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

[vsnet-grb-info 35255] LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification
by GCN Circulars 31 Aug '24

31 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37357 SUBJECT: LIGO/Virgo/KAGRA S240830gn: Updated Sky localization and EM Bright Classification DATE: 24/08/31 00:30:55 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), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S240830gn (GCN Circular 37354). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S240830gn Based on posterior support from parameter estimation [1], under the assumption that the candidate S240830gn is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [2] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [2] 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%. For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 410 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1118 +/- 297 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/. [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380 [2] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe View this GCN Circular online at https://gcn.nasa.gov/circulars/37357. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35254] GRB 240829A: Swift-BAT refined analysis
by GCN Circulars 31 Aug '24

31 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37356 SUBJECT: GRB 240829A: Swift-BAT refined analysis DATE: 24/08/31 00:25:46 GMT FROM: Michael Moss at NASA GSFC <mikejmoss3(a)gmail.com> D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240829A (trigger #1251252) (Laha, et al., GCN Circ. 37333). The BAT ground-calculated position is RA, Dec = 143.079, -18.687 deg which is RA(J2000) = 09h 32m 18.9s Dec(J2000) = -18d 41' 13.0" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 15%. The mask-weighted light curve displays a combination of two to three dim fast- rise-exponential-decay pulses. The T90 (15-350 keV) is 43.20 +- 10.47 sec (estimated error including systematics). The time-averaged spectrum from T-12.53 to T+51.47 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.66 +- 0.11. The fluence in the 15-150 keV band is 3.8 +- 0.3 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+10.97 sec in the 15-150 keV band is 0.0 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Swift did not slew to the BAT position due to the burst being sun constrained. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1251252 View this GCN Circular online at https://gcn.nasa.gov/circulars/37356. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35253] GRB 240825A: Swift-BAT refined analysis
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37355 SUBJECT: GRB 240825A: Swift-BAT refined analysis DATE: 24/08/30 23:32:53 GMT FROM: Amy <yarleen(a)gmail.com> M. J. Moss (GSFC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+800 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240825A (trigger #1250617) (Gupta et al., GCN Circ. 37274). The BAT ground-calculated position is RA, Dec = 344.570, 1.019 deg which is RA(J2000) = 22h 58m 16.9s Dec(J2000) = +01d 01' 08.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%. The mask-weighted light curve shows a very bright FRED-like pulse that starts at ~T0 and peaks at ~T+1.8 s. In addition, there are some secondary pulses on top of the main FRED-like structure. The main structure ends at ~T+10 s, and there is a long tail emission that lasts till ~T+300 s. T90 (15-350 keV) is 57.20 +- 8.57 sec (estimated error including systematics). The time-averaged spectrum from T-0.04 to T+216.76 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.20 +- 0.03. The fluence in the 15-150 keV band is 2.5 +- 0.04 x 10^-05 erg/cm2. The 1-sec peak photon flux measured from T+1.44 sec in the 15-150 keV band is 100.0 +- 1.7 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1250617 View this GCN Circular online at https://gcn.nasa.gov/circulars/37355. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35252] LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37354 SUBJECT: LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate DATE: 24/08/30 21:43:31 GMT FROM: Brice Williams at LIGO-Hanford/Washington State University <bricemichael.williams(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S240830gn during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-08-30 21:11:20.392 UTC (GPS time: 1409087498.392). The candidate was found by the GstLAL [1], MBTA [2], and PyCBC Live [3] analysis pipelines. S240830gn is an event of interest because its false alarm rate, as estimated by the online analysis, is 6.3e-10 Hz, or about one in 50 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S240830gn The classification of the GW signal, in order of descending probability, is BBH (89%), NSBH (11%), Terrestrial (<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%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] 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 8%. Two 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 [5], distributed via GCN notice about 31 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 825 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1236 +/- 337 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/. [1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [2] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 View this GCN Circular online at https://gcn.nasa.gov/circulars/37354. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35251] LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37354 SUBJECT: LIGO/Virgo/KAGRA S240830gn: Identification of a GW compact binary merger candidate DATE: 24/08/30 21:43:31 GMT FROM: Brice Williams at LIGO-Hanford/Washington State University <bricemichael.williams(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S240830gn during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-08-30 21:11:20.392 UTC (GPS time: 1409087498.392). The candidate was found by the GstLAL [1], MBTA [2], and PyCBC Live [3] analysis pipelines. S240830gn is an event of interest because its false alarm rate, as estimated by the online analysis, is 6.3e-10 Hz, or about one in 50 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S240830gn The classification of the GW signal, in order of descending probability, is BBH (89%), NSBH (11%), Terrestrial (<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%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] 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 8%. Two 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 [5], distributed via GCN notice about 31 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 825 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1236 +/- 337 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/. [1] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [2] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 View this GCN Circular online at https://gcn.nasa.gov/circulars/37354. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35250] GRB 240825A: MeerKAT detection
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37353 SUBJECT: GRB 240825A: MeerKAT detection DATE: 24/08/30 21:26:36 GMT FROM: Genevieve Schroeder at Northwestern University <genevieveschroeder(a)u.northwestern.edu> C. Peña (University of Utah), G. Schroeder (Northwestern University), T. Laskar (University of Utah), K. D. Alexander (University of Arizona), C. Christy (University of Arizona), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), P. Schady (University of Bath), S. de Wet (University of Cape Town) and P. Groot (Radboud University) report on behalf of a larger collaboration: “We observed GRB 240825A (Gupta et al., GCN 37274) with the MeerKAT radio telescope at 1.3 GHz and 3 GHz beginning on 2024 August 29 at 20:34 UT (100.7 hours post burst). In preliminary analysis, we detect the radio counterpart (Laskar et al., GCN 37314) at 1.3 GHz with a flux density of F ~ 0.16 mJy at the position: RA (J2000) = 22:58:17.32 Dec (J2000) = +01:01:35.74 with uncertainty ~1.3" in each coordinate, consistent with the X-ray position (Evans et al., GCN 37290), optical position (Gupta et al., GCN 37274; Jiang et al., GCN 37275; Dutton et al., GCN 37276; Odeh et al., GCN 37277; Li et al., GCN 37280; Evans et al., GCN 37290; Leonini et al., GCN 37291; Kuin et al., GCN 37296), and radio position (Laskar et al., GCN 37314, Peña et al., GCN 37322). Further observations are planned. We thank the MeerKAT staff for scheduling and executing these observations. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.” View this GCN Circular online at https://gcn.nasa.gov/circulars/37353. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35249] GRB 240828B: J-band upper limit from WINTER
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37352 SUBJECT: GRB 240828B: J-band upper limit from WINTER DATE: 24/08/30 19:23:34 GMT FROM: Benjamin Schneider at MIT <bschn(a)mit.edu> Benjamin Schneider (MIT), Geoffrey Mo (MIT), Robert Stein (Caltech), Viraj Karambelkar (Caltech), Nathan Lourie (MIT), Danielle Frostig (MIT), Tomas Ahumada (Caltech), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report: We observed the field of the SVOM/ECLAIRs GRB 240828B (Le Provost et al, GCN 37318) in the near-infrared J-band with the Palomar 1-m telescope, equipped with the 1-square degree WINTER camera (Lourie et al. 2020). Our observations began at 2024-08-29T09:00:15 UTC (~20 hours after the GRB trigger) and consisted of 30x120s exposures. The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar, https://doi.org/10.5281/zenodo.10888436) with image subtraction performed relative to J-band images from the UKIRT Hemisphere survey (Dye et al., 2017). In our stacked and subtracted images, we do not detect any new source within the Swift/XRT error circle (Page et al., GCN 37334) down to a 5-sigma depth of J ~ 19.2 mag (AB). The magnitude is not corrected for Galactic extinction. WINTER (Wide-field INfrared Transient ExploreR) is a partnership between MIT and Caltech, housed at Palomar Observatory, and funded by NSF MRI, NSF AAG, the David and Lucile Packard Foundation, and the MIT Kavli Institute for Astrophysics and Space Research. View this GCN Circular online at https://gcn.nasa.gov/circulars/37352. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35248] Fermi trigger No 746684112: Global MASTER-Net observations report
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37351 SUBJECT: Fermi trigger No 746684112: Global MASTER-Net observations report DATE: 24/08/30 12:30:57 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-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB240830.18 (trigger No 746684112,20h 57m 16.80s , +65d 06m 36.0s, R=50) errorbox 25893 sec after notice time and 25925 sec after trigger time at 2024-08-30 11:27:13 UT, with upper limit up to 16.6 mag. Observations started at twilight. The observations began at zenith distance = 41 deg. The sun altitude is -11.0 deg. The galactic latitude b = 13 deg., longitude l = 102 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2581388 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 25956 | 2024-08-30 11:27:13 | MASTER-Amur | (13h 51m 38.47s , +56d 11m 37.4s) | C | 60 | 15.7 | 25956 | 2024-08-30 11:27:13 | MASTER-Amur | (13h 38m 12.84s , +55d 45m 03.2s) | C | 60 | 15.5 | 26129 | 2024-08-30 11:30:06 | MASTER-Amur | (00h 46m 55.28s , +77d 13m 08.0s) | C | 60 | 16.6 | 26129 | 2024-08-30 11:30:06 | MASTER-Amur | (01h 18m 59.38s , +77d 38m 40.8s) | C | 60 | 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/37351. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35247] GRB 240828B: GMG Optical Upper Limit
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37350 SUBJECT: GRB 240828B: GMG Optical Upper Limit DATE: 24/08/30 09:03:28 GMT FROM: wangbaiting(a)ynao.ac.cn B.-T. Wang, R.-Z. Li, F.-F. Song, J. Mao, K.-X. Lu and J.-M. Bai (YNAO, CAS) report: We observed the field of GRB 240828B (SVOM/ECLAIRs, T0 at 2024-08-28T13:12:43, GCN 37318) using the GMG-2.4m telescope at the Lijiang Observatory. The observation began at 2024-08-28T19:21:41.934, about 6.13 hours after the trigger. No new reliable optical counterpart was detected within the 2.6-arcsec Swift/XRT error circle (GCN 37334), down to a 5-sigma limiting magnitude of sdss-r ～ 21.7 mag, derived from calibration against the Pan-STARRS DR1 field stars. We acknowledge the staff at the Lijiang Observatory for conducting the observation. View this GCN Circular online at https://gcn.nasa.gov/circulars/37350. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 35246] GRB 240828A: KAIT continued optical observations
by GCN Circulars 30 Aug '24

30 Aug '24

TITLE: GCN CIRCULAR NUMBER: 37349 SUBJECT: GRB 240828A: KAIT continued optical observations DATE: 24/08/30 07:06:20 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, continued observing the optical afterglow of GRB 240828A (Zheng et al., GCN 37339; Moskvitin et al., GCN 37344) starting at ~1.54 days after the burst. A set of 31x60s clear (roughly R) filter images were obtained. The afterglow was clearly detected in our coadd image and we measure its brightness has faded to be 20.2 +/- 0.2 mag. View this GCN Circular online at https://gcn.nasa.gov/circulars/37349. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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