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

[vsnet-grb-info 36738] EP241217A: J band upper limit by SYSU 80cm telescope
by GCN Circulars 31 Dec '24

31 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38736 SUBJECT: EP241217A: J band upper limit by SYSU 80cm telescope DATE: 24/12/31 03:09:17 GMT FROM: lijj328(a)mail2.sysu.edu.cn Jin-Ji Li, Zhong-Nan Dong, Wei-Sen Huang, Jia-Qi Lin, Pu Lin, Hao-Nan Yang, Yan Yu, Hao-Ran Zhang, Rong-Feng Shen, Bin Ma (Sun Yat-sen University) report on behalf of the SYSU 80cm telescope team: We observed the field of the fast X-ray transient EP241217A (Zhou et al., GCN 38586), which was also detected by Swift-XRT (Williams et al., GCN 38596), using the Sun Yat-sen University 80cm telescope, with 130 × 20 s exposures in J band. Our observations began at 2024-12-18 17:51:36 UTC, 36.26 hours after the EP trigger. We did not detect any counterpart in the stacked images at the position of the optical afterglow (Levan et al., GCN 38587; Izzo et al., GCN 38588; Fan et al., GCN 38592; Jin et al., GCN 38607; Mohan et al., GCN 38612; Zhu et al., GCN 38613; Bochenek et al., GCN 38615; Liu et al., GCN 38636), down to a 5-sigma depth of J ~ 17.8 Vega magnitudes. View this GCN Circular online at https://gcn.nasa.gov/circulars/38736. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36737] LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
by GCN Circulars 31 Dec '24

31 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38735 SUBJECT: LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate DATE: 24/12/31 00:31:03 GMT FROM: JeongCho Kim at Seoul National University <jeongcho.kim(a)ligo.org> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241230ev during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-12-30 23:36:18.067 UTC (GPS time: 1419636996.067). The candidate was found by the CWB [1], GstLAL [2], and MBTA [3] analysis pipelines. S241230ev is an event of interest because its false alarm rate, as estimated by the online analysis, is 2.2e-08 Hz, or about one in 1 year, 5 months. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241230ev 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%. [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 <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 [5], distributed via GCN notice about 30 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 36 seconds after the candidate event time. * bayestar.multiorder.fits,2, 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,2. For the bayestar.multiorder.fits,2 sky map, the 90% credible region is 1403 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5607 +/- 1725 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] Klimenko et al. PRD 93, 042004 (2016) doi:10.1103/PhysRevD.93.042004 [2] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [3] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [4] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [5] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38735. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36736] GRB 241229B: SAO RAS optical upper limit
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38734 SUBJECT: GRB 241229B: SAO RAS optical upper limit DATE: 24/12/30 21:20:15 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova (SAO RAS), A. A. Volnova and A. S. Pozanenko (IKI RAS) report on behalf of the GRB follow-up team. We observed the field of GRB 241229B (Fermi GBM Team, GCN 38698; D'Ai et al., GCN 38699) with the 1-m telescope of SAO RAS, Zeiss-1000 equipped with the CCD-photometer on December 30, 14:47:58--16:04:24 UT, t_mid - T0 = 1.5763 days. We obtained 12 x 300 sec. images in Rc band. In the stacked image we did not detected OT discovered by SVOM/VT team (GCN 38729) and confirmed by Volnova et al., (GCN 38732) down to the limiting magnitude of R_lim = 22.3 (based on the same nearby PS1 stars, magnitudes were converted with the Lupton 2005 equations). View this GCN Circular online at https://gcn.nasa.gov/circulars/38734. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36735] GRB 241228B: SAO RAS optical observations
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38733 SUBJECT: GRB 241228B: SAO RAS optical observations DATE: 24/12/30 21:08:56 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova, Yu. V. Sotnikova (SAO RAS), A. Volnova, A. Pozanenko (IKI), A. Ghosh, S. Razzaque (CAPP, University of Johannesburg), report on behalf of the GRB follow-up team. We observed the field of GRB 241228B discovered by Fermi (Fermi GBM team, GCN 38682; Scotton and Meegan, GCN 38714), Swift (Evans, GCN 38688; Burrows et al., GCN 38713) with the 1-m telescope of SAO RAS Zeiss-1000 equipped with the CCD-photometer on December 29, 21:49:11 -- 22:57:57 UT (t_mid - T0 = 1.7573 days). We obtained 12 x 300 sec. images in Rc band. The GOTO24jmz optical counterpart (Kumar et al., GCN 38684, GCN 38691; An et al. GCN 38687; Ortega-Casas et al., GCN 38692; Ghosh et al., GCN 38702; An et al., GCN 38704; Volnova et al., GCN 38709; Strobl and Jelinek, GCN 38715) is clearly detected in the stacked image with the brightness of R = 20.97 +/- 0.06. Based on photometry in R filter (this report and photometry by Volnova et al., GCN 38709) we found that the light curve of the afterglow of GRB 241228B/GOTO24jmz can be fitted with a simple power-law model with an power law index of -0.66. The photometry is based on nearby SDSS stars used by Volnova et al., GCN 38709 (magnitudes were converted with Lupton 2005 equations). View this GCN Circular online at https://gcn.nasa.gov/circulars/38733. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36734] GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38732 SUBJECT: GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation DATE: 24/12/30 20:16:39 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex(a)gmail.com> A. Volnova (IKI), A. Pozanenko (IKI), V. Rumyantsev (CrAO), N. Pankov (HSE, IKI) report on behalf of GRB-IKI-FuN collaboration: We observed the GRB 241229B (Fermi GBM Team, GCN 38698; D'Ai et al., GCN 38699) with 2.6-meter ZTSh telescope of CrAO. The observations started on 2024-12-29 (UT) 20:22:02, i.e. ~15.4 hours after GBM trigger. We clearly detected SVOM/VT optical candidate (SVOM/VT team, GCN 38729). The preliminary photometry of the the optical candidate is the following: Date UT start T0+ Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2024-12-29 20:22:02 0.64631 88x120 R 21.91 0.05 24.2 The magnitudes are calibrated using nearby Pan-Starrs PS1 (transformed into R by Lupton's transformations) RA Dec R_Lupton 18:16:50.10 +74:41:42.2 18.928 +- 0.020 18:16:33.99 +74:41:43.6 18.778 +- 0.026 18:16:26.64 +74:41:33.2 17.917 +- 0.014 View this GCN Circular online at https://gcn.nasa.gov/circulars/38732. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36733] GRB 241229A: SAO RAS optical observations
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38731 SUBJECT: GRB 241229A: SAO RAS optical observations DATE: 24/12/30 16:54:52 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova (SAO RAS), A. S. Pozanenko (IKI RAS) report on behalf of the GRB follow-up team. We partially covered the error circle of SVOM/ECLAIRs GRB 241229A (Liang et al., GCN 38697) with the 1-m telescope of SAO RAS, Zeiss-1000 equipped with the CCD-photometer. We obtained 6 x 300 sec. images in Rc band on 2024-12-29T23:40:01--2024-12-30T00:16:47 (t_mid - T0 = 23.9 hours). Within the enhanced XRT position (Williams et al., GCN 38728) of X-ray candidate previously reported by Evans (GCN 38711) and Jiang et al. (GCN 38726, EP-FXT candidate #2) we did not detect any new source down to the limiting magnitude of R_lim = 22.3. We should note the presence of the nearby galaxy J125129.26+314455.4 visible in archive images with the brightness of R2 = 20.39 (USNO-B1) and r = 20.402 +/- 0.043 (SDSS). In our stacked frame we measured the brightness of the galaxy as R = 20.26 +/- 0.05 (diameter of aperture 9".94, calibrated against R2 magnitudes of nearby USNO-B1 stars). The angular distance from EP candidate position to the measured center of the galaxy is 2".5 (corresponding 18 kpc, z_phot = 0.2875, H0 = 72 km/s/Mpc), and 6".7 (47 kpc) from XRT position to the galaxy. View this GCN Circular online at https://gcn.nasa.gov/circulars/38731. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36732] IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38730 SUBJECT: IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube DATE: 24/12/30 16:51:11 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-Cascade 241228A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/140298_78422774.amon) in a time range of 1000 seconds centered on the alert event time (2024-12-28 15:37:06.900 UTC to 2024-12-28 15:53:46.900 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-Cascade 241228A. 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-Cascade 241228A ranges from 1.4e-01 to 1.7e-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 2e+02 GeV and 9e+04 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2024-12-27 15:45:26.900 UTC to 2024-12-29 15:45:26.900 UTC). In this case, we report a p-value of 0.33, 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-Cascade 241228A ranges from 1.6e-01 to 2.1e-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/38730. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36731] GRB 241229B: SVOM/VT optical candidate
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38729 SUBJECT: GRB 241229B: SVOM/VT optical candidate DATE: 24/12/30 16:15:59 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> SVOM/VT commissioning team: Y. L. Qiu, H. L. Li (NAOC), A. Li (BNU), Y. F. Liang (PMOC), L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, Z. H. Yao (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: The SVOM/VT conducted a ToO follow-up observations of the Fermi (GCN 38698) and Swift triggered GRB 241229B (GCN 38699) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously, from 12.09 hours to 15.5 hours after the burst. A new optical source was detected within the errorbox of XRT (GCN 38708) in VT_R stacked image, compared to the PanSTARRS catalog. The brightness of the source was estimated to be 21.8 ± 0.1 mag in AB magnitude in VT_R image at the mid time of 13.8 hours post the burst, with a total exposure time of 34*60 seconds. The source was not detected in VT_B stacked image with 3 sigma upper limit of ~23.2 mag in AB magnitude. The source is located at RA, Dec = 274.1803, 74.6851 deg, which is equivalent to: RA (J2000) : 18:16:43.271 Dec (J2000): +74:41:06.04 with an uncertainty of 0.5 arcsec. We do not confirm the fading of the source, but which might be the candidate for the gamma-ray burst. More deep follow-ups are encouraged for the nature of the source. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/38729. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36730] GRB 241229B: SVOM/VT optical candidate
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38729 SUBJECT: GRB 241229B: SVOM/VT optical candidate DATE: 24/12/30 16:15:59 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> SVOM/VT commissioning team: Y. L. Qiu, H. L. Li (NAOC), A. Li (BNU), Y. F. Liang (PMOC), L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, Z. H. Yao (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: The SVOM/VT conducted a ToO follow-up observations of the Fermi (GCN 38698) and Swift triggered GRB 241229B (GCN 38699) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously, from 12.09 hours to 15.5 hours after the burst. A new optical source was detected within the errorbox of XRT (GCN 38708) in VT_R stacked image, compared to the PanSTARRS catalog. The brightness of the source was estimated to be 21.8 ± 0.1 mag in AB magnitude in VT_R image at the mid time of 13.8 hours post the burst, with a total exposure time of 34*60 seconds. The source was not detected in VT_B stacked image with 3 sigma upper limit of ~23.2 mag in AB magnitude. The source is located at RA, Dec = 274.1803, 74.6851 deg, which is equivalent to: RA (J2000) : 18:16:43.271 Dec (J2000): +74:41:06.04 with an uncertainty of 0.5 arcsec. We do not confirm the fading of the source, but which might be the candidate for the gamma-ray burst. More deep follow-ups are encouraged for the nature of the source. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/38729. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36729] GRB 241229A: Swift-XRT observations
by GCN Circulars 30 Dec '24

30 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38728 SUBJECT: GRB 241229A: Swift-XRT observations DATE: 24/12/30 15:20:30 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M. A. Williams (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected burst GRB 241229A, collecting 1.9 ks of Photon Counting (PC) mode data between T0+65.5 ks and T0+72.9 ks. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. This source is 7.1 arc-seconds from the 2nd source in the list of the afterglow candidates reported by Einstein Probe/FXT (GCN #38726). Details of this source are given below: Source 1: RA (J2000.0): 192.8735 = 12:51:29.63 Dec (J2000.0): +31.7474 = +31:44:50.6 Error: 4.3 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: 0.0172 +/- 0.0038 ct s^-1 Distance: 399 arcsec from SVOM/ECLAIRs position. Flux: (4.32 +/- 0.96)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021751. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38728. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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