATA_SIGNIF: 8.20 [sigma]
DATA_INTERVAL: 4.096 [sec]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 100.00 [deg]
GRB_THETA: 83.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 299.51d {+19h 58m 02s} -20.67d {-20d 40' 05"}
SUN_DIST: 99.52 [deg] Sun_angle= -6.2 [hr] (East of Sun)
MOON_POSTN: 24.19d {+01h 36m 45s} +10.60d {+10d 35' 53"}
MOON_DIST: 12.27 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 146.62,-39.47 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 36.69, 6.45 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_727235294.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
COMMENTS: The LC_URL file will not be created/available until ~15 min after the trigger.
COMMENTS: The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:49:26 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 91
TRIGGER_NUM: 727235294
GRB_RA: 13.867d {+00h 55m 28s} (J2000),
14.197d {+00h 56m 47s} (current),
13.182d {+00h 52m 44s} (1950)
GRB_DEC: +34.500d {+34d 30' 00"} (J2000),
+34.630d {+34d 37' 48"} (current),
+34.229d {+34d 13' 46"} (1950)
GRB_ERROR: 5.17 [deg radius, statistical plus systematic]
GRB_INTEN: 489 [cnts/sec]
DATA_SIGNIF: 44.00 [sigma]
INTEG_TIME: 4.096 [sec]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 93.00 [deg]
GRB_THETA: 60.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO: 0.58
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 95% GRB
2nd_MOST_LIKELY: 4% Generic Transient
DETECTORS: 0,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN: 299.51d {+19h 58m 03s} -20.67d {-20d 40' 05"}
SUN_DIST: 89.84 [deg] Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN: 24.19d {+01h 36m 46s} +10.60d {+10d 36' 01"}
MOON_DIST: 25.70 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 123.88,-28.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 26.93, 26.17 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 126.22,24.85 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:49:32 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 95
TRIGGER_NUM: 727235294
GRB_RA: 14.000d {+00h 56m 00s} (J2000),
14.330d {+00h 57m 19s} (current),
13.315d {+00h 53m 16s} (1950)
GRB_DEC: +34.283d {+34d 16' 60"} (J2000),
+34.413d {+34d 24' 47"} (current),
+34.013d {+34d 00' 46"} (1950)
GRB_ERROR: 4.45 [deg radius, statistical plus systematic]
GRB_INTEN: 841 [cnts/sec]
DATA_SIGNIF: 74.90 [sigma]
INTEG_TIME: 4.096 [sec]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 93.00 [deg]
GRB_THETA: 60.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO: 0.63
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 96% GRB
2nd_MOST_LIKELY: 3% Generic Transient
DETECTORS: 0,0,0, 0,0,0, 0,0,0, 1,1,0, 0,0,
SUN_POSTN: 299.51d {+19h 58m 03s} -20.67d {-20d 40' 05"}
SUN_DIST: 89.85 [deg] Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN: 24.19d {+01h 36m 47s} +10.60d {+10d 36' 02"}
MOON_DIST: 25.46 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 124.01,-28.58 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 26.94, 25.93 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 126.22,24.85 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 01:57:29 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 727235294
GRB_RA: 14.100d {+00h 56m 24s} (J2000),
14.428d {+00h 57m 43s} (current),
13.420d {+00h 53m 41s} (1950)
GRB_DEC: +30.880d {+30d 52' 48"} (J2000),
+31.010d {+31d 00' 35"} (current),
+30.610d {+30d 36' 35"} (1950)
GRB_ERROR: 1.00 [deg radius, statistical only]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.44 SOD {01:48:09.44} UT
GRB_PHI: 91.00 [deg]
GRB_THETA: 63.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 299.52d {+19h 58m 04s} -20.67d {-20d 40' 01"}
SUN_DIST: 88.46 [deg] Sun_angle= -5.0 [hr] (East of Sun)
MOON_POSTN: 24.26d {+01h 37m 03s} +10.63d {+10d 38' 05"}
MOON_DIST: 22.32 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 124.19,-31.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 25.44, 22.81 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_locplot_all_bn240118075.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 was generated completely by automated pipeline processing.
COMMENTS: This is likely a Long GRB.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(16.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=10477).
- GCN Circular #35558
The Fermi GBM team reports the detection of a likely LONG GRB
At 01:48:09 UT on 18 Jan 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240118A (trigger 727235294.440514 / 240118075).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 14.1, Dec = 30.9 (J2000 degrees, equivalent to J2000 00h 56m, 30d 53'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 63.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_skymap_all_bn240118075.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_healpix_all_bn240118075.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240118075/quicklook/glg_lc_medres34_bn240118075.gif
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 18 Jan 24 07:43:34 UT
NOTICE_TYPE: Fermi-LAT Offline Position
TRIGGER_NUM: 727235294
GRB_RA: 18.575d {+01h 14m 18s} (J2000),
18.908d {+01h 15m 38s} (current),
17.885d {+01h 11m 32s} (1950)
GRB_DEC: +29.789d {+29d 47' 20"} (J2000),
+29.916d {+29d 54' 57"} (current),
+29.525d {+29d 31' 28"} (1950)
GRB_ERROR: 3.00 [arcmin radius, 90% containment, statistical only]
GRB_DATE: 20327 TJD; 18 DOY; 24/01/18
GRB_TIME: 6489.43 SOD {01:48:09.43} UT
TRIGGER_ID: 0x20000000
MISC: 0x40000000
SUN_POSTN: 299.77d {+19h 59m 05s} -20.62d {-20d 37' 08"}
SUN_DIST: 91.30 [deg] Sun_angle= -5.3 [hr] (East of Sun)
MOON_POSTN: 27.31d {+01h 49m 14s} +12.10d {+12d 05' 60"}
MOON_DIST: 19.45 [deg]
MOON_ILLUM: 52 [%]
GAL_COORDS: 128.84,-32.82 [deg] galactic lon,lat of the burst (or
+transient)
ECL_COORDS: 28.75, 20.23 [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.
- GCN Circular #35560
E. Bissaldi (Politecnico and INFN Bari), F. Longo (University and INFN Trieste)
and Makoto Arimoto (Kanazawa University) report on behalf of the Fermi-LAT Collaboration:
At 01:48:09.44 on January, 18, 2024 Fermi-LAT detected high-energy emission
from GRB 240118A, which was also detected by Fermi-GBM (trigger 727235294 / 240118075,
GCN #35558).
The best LAT on-ground location is found to be
RA, Dec = 18.57, 29.79 (J2000)
with an error radius of 0.05 deg (90 % containment, statistical error only).
This was 69 deg from the LAT boresight at the time of the trigger.
The data from the Fermi-LAT show a significant increase in the event rate
that is spatially and temporally correlated with the trigger with high significance.
The photon flux above 100 MeV in the time interval 0-2000 s
after the GBM trigger time is (7.3 +/- 1.0)E-6 ph/cm2/s.
The estimated photon index above 100 MeV is -1.9 +/- 0.1.
The highest-energy photon is a 41 GeV event, which is observed
732 seconds after the GBM trigger.
A Swift ToO has been requested for this burst.
The Fermi-LAT point of contact for this burst is
Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).
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 #35563
R. Hamburg (CNRS/IN2P3), S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 01:48:09.44 UT on 18 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240118A (trigger 727235294/240118075),
which was also detected by Fermi-LAT (Bissaldi et al. 2024, GCN 35560).
The Fermi GBM on-ground location (GCN 35558) is consistent with the Fermi-LAT position.
The angle from the Fermi LAT boresight is 64 degrees.
The GBM light curve consists of multiple bright pulses with a duration (T90)
of about 54 s (50-300 keV). The time-averaged spectrum
from T0+0 s to T0+150 s is best fit by
a Band function with Epeak = 374 +/- 3 keV,
alpha = -0.71 +/- 0.004, and beta = -2.35 +/- 0.02.
The event fluence (10-1000 keV) in this time interval is
(5.81 +/- 0.01)E-04 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+72.5 s in the 10-1000 keV band is 94.6 +/- 0.5 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 #35564
B. Grefenstette on behalf of the NuSTAR Search for INteresting Gamma-ray
Signals (SINGS) working group:
The NuSTAR SINGS working group reports the detection of prompt emission of
the GRB 240118A in the NuSTAR CsI anti-coincidence shields. Thus GRB was id=
entified through a blind search using the CsI shield rates with a trigger t=
ime (2024-01-18 01:48:46). This is consistent with the time of the delayed
large peak seen in the GBM lightcurve from Fermi GBM (Fermi Team GCN 35558,
Hamburg GCN 35563) which arrives ~40-sec after the initial GBM trigger at
01:48:09. Data from the CdZnTe detectors have not yet been downloaded from
the spacecraft.
The burst shows at least three broad peaks in the CsI shields from both
NuSTAR FPMs, peaking at 3000-5000 counts per second (the background in the shields was roughly 1000 cps).
The automated light curve report for this GRB and discovery report can be found here:
https://nustarsoc.caltech.edu/NuSTAR_Public/grbs/reports/2024/240118A/
=E2=80=A6where further offline analysis will be performed once more data ar=
e downloaded from NuSTAR.
- GCN Circular #35567
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long, very bright GRB 240118A
(Fermi GBM observation: Hamburg et al., GCN 35563;
Fermi LAT detection: Bissaldi et al., GCN 35560;
NuSTAR detection: Grefenstette, GCN 35564)
triggered Konus-Wind (KW) at T0=3D6508.107 s UT (01:48:28.107).
The burst light curve shows a multi-peaked structure,
which starts at ~T0-2.4 s, peaks at ~T0+37.5 s,
and has a total duration of ~90 s.
The emission is seen up to ~15 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240118_T06508/
As observed by Konus-Wind, the burst had
a fluence of (8.24 =C2=B1 0.38)x10^-4 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 37.568 s,
of (6.65 =C2=B1 0.63)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy =
range).
The time-integrated spectrum (measured from T0 to T0+90.880 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha =3D -0.69 (-0.03,+0.03),
the high energy photon index beta =3D -2.37 (-0.05,+0.05),
the peak energy Ep =3D 402 (-12,+13) keV,
chi2 =3D 167/97 dof.
The spectrum near the peak count rate (measured from T0+36.352 s to T0+38.1=
44 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha =3D -0.61 (-0.06,+0.07),
the high energy photon index beta =3D -2.62 (-0.21,+0.15),
the peak energy Ep =3D 634 (-51,+55) keV,
chi2 =3D 74/66 dof.
All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.
- GCN Circular #35568
James DeLaunay (PSU), Samuele Ronchini (PSU), Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 240118A onboard (T0: 2024-01-18T01:48:09.44 UTC, Fermi trig 727235294, Konus-Wind GCN 35567, NuSTAR GCN 35564)
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 BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0+32 s, T0+72 s] (centered around the peak count rate), detects the burst with a sqrt(TS) of 125.5 in a 16.384 s analysis time bin, starting at T0 + 43.808.
NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -930.9.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
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 #35570
B. Grefenstette on behalf of the NuSTAR Search for INteresting Gamma-ray Signals (SINGS) working group:
The NuSTAR SINGS working group has performed additional offline analysis of the GRB 240118A detected by Fermi (Hamburg, GCN 35563), Swift BAT (DeLaunay, GCN 35568), and Konus-Wind (Frederiks, GCN 35567). Using the localization from the Fermi LAT (Bissaldi, GCN 35560) we estimate that the GRB was only ~12-degrees from the telescope boresight at 2024-01-18T01:48:09.
The CsI shields do not clearly detect the precursor event that triggered the GBM at 2024-01-18T01:48:09. However, there are multiple strong peaks ~40-sec later. We have updated the automated GRB report to include the recently downloaded X-ray data here:
https://nustarsoc.caltech.edu/NuSTAR_Public/grbs/reports/2024/240118A/
This includes enhanced light curves showing 1-Hz CsI anticoincidence shield data as well as the CdZnTe X-ray data binned at 2-s intervals. The shield data clearly resolves the GRB into at least three main peaks with significant substructure. All three peaks are also seen in the X-ray detectors, with excess counts that extend up to at least 200 keV.
However, the response files of the detectors is complicated due to the intervening material so detailed spectroscopic analysis of the individual bursts cannot be performed at this time.
- GCN Circular #35572
N. Pankov (HSE, IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), S. Belkin (IKI) report on behalf of IKI GRB FuN:
We observed the field of Fermi LAt localization of GRB 240118A (Bissaldi, GCN 35560) and detected also Fermi GBM (Fermi GBM team, GCN 35558; Hamburg, GCN 35563), NuSTAR (Grefenstette, GCN 35564), Swift BAT (DeLaunay, GCN 35568), and Konus-Wind (Frederiks, GCN 35567) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on 2024-01-18 (UT) 16:47:55. No optical candidate is detected in the LAT localization area (Bissaldi, GCN 35560). Preliminary photometry of the filed is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2024-01-18 16:47:55 0.625069 R 40*60 n/d n/d 17.4
The photometry is based on nearby USNO-B1.0 stars.
- GCN Circular #35573
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/LAT GRB 240118A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021644
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 Fermi/LAT 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 #35580
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 bright long-duration GRB 240118A (Fermi/GBM detection: GCN 35558; Fermi=
/LAT detection: GCN 35560; NuSTAR detection: GCN 35564; Konus/Wind detectio=
n: GCN 35567; Swift/BAT detection: GCN 35522; INTEGRAL/SPI-ACS detection: t=
rigger no. 10477) 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 2024-01-18 01:49:22 UTC. The T=
90 duration measured by GRBAlpha is 58 s and the overall significance durin=
g T90 reaches 174 sigma.
The light curve shows a multiple-peaked structure which is consistent with =
light curves observed by other missions. However, GRBAlpha was passing thro=
ugh the van Allen radiation belt during the entire burst duration and there=
fore the measured count rate is subject to a higher variable background whi=
ch cannot be distinguished from the burst itself.
The light curve obtained by GRBAlpha is available here: https://grbalpha.ko=
nkoly.hu/static/share/GRB240118A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
>BR>
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
- GCN Circular #35587
A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), A. Tohuvavohu (U. Toronto),
D.N. Burrows (PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester) 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 240118A, collecting 4.7 ks of Photon
Counting (PC) mode data between T0+96.2 ks and T0+109.0 ks.
Two uncatalogued X-ray sources are detected consistent with being
within 296 arcsec of the Fermi/LAT position, of which one ("Source 3")
is believed to be the afterglow. Using 4697 s of PC mode data and 3
UVOT images, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 18.53587, +29.79798 which is equivalent to:
RA (J2000): 01h 14m 08.61s
Dec(J2000): +29d 47' 52.7"
with an uncertainty of 2.7 arcsec (radius, 90% confidence). This
position is 2.1 arcmin from the Fermi/LAT position. The light curve is
consistent with a constant source of mean count rate 3.6e-02 ct/sec. A
power-law fit gives an index of 1.9 (+1.0, -2.8).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+/-0.6). The
best-fitting absorption column is 1.1 (+0.8, -0.6) x 10^22 cm^-2, in
excess of 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 4.5 x 10^-11 (9.9 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.1 (+0.8, -0.6) x 10^22 cm^-2
Galactic foreground: 7.1 x 10^20 cm^-2
Excess significance: 3.1 sigma
Photon index: 2.2 (+/-0.6)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021644.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021644.
This circular is an official product of the Swift-XRT team.
- GCN Circular #35588
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of IKI GRB FuN:
We observed the field of Fermi LAT localization of GRB 240118A (Bissaldi, GCN 35560), which was also detected by Fermi GBM (Fermi GBM team, GCN 35558; Hamburg, GCN 35563), NuSTAR (Grefenstette, GCN 35564), Konus-Wind (Frederiks, GCN 35567), Swift BAT (DeLaunay, GCN 35568), and GRBAlpha (Dafcikova et al., GCN 35580), and the localization area observed by MASTER-Tunka observatory (Lipunov et al., GCN 35561) and Abastumani observatory (Pankov et al., GCN 35572).
Observations started on 2024-01-18 (UT) 14:13:46 with AZT-33IK telescope of Sayan observatory (Mondy) in the R-filter. The observations have been carried out in moderate weather conditions with FWHM of 2.5". We report observations of XRT candidates detected in the Swift TOO program (Evans et al., GCN 35573).
XRT #1 - out of FOV
XRT #2 - matches bright USNO-B1.0 star with R2=9.98 mag
XRT #3 - within the XRT #3 error circle we detect a faint source, which matches SDSS J011408.49+294753.1 source with SDSS DR12 r'= 22.117 and redshift of z_phot = 0.68
XRT #4 - out of FOV
XRT #5 - matches bright Gaia DR3 star with G=6.48 mag
XRT #6 - out of FOV
XRT #7 - out of FOV
Preliminary photometry of the faint source XRT #3 suggested as an X-ray afterglow (Beardmore et al., GCN 35587) is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2024-01-18 14:13:46 0.537932 R 29*120 22.1 0.3 22.1
The photometry is based on nearby USNO-B1.0 stars.
At this time we cannot say anything about the variability of the source. The source at coordinates 01:14:08.48 +29:47:53.2, spatially coinciding with the galaxy SDSS J011408.49+294753.1 with a redshift of 0.68 could be a host galaxy of GRB 240118A.
- GCN Circular #35607
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240118
96191 s after the LAT trigger (Bissaldi et al., GCN Circ. 35560). No optical aft
erglow consistent with the
LAT position or the XRT position (Beardmore et al., GCN Circ. 35587) is detecte
d 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 initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u 96191 103639 3161 >20.8
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).
Previous IAU Circulars 
