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

[vsnet-grb-info 33995] IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 18 Apr '24

18 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36152 SUBJECT: IceCube-Cascade 240416A: Upper limits from a search for additional neutrino events in IceCube DATE: 24/04/17 20:47:30 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 240416A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/139293_45286937.amon) in a time range of 1000 seconds centered on the alert event time (2024-04-16 17:02:11.220 UTC to 2024-04-16 17:18:51.220 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 240416A. 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 240416A ranges from 1.3e-01 to 1.4e-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 1e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2024-04-15 17:10:31.220 UTC to 2024-04-17 17:10:31.220 UTC). In this case, we report a p-value of 0.56, 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 240416A ranges from 1.5e-01 to 1.7e-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/36152. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33994] GRB 240417A: Fermi GBM Final Real-time Localization
by GCN Circulars 18 Apr '24

18 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36151 SUBJECT: GRB 240417A: Fermi GBM Final Real-time Localization DATE: 24/04/17 18:56:42 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 18:46:10 UT on 17 Apr 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240417A (trigger 735072375.64676 / 240417782). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 30.7, Dec = -49.7 (J2000 degrees, equivalent to J2000 02h 02m, -49d 42'), with a statistical uncertainty of 12.8 degrees. The angle from the Fermi LAT boresight is 133.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240417782/… View this GCN Circular online at https://gcn.nasa.gov/circulars/36151. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33993] EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa
by GCN Circulars 18 Apr '24

18 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36150 SUBJECT: EP240414a: Pan-STARRS detects re-brightening of the candidate counterpart AT2024gsa DATE: 24/04/17 18:13:16 GMT FROM: S. Srivastav at Oxford <shubhamsrivastav(a)gmail.com> S. Srivastav, J. H. Gillanders, L. Rhodes (Oxford), S. J. Smartt (Oxford/QUB), T.-W. Chen (NCU), M. Huber, K. C. Chambers (IfA), M. Fulton, K. W. Smith (QUB) report on behalf of a larger collaboration: We report optical follow-up observations of AT2024gsa (Aryan et al., GCN 36094; Chen et al. TNS Astronomical Transient Report No. 207843), the candidate optical counterpart to the fast X-ray transient EP240414a (Lian et al., GCN 36091; Guan et al., GCN 36129). AT2024gsa was reported to be decaying in the optical (Xu et al., GCN 36105). We observed AT2024gsa with the 1.8-m Pan-STARRS1 telescope in iz-bands on 2 epochs, with observations starting on MJDs 60416.4 and 60417.4, corresponding to ~2.0 and ~3.0 days post-discovery of the X-ray transient. Our PS1 photometry shows the transient has brightened from 22.2 +/- 0.3 (on MJD 60416.4) to 20.9 +/- 0.06 (on MJD 60417.4) in the i-band, suggesting a rise of ~1.3 mag/day. A similar rise was also seen in the z-band. Assuming AT2024gsa is associated with the potential host galaxy SDSS J124601.99-094309.3 at z=0.41 (Jonker et al., GCN 36110), the transient currently has an absolute rest-frame r-band magnitude of ~ -21. Further followup observations are encouraged. View this GCN Circular online at https://gcn.nasa.gov/circulars/36150. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33992] LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36149 SUBJECT: LIGO/Virgo/KAGRA S240413p: historical ATLAS and ZTF observations of the candidate AGN counterpart DATE: 24/04/17 15:52:16 GMT FROM: Lauren Rhodes at Oxford <lauren.rhodes(a)physics.ox.ac.uk> L. Rhodes (Oxford), S. J. Smartt (Oxford/QUB), J. H. Gillanders, S. Srivastav, A. Cooper (Oxford), M. Fulton, K. W. Smith (QUB) and T.-W. Chen (NCU) report on behalf of a larger collaboration: C. R. Bom et al (GCN 36146) report a candidate optical counterpart associated with a known AGN for the binary black hole merger S240413p, as reported by LVK (GCN 36075). Here we note the proposed AGN counterpart (WISEAJ105115.40-2B054824.6; Veron-Cetty & Veron, 2006, A&A 455, 733) for S240313p has been exhibiting continued AGN flaring activity since ~January 2021, as detected by the survey telescopes ATLAS and ZTF. The publicly available Lasair lightcurve illustrates this long-lived behaviour in the ZTF data (https://lasair-ztf.lsst.ac.uk/objects/ZTF19aaflhnr). ATLAS data are available through the forced photometry server (https://fallingstar.com) and also show similar elevated activity over the last ~150 days. Based on the most recent observations, we see no evidence for additional flaring activity, after the merger time of S240313p, which is above its previously observed behaviour across the last ~3 years. Thus, it seems unlikely that S240313p has produced a detectable flare within this AGN. The excess flux Bom et al (GCN 36146) observe is certainly real, but the apparent flaring can be attributed to the large time difference between their recent observation and the template image from Pan-STARRS (Pan-STARRS1 3Pi survey: Chambers et al. 2016arXiv161205560C) which is made from a stack of images taken from 2009-2014. View this GCN Circular online at https://gcn.nasa.gov/circulars/36149. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33991] GRB 240415A: Glowbug gamma-ray detection
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36148 SUBJECT: GRB 240415A: Glowbug gamma-ray detection DATE: 24/04/17 14:55:09 GMT FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil> C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (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 240415A, which was also detected by Fermi/GBM (GCN 36107, 36134) and Swift/BAT (GCN 36108, 36143). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-04-15 06:26:52.488 with a duration of 8.2 s and a total significance of about 17.7 sigma. The light curve comprises two primary peaks at ~T0+1s and ~T0+4s. 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/36148. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33990] GRB 240414A: Glowbug gamma-ray detection
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36147 SUBJECT: GRB 240414A: Glowbug gamma-ray detection DATE: 24/04/17 14:54:25 GMT FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil> C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (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 240414A, which was also detected by Swift/BAT (GCN 36083, 36140) and Fermi/GBM (GCN 36120). The detection occurred during a time of high background, thus complicating the analysis. Using an adaptive window with a resolution of 32-ms, the primary peak was recovered, with a burst onset determined to be 2024-04-14 02:20:36.904 with a duration of 4.1 s and a total significance of about 9.7 sigma. Lower-level emission is observed up to ~T0+30s. 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/36147. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33989] LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36146 SUBJECT: LIGO/Virgo/KAGRA S240413p: STEP - T80S Search and Candidate Counterpart Identification DATE: 24/04/17 14:16:10 GMT FROM: Clecio Bom at CBPF <debom(a)cbpf.br> C.R.Bom (CBPF), A. Santos (CBPF), C. D. Kilpatrick (Northwestern), Luidhy Santana-Silva (CBPF), Phelipe Darc (CBPF), Claudia Mendes de Oliveira (IAG-USP) report on behalf of the STEP-GW collaboration: We conducted an optical search for candidate counterparts in the localization region of LVK gravitational wave event S240413p with the T80S 0.8-m robotic telescope using the 1.4 x 1.4 field-of-view T80S-Cam imager. The tiling was optimally determined using the latest localization map from the LVK and galaxy catalogs in Teglon (Coulter et al., in prep.). In total, T80S observed 28 fields within the 90th percentile localization region of S240413p. We subtracted Pan-STARRS template images from the T80S images using photpipe (Rest et al., 2005). As this GW event is classified as a binary black hole merger (GCN #36075), we also cross-matched with known AGNs. we identified the following candidate counterpart in our imaging: Name MJD RA(deg) Dec(deg) Filter Mag Magerr STEP24a 60416.109690 162.814 5.806 10:51:15.43 +05:48:24.69 g 18.626 0.046 This candidate shows a possible flare and has a spectroscopic redshift of 0.069, which falls close to the lower end of the 2-sigma distance distribution of S240413p. We have checked the Minor Planet Center and Transient Name Server, finding no previously reported solar system object or transient. We encourage follow-up observations of this source. View this GCN Circular online at https://gcn.nasa.gov/circulars/36146. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33988] GRB 240415B: GECAM-B detection
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36145 SUBJECT: GRB 240415B: GECAM-B detection DATE: 24/04/17 09:39:18 GMT FROM: xiesl(a)mails.ccnu.edu.cn Sheng-Lun Xie, Shao-Lin Xiong report on behalf of the GECAM team: GECAM-B was triggered in-flight and on-ground by a short burst, GRB 240415B, at 2024-04-15T03:10:49.150 UTC (T0), which was also observed by Swift/BAT (GCN #36125). According to the GECAM-B light curve, this burst consists of roughly a pulse with a total duration of ~250 ms. The GECAM-B ground calculated location (J2000) is: Ra: 156.77 deg Dec: -20.78 deg Err: 11.16 deg (1-sigma, statistical only) This GECAM-B localization is consistent with that of Swift/BAT within the error. We note that these results are very preliminary. Refined analysis will be reported later. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/36145. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33987] EP 240416a: Xinglong and NOT decaying optical counterpart
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36144 SUBJECT: EP 240416a: Xinglong and NOT decaying optical counterpart DATE: 24/04/17 07:45:53 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> J. An, X. Liu, S.Q. Jiang, Z.P. Zhu, J. Zheng, S. Liu, J.J. Jin, S.Y. Fu, T.H. Lu, Z. Fan, D. Xu (NAOC), J.P.U. Fynbo (DAWN/NBI) report on behalf of a large collaboration: We observed the field of the X-ray transient, EP 240416a, detected by EP/WXT (Cheng et al., GCN 36138) using the 2.16-m telescope located at Xinglong, Hebei, China. We obtained 5 x 360 s R-band frames with a median time of 2024-04-16T17:18:06, i.e., 14.6 hr after the EP trigger. The stacked R-band image has a limiting magnitude of R ~ 22 mag, calibrated with the PanSTAR field. Inspection of the whole EP/WXT 3 arcmin error circle produces a few low S/N optical counterpart candidates. We subsequently performed r-band photometry at the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera, and obtained 3 x 300 s frames in the Sloan r-band with a median time of 2024-04-17T01:00:00, i.e., 22.3 hr after the EP trigger. The stacked r-band image has a limiting magnitude of r ~ 23.5 mag, calibrated with the PanSTAR field. Inspection of the whole EP/WXT 3 arcmin error circle also produces a few optical counterpart candidates. The candidates from the two epochs are corssmatched in position and only one single optical transient (OT) is left. It is localized at R.A. = 13:32:34.51 (J2000) Dec. = -13:37:48.88 (J2000) with an uncertainty of radius ~ 0.3 arcsec, being consistent with the candidate reported by Kinder (Chen et al., GCN 36139). This OT has m(R) = 21.8 +/- 0.4 (Vega) in the Xinglong image and decayed to m(r) = 22.66 +/- 0.18 (AB) in the NOT image, calibrated with the PanSTARRS field. The decay rate is consistent with that for typical GRB optical afterglows. Therefore, we suggest that the OT is very likely the optical counterpart of EP 240416a, which is likely a GRB event. View this GCN Circular online at https://gcn.nasa.gov/circulars/36144. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 33986] GRB 240415A: Swift-BAT refined analysis
by GCN Circulars 17 Apr '24

17 Apr '24

TITLE: GCN CIRCULAR NUMBER: 36143 SUBJECT: GRB 240415A: Swift-BAT refined analysis DATE: 24/04/17 02:09:31 GMT FROM: Mike Moss at NASA GSFC <mikejmoss3(a)gmail.com> M. J. Moss (GSFC), S. D. Barthelmy (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), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240415A (trigger #1221874) (Moss, et al., GCN Circ. 36108). The BAT ground-calculated position is RA, Dec = 129.197, 73.150 deg which is RA(J2000) = 08h 36m 47.2s Dec(J2000) = +73d 09' 01.7" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve displays a bright pulse lasting for ~15 s and peaking at ~T0+5 s and another dim pulse of emission at ~T0+30 s. The T90 (15-350 keV) is 30.96 +- 3.59 sec (estimated error including systematics). The time-averaged spectrum from T-0.70 to T+37.50 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.28 +- 0.13. The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+5.09 sec in the 15-150 keV band is 4.6 +- 0.4 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/1221874 View this GCN Circular online at https://gcn.nasa.gov/circulars/36143. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0