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

[vsnet-grb-info 34659] EP240703a: EP-WXT detection of a fast X-ray transient
by GCN Circulars 03 Jul '24

03 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36807 SUBJECT: EP240703a: EP-WXT detection of a fast X-ray transient DATE: 24/07/03 10:00:25 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.L. Wang (NAOC, CAS), C. Y. Dai (NJU), J. Q. Peng, Q. C. Shui (IHEP, CAS), C. C. Jin, Z. X. Ling, W. Yuan, Y. Liu, C. Zhang, H. Q. Cheng, C. Z. Cui, D. W. Fan, H. B. Hu, J. W. Hu, M. H. Huang, D. Y. Li, H. Y. Liu, M. J. Liu, Z. Z. Lv, T. Y. Lian, X. Mao, H. W. Pan, X. Pan, H. Sun, W. X. Wang, Y. L. Wang, S. X. Wen, Q. Y. Wu, X. P. Xu, Y. F. Xu, H. N. Yang, M. Zhang, W. D. Zhang, W. J. Zhang, Z. Zhang, D. H. Zhao (NAOC, CAS), Y. Chen, S. M. Jia, S. N. Zhang (IHEP, CAS), E. Kuulkers, A. Santovincenzo (ESA), P. O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the Einstein Probe team We report on the detection of a fast X-ray transient, designated EP240703a, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The transient started at 2024-07-03T00:38:40 (UTC). The position of the source is R.A. = 273.803 deg, DEC = -9.681 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The corresponding Galactic coordinates are l = 20.174, b = 3.521. The transient lasted for approximately 300 seconds and had a peak absorbed flux of ~5 x 10^-9 erg/s/cm^2 in the 0.5-4 keV band. The average 0.5-4 keV spectrum can be fitted by an absorbed power law with a column density of 1.5(+0.7/-0.6) x 10^22 cm^-2 and a photon index of 2.0(+1.0/-0.9). The derived average unabsorbed 0.5-4 keV flux is 5.9(+8.6/-2.6) x 10^-9 erg/s/cm^2. If the column density is fixed at the Galactic value of 4.5 x 10^21 cm^-2, the derived photon index is 0.4(+/-0.3) and the average unabsorbed 0.5-4 keV flux is 2.5(+0.4/-0.3) x 10^-9 erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. No previously known X-ray sources at a similar flux level are found within the 3 arcmin region around the source position. We have triggered a Swift target of opportunity observation. Further follow-up observations are encouraged to identify the nature of this X-ray transient. The above observation was made with the WXT instrument during the commissioning phase of EP. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES. View this GCN Circular online at https://gcn.nasa.gov/circulars/36807. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34658] EP240703a: EP-WXT detection of a fast X-ray transient
by GCN Circulars 03 Jul '24

03 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36807 SUBJECT: EP240703a: EP-WXT detection of a fast X-ray transient DATE: 24/07/03 10:00:25 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.L. Wang (NAOC, CAS), C. Y. Dai (NJU), J. Q. Peng, Q. C. Shui (IHEP, CAS), C. C. Jin, Z. X. Ling, W. Yuan, Y. Liu, C. Zhang, H. Q. Cheng, C. Z. Cui, D. W. Fan, H. B. Hu, J. W. Hu, M. H. Huang, D. Y. Li, H. Y. Liu, M. J. Liu, Z. Z. Lv, T. Y. Lian, X. Mao, H. W. Pan, X. Pan, H. Sun, W. X. Wang, Y. L. Wang, S. X. Wen, Q. Y. Wu, X. P. Xu, Y. F. Xu, H. N. Yang, M. Zhang, W. D. Zhang, W. J. Zhang, Z. Zhang, D. H. Zhao (NAOC, CAS), Y. Chen, S. M. Jia, S. N. Zhang (IHEP, CAS), E. Kuulkers, A. Santovincenzo (ESA), P. O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the Einstein Probe team We report on the detection of a fast X-ray transient, designated EP240703a, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The transient started at 2024-07-03T00:38:40 (UTC). The position of the source is R.A. = 273.803 deg, DEC = -9.681 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The corresponding Galactic coordinates are l = 20.174, b = 3.521. The transient lasted for approximately 300 seconds and had a peak absorbed flux of ~5 x 10^-9 erg/s/cm^2 in the 0.5-4 keV band. The average 0.5-4 keV spectrum can be fitted by an absorbed power law with a column density of 1.5(+0.7/-0.6) x 10^22 cm^-2 and a photon index of 2.0(+1.0/-0.9). The derived average unabsorbed 0.5-4 keV flux is 5.9(+8.6/-2.6) x 10^-9 erg/s/cm^2. If the column density is fixed at the Galactic value of 4.5 x 10^21 cm^-2, the derived photon index is 0.4(+/-0.3) and the average unabsorbed 0.5-4 keV flux is 2.5(+0.4/-0.3) x 10^-9 erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. No previously known X-ray sources at a similar flux level are found within the 3 arcmin region around the source position. We have triggered a Swift target of opportunity observation. Further follow-up observations are encouraged to identify the nature of this X-ray transient. The above observation was made with the WXT instrument during the commissioning phase of EP. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES. View this GCN Circular online at https://gcn.nasa.gov/circulars/36807. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34657] EP240702a: GSP optical upper limit
by GCN Circulars 03 Jul '24

03 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36806 SUBJECT: EP240702a: GSP optical upper limit DATE: 24/07/03 04:26:38 GMT FROM: Wenxiong Li <liwenxiong1992(a)gmail.com> W. X. Li, S. J. Xue (NAOC), M. Andrews, J. Farrah, D. A. Howell, M. Newsome, E. Padilla Gonzalez, C. McCully, and G. Terreran (Las Cumbres Observatory), on behalf of a larger collaboration, report: Following the detection of the fast X-ray transient EP240702a by the Einstein Probe (Chen et al., GCN 36801), we initiated observations of the fast X-ray transient location starting on July 2 at 6:10 UT (~5 hours after the trigger) in the r band. These observations were conducted using the 1-meter telescope at the Las Cumbres Observatory node located at Cerro Tololo Inter-American Observatory in Chile. No new optical source was detected in the co-added images within the EP/WXT error box down to ~21.5 mag. These observations were taken as part of the Global Supernova Project. View this GCN Circular online at https://gcn.nasa.gov/circulars/36806. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34656] The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
by GCN Circulars 03 Jul '24

03 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36805 SUBJECT: The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A DATE: 24/07/03 03:46:41 GMT FROM: Shaolin Xiong at IHEP <xiongsl(a)ihep.ac.cn> SVOM/GRM team: Yong-Wei Dong, Jiang-Tao Liu, Shi-Jie Zheng, Wen-Jun Tan, Jian-Chao Sun, Chen-Wei Wang, Jiang He, Min Gao, Hao-Xuan Guo, Yue Huang, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Wen-Long Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Patrick Maeght (LUPM), Frédéric Piron (LUPM), Jingwei Wang (IAP) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), JeanLuc Attéia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), 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), Bing Zhang (UNLV) report on behalf of the SVOM team: During the commissioning phase of SVOM which was launched on June 22, 2024 from the Xichang Satellite Launching Center, China, the Gamma-Ray burst Monitor (GRM), as one of the four multi-wavelength telescopes on-board SVOM, detected three long gamma-ray bursts (GRBs), GRB 240627B at 2024-06-27T20:08:11.750 UTC (T0), GRB 240629A at 2024-06-29T16:53:53.000 UTC (T0) and GRB 240702A at 2024-07-02T21:14:50.700 UTC (T0), with on-ground blind search using event-by-event data downloaded through the X-band ground station. The light curves of GRB 240627B were also successfully downloaded through the VHF system with low latency owing to an in-flight trigger just about 50 s after this burst. Although the calibration is ongoing, the preliminary GRM light curves are well consistent with the Fermi/GBM and GECAM-C observations. The automatic in-flight trigger strategy of GRM is under commissioning. The GRB 240627B light curves can be found here: http://www.bursthub.cn//admin/static/svgrb240627B.png The GRB 240629A light curves can be found here: http://www.bursthub.cn//admin/static/svgrb240629A.png The GRB 240702A light curves can be found here: http://www.bursthub.cn//admin/static/svgrb240702A.png We note that these are the first three GRBs detected by SVOM. More GRBs are expected to be detected by SVOM as other instruments are gradually turned on according to the operation plans. 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. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for these bursts is: Shao-Lin Xiong (IHEP)(xiongsl(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/36805. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34655] GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
by GCN Circulars 02 Jul '24

02 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36804 SUBJECT: GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885) DATE: 24/07/02 21:48:32 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger at 21:14:50 on 02 July 2024 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position is: RA(2000.0) = 331.9 deg Decl.(2000.0) = 13.1 deg The 1 sigma statistical error radius is 5.1 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB240702885/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB240702885/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB240702885/json View this GCN Circular online at https://gcn.nasa.gov/circulars/36804. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34654] Fermi GRB 240702A: Global MASTER-Net observations report
by GCN Circulars 02 Jul '24

02 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36803 SUBJECT: Fermi GRB 240702A: Global MASTER-Net observations report DATE: 24/07/02 21:30:44 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240702A ( Fermi GBM team, GCN 36802) errorbox 95 sec after notice time and 127 sec after trigger time at 2024-07-02 21:16:58 UT, with upper limit up to 19.6 mag. The observations began at zenith distance = 61 deg. The sun altitude is -22.7 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240702A errorbox 229 sec after notice time and 261 sec after trigger time at 2024-07-02 21:19:12 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 78 deg. The sun altitude is -69.4 deg. The galactic latitude b = -34 deg., longitude l = 77 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2517761 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 143 | 2024-07-02 21:16:58 | MASTER-Tavrida | (22h 17m 36.31s , +10d 29m 35.2s) | C | 30 | 17.3 | 143 | 2024-07-02 21:16:58 | MASTER-Tavrida | (22h 17m 30.89s , +10d 34m 15.8s) | C | 30 | 16.6 | 186 | 2024-07-02 21:17:41 | MASTER-Tavrida | (22h 17m 42.39s , +10d 28m 32.8s) | C | 30 | 17.3 | 186 | 2024-07-02 21:17:42 | MASTER-Tavrida | (22h 17m 37.01s , +10d 33m 13.7s) | C | 30 | 16.7 | 232 | 2024-07-02 21:18:22 | MASTER-Tavrida | (22h 17m 35.53s , +10d 27m 30.5s) | C | 40 | 17.4 | 232 | 2024-07-02 21:18:23 | MASTER-Tavrida | (22h 17m 30.18s , +10d 32m 11.2s) | C | 40 | 17.0 | 292 | 2024-07-02 21:19:12 | MASTER-SAAO | (22h 14m 58.07s , +04d 53m 32.0s) | C | 60 | 17.5 | 289 | 2024-07-02 21:19:14 | MASTER-Tavrida | (22h 17m 40.91s , +10d 27m 30.2s) | C | 50 | 17.4 | 289 | 2024-07-02 21:19:14 | MASTER-Tavrida | (22h 17m 35.58s , +10d 32m 11.1s) | C | 50 | 17.0 | 360 | 2024-07-02 21:20:15 | MASTER-Tavrida | (22h 17m 38.36s , +10d 28m 57.5s) | C | 70 | 17.7 | 360 | 2024-07-02 21:20:15 | MASTER-Tavrida | (22h 17m 33.08s , +10d 33m 38.0s) | C | 70 | 17.1 | 371 | 2024-07-02 21:20:31 | MASTER-SAAO | (22h 25m 25.30s , +01d 05m 23.1s) | C | 60 | 18.4 | 504 | 2024-07-02 21:21:44 | MASTER-Tavrida | (22h 27m 15.40s , +34d 44m 40.1s) | C | 180 | 19.6 | 504 | 2024-07-02 21:21:44 | MASTER-Tavrida | (22h 27m 10.97s , +34d 49m 11.3s) | C | 180 | 19.5 | 450 | 2024-07-02 21:21:51 | MASTER-SAAO | (22h 22m 56.02s , +04d 52m 39.8s) | C | 60 | 17.6 | 530 | 2024-07-02 21:23:10 | MASTER-SAAO | (22h 33m 18.91s , +01d 05m 39.9s) | C | 60 | 18.6 | 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/36803. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34653] GRB 240702A: Fermi GBM Final Real-time Localization
by GCN Circulars 02 Jul '24

02 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36802 SUBJECT: GRB 240702A: Fermi GBM Final Real-time Localization DATE: 24/07/02 21:25:42 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 SHORT GRB At 21:14:50 UT on 2 Jul 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240702A (trigger 741647695.826936 / 240702885). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 334.5, Dec = 14.9 (J2000 degrees, equivalent to J2000 22h 18m, 14d 54'), with a statistical uncertainty of 18.0 degrees. The angle from the Fermi LAT boresight is 61.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240702885/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240702885/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240702885/… View this GCN Circular online at https://gcn.nasa.gov/circulars/36802. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34652] EP240702a: EP-WXT detection of a fast X-ray transient
by GCN Circulars 02 Jul '24

02 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36801 SUBJECT: EP240702a: EP-WXT detection of a fast X-ray transient DATE: 24/07/02 09:10:43 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> W. Chen (NAOC, CAS), C. Y. Dai (NJU), S. X. Wen, Z. X. Ling, W. Yuan, Y. Liu, C. Zhang, C. C. Jin, H. Q. Cheng, C. Z. Cui, D. W. Fan, H. B. Hu, J. W. Hu, M. H. Huang, D. Y. Li, H. Y. Liu, M. J. Liu, Z. Z. Lv, T. Y. Lian, X. Mao, H. W. Pan, X. Pan, H. Sun, W. X. Wang, Y. L. Wang, Q. Y. Wu, X. P. Xu, Y. F. Xu, H. N. Yang, M. Zhang, W. D. Zhang, W. J. Zhang, Z. Zhang, D. H. Zhao (NAOC, CAS), Y. Chen, S. M. Jia, S. N. Zhang (IHEP, CAS), E. Kuulkers, A. Santovincenzo (ESA), P. O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the Einstein Probe team We report on the detection of a fast X-ray transient, designated EP240702a, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The transient started at 2024-07-02T00:50:05 (UTC) and triggered the WXT on-board processing unit. The position of the source is R.A. = 328.203 deg, DEC = -38.980 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The transient event lasts for approximately 50 seconds and has a peak absorbed flux of ~1.2 x 10^-8 erg/s/cm^2 in the 0.5-4 keV band. The average 0.5-4 keV spectrum can be fitted by an absorbed power law with a photon index of 1.1(+/-0.2) (with the column density fixed at the Galactic value of 2.0 x 10^20 cm^-2). The derived average unabsorbed 0.5-4 keV flux is 5.4(+1.5/-1.2) x 10^-9 erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. No previously known X-ray sources at a similar flux level are found within the 3 arcmin region around the source position. We triggered a Swift target of opportunity observation. Further follow-up observations are encouraged to identify the nature of this X-ray transient. The above observation was made with the WXT instrument during the commissioning phase of EP. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES. View this GCN Circular online at https://gcn.nasa.gov/circulars/36801. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34651] LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
by GCN Circulars 01 Jul '24

01 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36800 SUBJECT: LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO DATE: 24/07/01 21:57:03 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> Samuele Ronchini (PSU), James DeLaunay (PSU), Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT was observing 90% of the GW localization probability ([bayestar.multiorder.fits](https://gracedb.ligo.org/api/superevents/S240627b…) at merger time. A fraction 22% of the GW localization posterior is contained inside the BAT coded FoV. The LVK notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; [Tohuvavohu et al. 2020, ApJ, 900, 1](https://iopscience.iop.org/article/10.3847/1538-4357/aba94f)) Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. Using the NITRATES analysis ([DeLaunay + Tohuvavohu 2022, ApJ, 941, 169](https://iopscience.iop.org/article/10.3847/1538-4357/ac9d38)) we searched for emission on 8 timescales from 0.128s to 16.384s in the interval [-20,+20] seconds around the merger time. We find no evidence for a signal, and derive the following upper limits. We quote the 5-sigma flux upper limits in the 15-350 keV band, weighted over the GW localization, for four spectral templates (soft, normal, and hard GRB-like templates described in [arXiv:1612.02395], and spectral shape from GRB170817A [arXiv:1710.05446]) and for four time bins. In units of 10^-7 erg/s/cm^2: |time_bin (s) | soft|normal| hard | GRB170817 |-|-|-|-|-| |0.256 |17.2 | 11.2 | 9.86 | 12.5 |1.024 |8.78 | 5.70 | 5.03 | 6.40 |4.096 |4.72 | 3.07 | 2.71 | 3.44 |16.384 |2.95 | 1.91 | 1.69 | 2.15 The upper limits as function of sky position are plotted here, alongside the GW localization: [https://doi.org/10.5281/zenodo.12598045]() The solid and dashed lines indicate the 90% and 50% GW contour levels, respectively. The corresponding fits file is also included. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: [https://www.swift.psu.edu/guano/]() View this GCN Circular online at https://gcn.nasa.gov/circulars/36800. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 34650] Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
by GCN Circulars 01 Jul '24

01 Jul '24

TITLE: GCN CIRCULAR NUMBER: 36799 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB DATE: 24/07/01 14:22:08 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> L. Scotton (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 741448122/240630575 at 13:48:37.05 UT on 30 June 2024, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to SAA entry." View this GCN Circular online at https://gcn.nasa.gov/circulars/36799. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0