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

[vsnet-grb-info 32639] GRB 230930A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Oct '23

01 Oct '23

TITLE: GCN CIRCULAR NUMBER: 34784 SUBJECT: GRB 230930A: Fermi GBM Final Real-time Localization DATE: 23/09/30 22:11:01 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 22:00:25 UT on 30 Sep 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230930A (trigger 717804030.135796 / 230930917). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 105.6, Dec = -9.2 (J2000 degrees, equivalent to J2000 07h 02m, -9d 11'), with a statistical uncertainty of 6.8 degrees. The angle from the Fermi LAT boresight is 70.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230930917/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230930917/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230930917/… View this GCN Circular online at https://gcn.nasa.gov/circulars/34784. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32638] LIGO/Virgo/KAGRA S230930al: Identification of a GW compact binary merger candidate
by GCN Circulars 30 Sep '23

30 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34783 SUBJECT: LIGO/Virgo/KAGRA S230930al: Identification of a GW compact binary merger candidate DATE: 23/09/30 14:37:20 GMT FROM: Ulyana Dupletsa <ulyana.dupletsa(a)gssi.it> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S230930al during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2023-09-30 11:07:30.411 UTC (GPS time: 1380107268.411). The candidate was found by the CWB [1], GstLAL [2], MBTA [3], and PyCBC Live [4] analysis pipelines. S230930al is an event of interest because its false alarm rate, as estimated by the online analysis, is 7.4e-09 Hz, or about one in 4 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S230930al The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), 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%. [5] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [5] 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%. 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 [6], distributed via GCN notice about 23 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [6], 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 2799 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5123 +/- 1615 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] Chatterjee et al. ApJ 896, 54 (2020) [6] Singer & Price PRD 93, 024013 (2016) View this GCN Circular online at https://gcn.nasa.gov/circulars/34783. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32637] NuEm-230927A: Swift-XRT follow-up
by GCN Circulars 29 Sep '23

29 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34782 SUBJECT: NuEm-230927A: Swift-XRT follow-up DATE: 23/09/29 21:20:17 GMT FROM: Hugo Ayala at Pennsylvania State University <hgayala(a)psu.edu> The AMON group reports: We requested follow-up time for the AMON alert NuEM230927A (GCN 34776). The follow-up looks for any x-ray source inside the 90% region of the AMON alert: RA (J2000): 331.92 deg Dec (J2000): 12.44 deg Location uncertainty (90% containment): 0.24 deg (statistical only). We used the available software in www.swift.ac.uk Swift-XRT started the follow up on 2023-09-28 08:08:01 and ended on 2023-09-28 11:32:27. It collected 3735 sec of photon counting (PC) mode data. One uncatalogued X-ray source has been detected: Source : RA (J2000.0): 331.877 = 22:07:30.50 Dec (J2000.0): 12.357 = +12:21:24 Error: 4.9 arcsec (radius, 90% conf.) Count-rate: (3.7 (+2.1, -1.7))e-3 ct s^-1 The results can be found in: https://www.swift.ac.uk/user_objects/tprods/USERPROD_114407/index.php Source detection is based on Evans, et al. 2020 ApJ Supplemental, 247 AMON seeks to perform a real-time correlation analysis of the high-energy signals across all known astronomical messengers. More information about AMON can be found in https://www.amon.psu.edu/ Information on the IceCube collaboration: http://icecube.wisc.edu/ Information on the HAWC collaboration: https://www.hawc-observatory.org View this GCN Circular online at https://gcn.nasa.gov/circulars/34782. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32636] LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
by GCN Circulars 29 Sep '23

29 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34781 SUBJECT: LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate DATE: 23/09/28 22:55:16 GMT FROM: sushant.sharma-chaudhary(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S230928cb during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2023-09-28 21:58:27.132 UTC (GPS time: 1379973525.132). The candidate was found by the CWB [1], GstLAL [2], MBTA [3], PyCBC Live [4], and SPIIR [5] analysis pipelines. S230928cb is an event of interest because its false alarm rate, as estimated by the online analysis, is 9.5e-10 Hz, or about one in 33 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S230928cb The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), or NSBH (<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%. 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 [7], distributed via GCN notice about 26 seconds after the candidate event time. * bayestar.multiorder.fits,1, 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,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 3093 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5604 +/- 1692 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) View this GCN Circular online at https://gcn.nasa.gov/circulars/34781. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32635] AT2023sva / GRB230916B: GIT observations of the afterglow
by GCN Circulars 28 Sep '23

28 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34780 SUBJECT: AT2023sva / GRB230916B: GIT observations of the afterglow DATE: 23/09/28 18:27:31 GMT FROM: Varun Bhalerao at IIT Bombay <varunb(a)iitb.ac.in> A. Salgundi, V. Swain, R. Kumar, G. Waratkar, R. Sharma, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed AT2023sva (Vail et al., GCN 34730; Tonry et al. 2023, TNS report 188327) which is confirmed as an orphan afterglow (Roberts et al., GCN Circ. 34748; GCN Circ. 34749) with the 0.7m GROWTH-India Telescope (GIT). The observations started at 16:42:17 UT on 2023-09-19, roughly 2.3 days after the first ZTF report. We obtained 10 images of 300s exposure in the r' filter. We clearly detect the candidate in our stacked image at the position reported by Vail et al., GCN Circ. 34730. It was not detected in deep observations on later days. The photometry of the candidate is reported below. ---------------------------------------------------------------- | JD (mid) | Filter | Total Exposure (s) | Magnitude (AB) | Limiting Mag (AB) | | ----------------- | ------ | ------------------ | -------------- | ----------------- | | 2460207.214532005 | r' | 10x300 | 21.89 +/- 0.07 | 22.63 | | 2460209.289487210 | r' | 14x300 | -- | 22.28 | | 2460210.459151377 | r' | 14x300 | -- | 22.36 | ---------------------------------------------------------------- The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. Based on the publicly avialable photometry (Vail et al., GCN Circ. 34730; Malesani et al., GCN Circ. 34731; Parra-Ramos et al., GCN Circ. 34744) and our measurements, we find that the source is consistently fading as a power-law with flux proportional to (t−t0)^−alpha where t0 is MJD 60203.08 +/- 0.25 (2023-09-16 01:55:12) and alpha = 3.79 +/- 0.48. This decline is much faster than typical afterglows. This t0 is consistent with Fermi GBM trigger 716527670/230916144, which is also spatially coincident with the afterglow as reported by Roberts et al. (GCN 34748). The t0 fit confirms the association between the two events, which we name GRB 230916B. The t0 is not consistent with GRB 230916A (Grefenstette et al., GCN 34721). We note that Ruffini et al (GCN 34779) also are referring to this GRB rather than the NuSTAR-reported trigger. Further imaging of the field is encouraged to find any potential host galaxy. The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/. View this GCN Circular online at https://gcn.nasa.gov/circulars/34780. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32634] transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
by GCN Circulars 28 Sep '23

28 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34779 SUBJECT: transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova DATE: 23/09/28 16:05:44 GMT FROM: Remo Ruffini at ICRA <ruffini(a)icra.it> R. Ruffini, Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, N. Sahakyan, Y. Wang, S.S. Xue, S.R. Zhang, on behalf of the ICRANet team, report: Following the BdHN classification [Aimuratov, et al., ApJ 955 (2023) 93] and the determination of the redshift z=2.2 of transient AT2023sva (de Ugarte Postigo, et al., GCN 34740), from the energetics evaluated by Liang Li (2023) from Fermi GBM data in (2.15+/-0.13)x10^{52} erg (see attached figure), we conclude that the source is a BdHN II (GRB230916A). We Propose to look with the James Webb Space Telescope the appearance of the associated supernova (SN) on October 31 (+/-1 day), in order to extend the GRB-SN connection in the range 1<z<3 and verify the standard candle nature of SNe Ib/c. Figure: http://www.icranet.org/documents/GRB230916A.pdf View this GCN Circular online at https://gcn.nasa.gov/circulars/34779. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32633] LIGO/Virgo/KAGRA S230927be: Updated Sky localization
by GCN Circulars 28 Sep '23

28 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34778 SUBJECT: LIGO/Virgo/KAGRA S230927be: Updated Sky localization DATE: 23/09/28 03:53:54 GMT FROM: Colm Talbot at University of Chicago <talbotcolm(a)gmail.com> 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 S230927be (GCN Circular 34775). 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/S230927be For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 298 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1059 +/- 289 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) View this GCN Circular online at https://gcn.nasa.gov/circulars/34778. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32632] LIGO/Virgo/KAGRA S230927l: Updated Sky localization
by GCN Circulars 28 Sep '23

28 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34777 SUBJECT: LIGO/Virgo/KAGRA S230927l: Updated Sky localization DATE: 23/09/28 03:50:19 GMT FROM: Colm Talbot at University of Chicago <talbotcolm(a)gmail.com> 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 S230927l (GCN Circular 34773). 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/S230927l For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 1177 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2966 +/- 1041 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) View this GCN Circular online at https://gcn.nasa.gov/circulars/34777. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32631] AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230927A
by GCN Circulars 27 Sep '23

27 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34776 SUBJECT: AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-230927A DATE: 23/09/27 17:56:35 GMT FROM: Hugo Ayala at Pennsylvania State University <hgayala(a)psu.edu> The AMON, IceCube, and HAWC collaborations report: The AMON NuEm stream channel found a coincidence alert from the IceCube online neutrino selection + HAWC daily monitoring analysis. The analysis looks for IceCube neutrino events -mostly atmospheric in origin- around the position and transit time of a HAWC cluster of likely gamma rays, as identified in the integrated observations from a single transit, in this case having a duration of 6.06 hours. The HAWC transit interval starts from 2023/09/27 01:10:10 UT to 2023/09/27 07:20:17 UT (End of the HAWC transit time) The location of the coincidence is reported as RA (J2000): 331.92 deg Dec (J2000): 12.44 deg Location uncertainty (50% containment): 0.13 deg (statistical only). Location uncertainty (90% containment): 0.24 deg (statistical only). The false alarm rate (FAR) of this coincidence is 3.9 per year. We encourage follow-up observations of the alert region contingent on the availability of resources and interest, given the quoted FAR. AMON seeks to perform a real-time correlation analysis of the high-energy signals across all known astronomical messengers. More information about AMON can be found in https://www.amon.psu.edu/ Information on the IceCube collaboration: http://icecube.wisc.edu/ Information on the HAWC collaboration: https://www.hawc-observatory.org View this GCN Circular online at https://gcn.nasa.gov/circulars/34776. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 32630] LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
by GCN Circulars 27 Sep '23

27 Sep '23

TITLE: GCN CIRCULAR NUMBER: 34775 SUBJECT: LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate DATE: 23/09/27 16:18:47 GMT FROM: brina.martinez(a)ligo.org The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S230927be during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2023-09-27 15:38:32.919 UTC (GPS time: 1379864330.919). The candidate was found by the CWB [1], GstLAL [2], MBTA [3], PyCBC Live [4], and SPIIR [5] analysis pipelines. S230927be is an event of interest because its false alarm rate, as estimated by the online analysis, is 3.2e-10 Hz, or about one in 1e2 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S230927be The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), or NSBH (<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%. 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 [7], distributed via GCN notice about 35 seconds after the candidate event time. * bayestar.multiorder.fits,1, 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,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 527 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1056 +/- 308 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) View this GCN Circular online at https://gcn.nasa.gov/circulars/34775. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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