February 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37386] Konus-Wind detection of GRB 250215A / EP250215a
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39375 SUBJECT: Konus-Wind detection of GRB 250215A / EP250215a DATE: 25/02/19 15:45:03 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 250215A / EP250215a (Fermi-GBM detection: The Fermi GBM team, GCN 39327; Scotton and Meegan, GCN 39342; EP-WXT detection: Wang et al., GCN 39329; … [View More]INTEGRAL-SPI-ACS detection: Barria et al., GCN 39331; AstroSat-CZTI detection: Tembhurnikar et al., GCN 39334; SVOM/GRM detection: Zheng et al., GCN 39335) triggered Konus-Wind at T0=09130.387 s UT (02:32:10.387). The burst light curve shows a multipeaked structure which starts at ~T0-14 s and has a total duration of ~22 s. The emission is seen up to ~1 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB250215_T09130/ As observed by Konus-Wind, the burst had a fluence of 8.33(-1.97,+2.51)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.054 s, of 5.12(-1.37,+1.66)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). Since a major part of the burst emission was detected before the trigger time and the burst shows a minor spectral evolution, we use the spectrum measured from T0 to T0+8.448 s to estimate the total burst fluence. This spectrum is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.03(-0.54,+0.69), the high energy photon index beta = -2.31(-1.22,+0.30), the peak energy Ep = 130(-36,+80) keV (chi2 = 80/97 dof). The spectrum near the maximum count rate (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 4 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.14(-0.74,+3.47), the high energy photon index beta = -2.35(-0.68,+0.29), the peak energy Ep = 118(-51,+53) keV (chi2 = 18/17 dof). Assuming the redshift z=4.61 (Sanchez-Ramirez et al., GCN 39343) 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 following rest-frame parameters: the isotropic energy release E_iso is 3.35(-0.79,+1.01)x10^53 erg, the peak luminosity L_iso is 1.15(-0.31,+0.37)x10^54 erg/s, the rest-frame peak energy of the time-averaged spectrum Ep,i,z is 660(-250,+298) keV. With the obtained estimates, GRB 250215A is inside 68% prediction band for the 'Amati' and 90% - for the 'Yonetoku' relations derived for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB250215_T09130/GRB250215A_rest_frame.pdf All the quoted errors are at the 68% confidence level. All the quoted values are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/39375. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

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[vsnet-grb-info 37385] SVOM/sb25021804: COLIBRÍ/DDRAGO Confirmation of Variability
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39374 SUBJECT: SVOM/sb25021804: COLIBRÍ/DDRAGO Confirmation of Variability DATE: 25/02/19 14:04:46 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Damien Dornic (CPPM), Antonio de Ugarte Postigo (LAM), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Dalya Akl (AUS), Camila Angulo (UNAM), Sarah Antier (OCA), Jean-Luc Atteia (IRAP), Rosa L. Becerra (U Roma), Nathaniel R. Butler (ASU), Jean-Grégoire Ducoin (CPPM), Francis … [View More]

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[vsnet-grb-info 37384] GRB 250217C: Swift-XRT observations
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39373 SUBJECT: GRB 250217C: Swift-XRT observations DATE: 25/02/19 13:51:26 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (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 … [View More]

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[vsnet-grb-info 37383] SVOM/sb25021804: QSO variability in Liverpool Telescope observations
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39372 SUBJECT: SVOM/sb25021804: QSO variability in Liverpool Telescope observations DATE: 25/02/19 11:37:18 GMT FROM: Rob Eyles-Ferris at U of Leicester <raje1(a)leicester.ac.uk> R. A. J. Eyles-Ferris, P. T. O’Brien and R. L. C. Starling (U of Leicester) report on behalf of a larger collaboration: We observed the field of the SVOM/ECLAIRs transient sb25021804 (Wang et al., GCN 39363) in four pointings covering ~87% of the error area using the IO:O … [View More]

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[vsnet-grb-info 37382] GRB 250217C: COLIBRÍ/DDRAGO Upper Limits on the Optical Counterpart
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39371 SUBJECT: GRB 250217C: COLIBRÍ/DDRAGO Upper Limits on the Optical Counterpart DATE: 25/02/19 07:20:09 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Alan M. Watson (UNAM), Antonio de Ugarte Postigo (LAM), Eleonora Troja (U Roma), Rosa L. Becerra (U Roma), Simone Dichiara (PSU), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Dalya Akl (AUS), Camila Angulo (UNAM), Sarah Antier (OCA), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), … [View More]

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[vsnet-grb-info 37381] GRB 250217C: DDOTI Upper Limits on the Optical Afterglow
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39370 SUBJECT: GRB 250217C: DDOTI Upper Limits on the Optical Afterglow DATE: 25/02/19 05:38:12 GMT FROM: Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra(a)roma2.infn.it> Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Simone Dichiara (Penn State University), Eleonora Troja (U Roma), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), and Margarita … [View More]

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[vsnet-grb-info 37380] GRB 250217C: SVOM/GRM observation
by GCN Circulars 19 Feb '25

19 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39369 SUBJECT: GRB 250217C: SVOM/GRM observation DATE: 25/02/19 03:52:28 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Shi-Jie Zheng, Shao-Lin Xiong, Yue Huang, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Frédéric Piron (LUPM), Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia, Sébastien Guillot (IRAP) report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by a short burst … [View More]

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[vsnet-grb-info 37379] GRB 250217C: Tiled Swift observations
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39368 SUBJECT: GRB 250217C: Tiled Swift observations DATE: 25/02/18 19:30:39 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the IPN GRB 250217C. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00133 Any uncatalogued X-ray sources detected in … [View More]

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[vsnet-grb-info 37378] GRB 250217C: Fermi GBM Observation
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39367 SUBJECT: GRB 250217C: Fermi GBM Observation DATE: 25/02/18 18:55:40 GMT FROM: Jacob Smith at Fermi-GBM Team <jrs0118(a)uah.edu> Jacob Smith (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: At 23:54:41.80 UT on 17 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250217C (trigger 761529286/250217996). which was also detected by AstroSat (M. Tembhurnikar, et al. 2025, GCN 39359) and IPN … [View More]

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[vsnet-grb-info 37377] GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
by GCN Circulars 18 Feb '25

18 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39366 SUBJECT: GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61 DATE: 25/02/18 17:28:03 GMT FROM: Remo Ruffini at ICRA <ruffini(a)icra.it> R. Ruffini, D. Berkimbayev, G. Vereshchagin, R. F. Mohideen Malik, N. Shynggyskhan, M.T. Mirtorabi, J.A. Rueda, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report: GRB 250215A / EP250215A was detected by Fermi (GCN 39327), Einstein Probe (GCN … [View More]

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