TITLE: GCN CIRCULAR
NUMBER: 36006
SUBJECT: IBAS Alert n.10651 not a GRB
DATE: 24/04/01 17:51:42 GMT
FROM: Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti(a)inaf.it>
Sandro Mereghetti (INAF, IASF-Milano) reports
The INTEGRAL IBAS Alert n.10651 is not due to a GRB
View this GCN Circular online at https://gcn.nasa.gov/circulars/36006.
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TITLE: GCN CIRCULAR
NUMBER: 36005
SUBJECT: IceCube-240327B: Upper limits from a search for additional neutrino events in IceCube
DATE: 24/04/01 17:47:36 GMT
FROM: Alicia Mand at IceCube/UW-Madison <aemand(a)wisc.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-240327B (https://gcn.nasa.gov/circulars/35984) in a time range of 1000 seconds centered on the alert event time (2024-03-27 16:04:10.470 UTC to 2024-03-27 16:20:50.470 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-240327B. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-240327B ranges from 1.4e-01 to 1.5e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 2e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert event time (2024-03-26 16:12:30.470 UTC to 2024-03-28 16:12:30.470 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-240327B is 1.6e-01 GeV cm^-2 in a 2 day time window.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu.
[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
View this GCN Circular online at https://gcn.nasa.gov/circulars/36005.
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TITLE: GCN CIRCULAR
NUMBER: 36004
SUBJECT: IceCube-240327A: Upper limits from a search for additional neutrino events in IceCube
DATE: 24/04/01 17:46:48 GMT
FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-240327A (https://gcn.nasa.gov/circulars/35983) in a time range of 1000 seconds centered on the alert event time (2024-03-27 10:56:29.920 UTC to 2024-03-27 11:13:09.920 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-240327A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-240327A is 1.3e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 1e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert event time (2024-03-26 11:04:49.920 UTC to 2024-03-28 11:04:49.920 UTC). In this case, we report a p-value of 0.24, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-240327A is 1.5e-01 GeV cm^-2 in a 2 day time window.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu.
[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
View this GCN Circular online at https://gcn.nasa.gov/circulars/36004.
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TITLE: GCN CIRCULAR
NUMBER: 36003
SUBJECT: Integral GRB240401.69: Global MASTER-Net observations report
DATE: 24/04/01 17:19:26 GMT
FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru>
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-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) was pointed to the Integral GRB240401.69 (trigger No 10651,05h 34m 06.25s , +22d 00m 11.5s, R=0.0546667) errorbox 946 sec after notice time and 961 sec after trigger time at 2024-04-01 16:54:58 UT, with upper limit up to 16.4 mag. Observations started at twilight. The observations began at zenith distance = 36 deg. The sun altitude is -8.8 deg.
The galactic latitude b = -5 deg., longitude l = 185 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2411905
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
1051 | MASTER-Tavrida | C | 180 | 14.9 |
1241 | MASTER-Tavrida | C | 180 | 15.3 |
1428 | MASTER-Tavrida | C | 180 | 15.7 |
1615 | MASTER-Tavrida | C | 180 | 15.9 |
1802 | MASTER-Tavrida | C | 180 | 16.2 |
1991 | MASTER-Tavrida | C | 180 | 16.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36003.
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TITLE: GCN CIRCULAR
NUMBER: 36002
SUBJECT: GRB 240329A: Glowbug gamma-ray detection
DATE: 24/04/01 15:06:52 GMT
FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil>
C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (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 240329A, which was also detected by Fermi/GBM (GCN 35993, 35994), GRBAlpha (GCN 35997), and AstroSat/CZTI (GCN 35999).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-29 21:43:05.936 with a duration of 7.1 s and a total significance of about 42 sigma. The light curve comprises two primary peaks at ~T0+1s and ~T0+4s, with a faint peak at ~T0+7s.
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.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36002.
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TITLE: GCN CIRCULAR
NUMBER: 36001
SUBJECT: GRB 240324A: AstroSat CZTI detection of a short burst
DATE: 24/04/01 10:31:52 GMT
FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar24(a)gmail.com>
J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/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 the detection of a short-duration GRB 240324A. Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst.
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-03-24 03:35:14.25 UTC. The measured peak count rate associated with the burst is 365 (+162, -42) counts/s above the background in the combined data of all quadrants, with a total of 207 (+60, -59) counts. The local mean background count rate was 360 (+12, -14) counts/s. Using cumulative rates, we measure a T90 of 0.79 (+0.29, -0.27) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-03-24 03:35:13.39 UTC. The measured peak count rate associated with the burst is 660 (+79, -86) counts/s above the background in the combined data of all quadrants, with a total of 1191 (+246, -255) counts. The local mean background count rate was 1665 (+9, -10) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb
View this GCN Circular online at https://gcn.nasa.gov/circulars/36001.
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TITLE: GCN CIRCULAR
NUMBER: 36000
SUBJECT: GRB 240331A: AstroSat CZTI detection
DATE: 24/04/01 10:25:36 GMT
FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar24(a)gmail.com>
J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/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 the detection of a long-duration GRB 240331A which was also detected by the Fermi-GBM (Fermi-GBM Team, GCN Circ. 35998).
The source was 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 2024-03-31 23:55:20.01 UTC. The measured peak count rate associated with the burst is 266 (+69, -53) counts/s above the background in the combined data of all quadrants, with a total of 1926 (+501, -548) counts. The local mean background count rate was 1448 (+8, -9) counts/s. We measure a T90 of 20 (+2, -6) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb
View this GCN Circular online at https://gcn.nasa.gov/circulars/36000.
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TITLE: GCN CIRCULAR
NUMBER: 35999
SUBJECT: GRB 240329A: AstroSat CZTI detection
DATE: 24/04/01 09:56:46 GMT
FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar24(a)gmail.com>
J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/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 the detection of a long-duration GRB 240329A which was also detected by Fermi GBM (Fermi-GBM team, GCN Circ. 35993), and GRBAlpha (Dafcikova et al., GCN Circ. 35997).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2024-03-29 21:43:08.05 UTC. The measured peak count rate associated with the burst is 481 (+186, -13) counts/s above the background in the combined data of all quadrants, with a total of 860 (+162, -170) counts. The local mean background count rate was 326 (+6, -8) counts/s. Using cumulative rates, we measure a T90 of 4.12 (+2.37, -0.59) s.
The source 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 2024-03-29 21:43:10.08 UTC. The measured peak count rate associated with the burst is 245 (+67, -51) counts/s above the background in the combined data of all quadrants, with a total of 898 (+288, -307) counts. The local mean background count rate was 1418 (+4, -5) counts/s. We measure a T90 of 7.53 (+3.73, -3.85) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb
View this GCN Circular online at https://gcn.nasa.gov/circulars/35999.
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