March 2024 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 33820] GRB 240320A: Fermi GBM Final Real-time Localization
by GCN Circulars 20 Mar '24

20 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35967 SUBJECT: GRB 240320A: Fermi GBM Final Real-time Localization DATE: 24/03/20 17:40:23 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 17:29:47 UT on 20 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240320A (trigger 732648592.559252 / 240320729). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 150.8, Dec = 63.4 (J2000 degrees, equivalent to J2000 10h 03m, 63d 23'), with a statistical uncertainty of 14.5 degrees. The angle from the Fermi LAT boresight is 55.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240320729/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240320729/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240320729/… View this GCN Circular online at https://gcn.nasa.gov/circulars/35967. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33819] IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a)
by GCN Circulars 19 Mar '24

19 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35966 SUBJECT: IPN triangulation of GRB 240315C (consistent with a fast X-ray transient EP240315a) DATE: 24/03/19 23:33:06 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, E. Burns on behalf of the IPN, and J. DeLaunay, A. Tohuvavohu, S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer on behalf of the Swift-BAT team, report: The long-duration GRB 240315C has been detected by Konus-Wind, in the waiting mode, and Swift (BAT), so far, at about 73000 s UT (20:16:40). The burst was outside the coded field of view of the BAT. We have triangulated it to a Konus-BAT annulus centered at RA(2000)=159.341 deg (10h 37m 22s) Dec(2000)=+10.835 deg (+10d 50' 04") whose radius is 26.696 +/- 26.696 deg (3 sigma). This localization may be improved. The fast X-ray transient EP240315a (Zhang et al., GCN 35931) is inside the annulus and is consisted with the Konus-Wind ecliptic latitude response, lending support to the association of GRB 240315C and the transient. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB240315_T73000/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/35966. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33818] GRB 240317B: Swift/BAT-GUANO Angular Error Correction
by GCN Circulars 19 Mar '24

19 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35965 SUBJECT: GRB 240317B: Swift/BAT-GUANO Angular Error Correction DATE: 24/03/19 19:07:34 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: During the detection of GRB 240317B, Swift was in safe point mode and had an unstable pointing. Due to this, the angular error is larger than previously reported (GCN 35948). We have performed an imaging analysis at the time of the GRB and found Cyg X-1 at an angular offset of ~1 deg. We also attempt to approximately correct the best fit position. The updated BAT position and error is, RA, Dec = 271.95, +38.4 deg which is RA(J2000) = 18h 07m 48.0s Dec(J2000) = +38d 24′ 00.0″ with an estimated uncertainty of ~1 deg radius View this GCN Circular online at https://gcn.nasa.gov/circulars/35965. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33817] Fermi Gamma-ray Burst Monitor trigger 732299243/240316686 is not a GRB
by GCN Circulars 19 Mar '24

19 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35964 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 732299243/240316686 is not a GRB DATE: 24/03/19 14:58:43 GMT FROM: Peter Veres at University of Alabama in Huntsville <veresp(a)gmail.com> P. Veres (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 732299243/240316686 at 16:27:18.18 UT on 16 March 2024, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is due to a solar flare." View this GCN Circular online at https://gcn.nasa.gov/circulars/35964. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33816] X-ray transient EP 240315a: Chandra observations
by GCN Circulars 19 Mar '24

19 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35963 SUBJECT: X-ray transient EP 240315a: Chandra observations DATE: 24/03/19 11:31:23 GMT FROM: Andrew Levan at Radboud University <a.levan(a)astro.ru.nl> A.J. Levan (Radboud & Warwick), P.G. Jonker (Radboud), D.B. Malesani (DAWN/NBI & Radboud), N.R. Tanvir (Leicester), B.P. Gompertz (Birmingham), A. Saccardi (GEPI/Obs. de Paris), A. de Ugarte Postigo (CNRS/OCA & LAM), A. Martin-Carrillo (UCD), D. Perley (LJMU), D. Xu (NAOC), G. Tagliaferri (INAF, Brera), J. Palmerio (GEPI/Obs. de Paris)), K.E. Heintz (DAWN/NBI), K. Wiersema (Hertfordshire), M. Grazia Bernardini (INAF, Brera), M. Ferro (INAF, Brera), P. Jakobbson (U. Iceland), P. D’Avanzo (INAF, Brera), R. Salvaterra (INAF, Milan), S. Vergani (GEPI/Obs. de Paris), G. Pugliese (API, Amsterdam), Y. Julakanti (Leicester) report for the Stargate collaboration: We obtained observations of EP240315a (Zhang et al., GCN 35931) with the Chandra X-ray observatory. Observations began at 20:13 on 18 March 2024, 72 hours after the flare detection. The source was placed at the default aim point on the S3 chip for a total exposure time of 10 ks. At the location of AT2024eju (Srivastav et al., GCN 35932) we clearly detect an X-ray counterpart with a source flux of (3.3+/- 0.5)e-3 cps. For the same spectral parameters inferred from the EP follow-up telescope observations, and at z = 4.859 (Saccardi et al., GCN 35936; Quirola-Vásquez et al., GCN 35960) the source has an X-ray luminosity of L_X ~ 2e46 erg/s . The decay from the EP follow-up telescope observations at t+42 hours (Chen et al. GCN 35951) to the Chandra exposure at t+72 hours post burst is ~t^-1.6. Both of these are typical of the properties seen in long GRBs, although the luminosity is towards the higher end. We thank Pat Slane, Vinay Kashyap and the staff of the CXC for their excellent support and rapid scheduling of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/35963. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33815] X-ray transient EP240315a: GTC/HiPERCAM photometry
by GCN Circulars 18 Mar '24

18 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35962 SUBJECT: X-ray transient EP240315a: GTC/HiPERCAM photometry DATE: 24/03/18 22:39:47 GMT FROM: P.G. Jonker at Radboud University <p.jonker(a)astro.ru.nl> P. G. Jonker (Radboud Univ.), S. Littlefair (Sheffield Uni.), F. E. Bauer (PUC), A. J. Levan (Radboud Univ. & Warwick Univ.), D. B. Malesani (DAWN/NBI and Radboud Univ.), Maria E. Ravasio (Radboud Univ.), M.A.P. Torres (IAC), V. Dhillon (Sheffield Uni.), D. García Álvarez (GTC), A. M. García (GTC), on behalf of a larger collaboration: We observed the optical counterpart AT2024eju (Srivastav et al., GCN 35932) of the fast X-ray transient EP240315a reported by the Einstein Probe WXT instrument (Zhang et al., GCN 35931), using the GTC/HiPERCAM imager. We obtained 80 exposures of 30 seconds each in u’g’r’i’z’ simultaneously. The observations started at 21:10 UT on Mar 17, 2024. We clearly detected the source in the r’, i’, and z’ bands. The z’-band magnitude was 22 (AB mag). We acknowledge the excellent support from the GTC staff. View this GCN Circular online at https://gcn.nasa.gov/circulars/35962. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33814] X-ray transient EP240315a: MeerKAT radio detection
by GCN Circulars 18 Mar '24

18 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35961 SUBJECT: X-ray transient EP240315a: MeerKAT radio detection DATE: 24/03/18 21:47:26 GMT FROM: Francesco Carotenuto at University of Oxford <francesco.carotenuto(a)physics.ox.ac.uk> F. Carotenuto, J. Bright (Oxford), P. G. Jonker (Radboud), R. Fender, L. Rhodes (Oxford) report on behalf of a larger collaboration: We observed the new Fast X-ray Transient EP240315a (Zhang et al., GCN 35931) with the MeerKAT radio telescope at 3.0 GHz for a total of 1 hour starting on 18 March 2024 at 16:53 UTC. J1939-6342 and 3C237 were used as flux and complex gain calibrators, respectively. Using the South African Radio Astronomy Observatory Science Data Pipeline image, we find an unresolved source at the position of the optical counterpart of the FXT AT2024eju (Srivastav et al., GCN 35932) with a flux density of ~30uJy/beam. The rms noise in the field is 8.5 uJy/beam. Further MeerKAT observations are planned. We thank the staff at the South African Radio Astronomy Observatory for the rapid scheduling of these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/35961. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33813] X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation
by GCN Circulars 18 Mar '24

18 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35960 SUBJECT: X-ray transient EP240315a: GTC/OSIRIS spectroscopic redshift confirmation DATE: 24/03/18 21:46:12 GMT FROM: P.G. Jonker at Radboud University <p.jonker(a)astro.ru.nl> J. Quirola-Vásquez (Radboud Univ.), P.G. Jonker (Radboud Univ.), A. J. Levan (Radboud Univ. & Warwick Univ.), F. E. Bauer (PUC), D. B. Malesani (DAWN/NBI and Radboud Univ.), Maria E. Ravasio (Radboud Univ.), M.A.P. Torres (IAC), A. M. García (GTC) on behalf of a larger collaboration: We observed the optical counterpart AT2024eju (Srivastav et al., GCN 35932) of the fast X-ray transient EP240315a reported by the Einstein Probe WXT instrument (Zhang et al., GCN 35931) and followed-up by its FXT instrument (Chen et al., GCN 35951), using the GTC/OSIRIS spectrograph. Our spectra cover the wavelength range 5100-10000 AA and consist of 3 exposures of 1200 seconds each. Observations started at 22:54:51 UT on Mar 16, 2024 (~27 hr after the X-ray trigger). We detect a faint trace, with the Lyman break and several absorption features which we identify as due to OIλ1302.17, SiIIλ1304.37, and SiIVλλ1393.76/1402.77. Therefore, we confirm the redshift identification of z = 4.859 determined by Saccardi et al. (GCN 35936) using VLT/X-shooter. We acknowledge the excellent support from the GTC staff. View this GCN Circular online at https://gcn.nasa.gov/circulars/35960. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33812] GRB 240318A: Glowbug gamma-ray detection
by GCN Circulars 18 Mar '24

18 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35959 SUBJECT: GRB 240318A: Glowbug gamma-ray detection DATE: 24/03/18 19:01:13 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 240318A, which was also detected by Fermi/GBM (GCN 35949). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-18 02:51:00.832 with a duration of 5.2 s and a total significance of about 14.4 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 poorly constrained power-law index and a cutoff energy ("Epeak") of 163 keV. The modeled 10-10000 keV fluence is 7.6e-07 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/35959. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 33811] GRB 240317C: Glowbug gamma-ray detection
by GCN Circulars 18 Mar '24

18 Mar '24

TITLE: GCN CIRCULAR NUMBER: 35958 SUBJECT: GRB 240317C: Glowbug gamma-ray detection DATE: 24/03/18 18:59:53 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 240317C. Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-03-17 20:20:25.304 with a duration of 8.2 s and a total significance of about 25.8 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 poorly constrained power-law index and a cutoff energy ("Epeak") of 216 keV. The modeled 10-10000 keV fluence is 1.1e-06 erg/cm^2. The best-fit localization is RA, Decl. (J2000, deg) = 314.8, -60.6 with a radius of 18.9 deg (95% confidence), with a highly uncertain systematic uncertainty. 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/35958. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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