August 2023 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 32458] LIGO/Virgo/KAGRA S230831e: Updated Sky localization
by GCN Circulars 31 Aug '23

31 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34606 SUBJECT: LIGO/Virgo/KAGRA S230831e: Updated Sky localization DATE: 23/08/31 12:41:35 GMT FROM: Soichiro Morisaki at U. of Tokyo <soichiro.morisaki(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S230831e (GCN Circular 34605). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S230831e For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 3803 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 4900 +/- 2126 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/userguide/. [1] Ashton et al. ApJS 241, 27 (2019) --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32457] LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
by GCN Circulars 31 Aug '23

31 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34605 SUBJECT: LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate DATE: 23/08/31 02:59:54 GMT FROM: surojitsaha(a)gapp.nthu.edu.tw The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S230831e during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2023-08-31 01:54:14.068 UTC (GPS time: 1377482072.068). The candidate was found by the CWB [1], GstLAL [2], MBTA [3], PyCBC Live [4], and SPIIR [5] analysis pipelines. S230831e is an event of interest because its false alarm rate, as estimated by the online analysis, is 2e-08 Hz, or about one in 1 year, 7 months. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S230831e The classification of the GW signal, in order of descending probability, is BBH (98%), Terrestrial (2%), NSBH (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [6] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [6] Both HasNS and HasRemnant consider the support of several neutron star equations of state. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is <1%. Three sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [7], distributed via GCN notice about 23 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [7], distributed via GCN notice about 36 seconds after the candidate event time. * bayestar.multiorder.fits,2, an initial localization generated by BAYESTAR [7], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,2. For the bayestar.multiorder.fits,2 sky map, the 90% credible region is 3326 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 6672 +/- 2201 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/userguide/. [1] Klimenko et al. PRD 93, 042004 (2016) [2] Tsukada et al. arXiv:2305.06286 (2023) and Ewing et al. arXiv:2305.05625 (2023) [3] Aubin et al. CQG 38, 095004 (2021) [4] Dal Canton et al. ApJ 923, 254 (2021) [5] Chu et al. PRD 105, 024023 (2022) [6] Chatterjee et al. ApJ 896, 54 (2020) [7] Singer & Price PRD 93, 024013 (2016) --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32456] GRB 230827B: Glowbug gamma-ray detection
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34604 SUBJECT: GRB 230827B: Glowbug gamma-ray detection DATE: 23/08/30 14:51:11 GMT FROM: matthew.kerr(a)gmail.com M. Kerr, C.C. Cheung, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report: The Glowbug [1,2] gamma-ray telescope, operating on the International Space Station, reports the detection of GRB 230827B, which was also detected by Fermi/GBM, VZLUSAT-2, GECAM-B (trigger 215), INTEGRAL/SPI-ACS, and CALET (GCN 34584, 34585, 34593). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-08-27 06:08:30.320 with a duration of 10.6 s and a total significance of about 57.8 sigma. The light-curve comprises two similar FRED pulses with widths of about 1s, separated by about 5s, each with tails of faint emission lasting about 5s. 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 272 keV. The modeled 10-10000 keV fluence is 1.3e-05 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. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32455] GRB 230827A: Glowbug gamma-ray detection
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34603 SUBJECT: GRB 230827A: Glowbug gamma-ray detection DATE: 23/08/30 14:50:54 GMT FROM: matthew.kerr(a)gmail.com M. Kerr, C.C. Cheung, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report: The Glowbug [1,2] gamma-ray telescope, operating on the International Space Station, reports the detection of GRB 230827A, which was also detected by Fermi/GBM, GRBAlpha, Swift/BAT-GUANO, VZLUSAT-2, and INTEGRAL/SPI-ACS (GCN 34575, 34583, 34587, 34588). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-08-27 18:17:50.272 with a duration of 100.4 s and a total significance of about 78.2 sigma. The light curve comprises two broad peaks each of about 50s duration, with the peak flux observed roughly at the center of the first pulse. 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=-0.5 and a cutoff energy ("Epeak") of 371 keV. The modeled 10-10000 keV fluence is 2.9e-05 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. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32454] GRB 230826A: Glowbug gamma-ray detection
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34602 SUBJECT: GRB 230826A: Glowbug gamma-ray detection DATE: 23/08/30 14:50:37 GMT FROM: matthew.kerr(a)gmail.com M. Kerr, C.C. Cheung, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (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 230826A, which was also detected by Fermi/GBM, Swift/BAT, GRBAlpha, and VZLUSAT-2 (GCN 34564, 34565, 34572, 34586). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-08-26 19:32:44.336 with a duration of 12.3 s and a total significance of about 29.9 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 138 keV. The modeled 10-10000 keV fluence is 1.5e-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. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32453] GRB 230827B: Swift-XRT afterglow detection
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34601 SUBJECT: GRB 230827B: Swift-XRT afterglow detection DATE: 23/08/30 13:26:29 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 230827B (GCN Circ. 34584), collecting 3.6 ks of Photon Counting (PC) mode data between T0+231.3 ks and T0+249.7 ks. An uncatalogued X-ray source is detected consistent with being within 9.9 arcsec of the position of ZTF23abaanxz/AT2023qxj (GCN Circ. 34574) and is believed to be the afterglow. Using 3821 s of PC mode data and 4 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 = 299.63944, +54.46318 which is equivalent to: RA (J2000): 19h 58m 33.47s Dec(J2000): +54d 27' 47.5" with an uncertainty of 2.6 arcsec (radius, 90% confidence). This position is 0.8 arcsec from the ZTF position. The light curve is consistent with a constant source of mean count rate 7.0e-02 ct/sec. A power-law fit gives an index of 2.490 (+0.015, -2.990). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.59 (+0.33, -0.30). The best-fitting absorption column is 4.0 (+2.1, -1.0) x 10^21 cm^-2, consistent with the Galactic value of 3.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.0 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.0 (+2.1, -1.0) x 10^21 cm^-2 Galactic foreground: 3.0 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.59 (+0.33, -0.30) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021620. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021620. This circular is an official product of the Swift-XRT team. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32452] LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34600 SUBJECT: LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate DATE: 23/08/30 06:09:21 GMT FROM: J. C. Driggers at California Institute of Technology, LIGO Hanford Observatory <jenne(a)caltech.edu> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: This candidate was originally retracted on 15 July 2023 in GCN Circular 34219, and it still remains not a candidate of interest. Due to human error, a Retraction Notice for this candidate was sent out again today. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32451] LIGO/Virgo/KAGRA S230830b: Retraction of GW compact binary merger candidate
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34599 SUBJECT: LIGO/Virgo/KAGRA S230830b: Retraction of GW compact binary merger candidate DATE: 23/08/30 05:42:40 GMT FROM: apratim.ganguly(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: The trigger S230830b is no longer considered to be a candidate of interest. There were data quality issues and the detection pipeline expert recommended a retraction. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32450] LIGO/Virgo/KAGRA S230820bq: Updated Sky localization
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34598 SUBJECT: LIGO/Virgo/KAGRA S230820bq: Updated Sky localization DATE: 23/08/29 23:14:39 GMT FROM: Anjali Balasaheb Yelikar at Rochester Institute of Technology <ay2016(a)g.rit.edu> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We have conducted further analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S230820bq (GCN Circular 34504). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S230820bq For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 1373 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 3600 +/- 1437 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/userguide/. [1] Ashton et al. ApJS 241, 27 (2019) --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32449] GRB 230812B: Spectroscopic detection of the associated SN 2023pel.
by GCN Circulars 30 Aug '23

30 Aug '23

TITLE: GCN CIRCULAR NUMBER: 34597 SUBJECT: GRB 230812B: Spectroscopic detection of the associated SN 2023pel. DATE: 23/08/29 22:49:42 GMT FROM: J. F. Agui Fernandez at IAA-CSIC <feli(a)iaa.es> J. F. Agui Fernandez (IAA-CSIC), A. de Ugarte Postigo (OCA-CNRS), C. C. Thoene (ASU-CAS), D. B. Malesani (Radboud and DAWN/NBI), L. Izzo (INAF-OACN and DARK/NBI) and A. L. Cabrera Lavers (GTC, IAC) report: We observed the long GRB 230812B*/*SN 2023pel (Fermi GBM Team GCN, 34386; Roberts et al. GCN34391, Scotton et al. GCN 34392, Zheng & Filippenko GCN 34395, Beardmore et al. GCN 34400) on August 24, 2023 at 21.79 hours UT, ~12.12 days after the GRB detection, with OSIRIS+ in spectroscopy mode at the 10.4m GTC Telescope located at Roque de los Muchachos, Canary Islands, Spain. The spectrum covers the wavelength range from 3700 to 7500 AA. In a preliminary analysis, the spectrum shows the characteristic undulations of a GRB-SN spectrum. Our spectrum is well matched to the spectrum of SN 1998bw at a comparable rest-frame epoch (Patat et al. 2001, ApJ, 555, 900). We can thus conclusive determine the presence of a SN associated with GRB 230812B, confirming previous claims based on photometric evidence (Moskvitin & Spiridonova GCN 34475, Moskvitin & Goranskij GCN 34496, Kumar et al. GCN 34500, Turpin et al. GCN 34508, Kumar et al. GCN 34516, Pankov et al. GCN 34519). We acknowledge excellent support from the GTC staff. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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