February 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37186] LIGO/Virgo/KAGRA S250206dm: Updated NED Galaxies in the Localization Volume
by GCN Circulars 07 Feb '25

07 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39177 SUBJECT: LIGO/Virgo/KAGRA S250206dm: Updated NED Galaxies in the Localization Volume DATE: 25/02/07 00:00:46 GMT FROM: David Cook at Caltech/IPAC-NED <dcook(a)ipac.caltech.edu> David O. Cook (Caltech/IPAC), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), Joseph M. Mazzarella (Caltech/IPAC), Marion Schmitz (Caltech/IPAC), and Leo Singer (NASA/GSFC) On behalf of the NASA/IPAC Extragalactic Database (NED) Team. We spatially cross-matched the LVK S250206dm-4-Update sky localization with the NED Local Volume Sample (NED-LVS; Cook et al. 2023), which is a subset of NED with a redshift or redshift-independent distance less than 1000 Mpc. We find 54256 galaxies within the 90% containment volume, and we list here the top 20 galaxies sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full or top 20 list of galaxies in the 90% volume go either to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/ or click on the following links: Full List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250206dm/4 Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250206dm/4/20 The NED-GWF service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic follow-up observations. The NED top 20 list is sorted by the joint probability of the 3D localization and the WISE W1 luminosity, but users can sort on additional pre-computed prioritization metrics (star formation rate, P_3D * P_SFR; and specific star formation rate, P_3D * P_sSFR; etc.) which are available via downloading the entire galaxy list inside the event's probability volume. | objname| ra| dec|objtype| DistMpc|DistMpc_unc| m_NUV| m_NUV_unc| m_Ks| m_Ks_unc| m_W1| m_W1_unc| P_3D|P_3D_LumW1| |-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------| | MCG -01-57-002| 335.01662| -3.45381| G| 254.69| 0.65| null| null| null| null| 9.016| 0.006|2.10e-07| 6.30e-11| |WISEA J035607.76+573251.4| 59.03242| 57.54769| G| 410.56| null| null| null| 12.680| 0.123| 8.610| 0.006|3.52e-08| 4.62e-11| |WISEA J022843.33+542030.5| 37.18021| 54.34178| G| 408.50| null| null| null| 13.098| 0.150| 9.250| 0.006|6.32e-08| 4.06e-11| |WISEA J220219.95-113906.3| 330.58317| -11.65222| G| 302.43| null| 20.465| 0.149| 13.630| 0.229| 9.627| 0.006|1.51e-07| 3.61e-11| |WISEA J003646.96+403047.2| 9.19542| 40.51314| G| 463.14| 0.24| 20.697| 0.096| 13.700| 0.155| 9.758| 0.006|6.85e-08| 3.42e-11| |WISEA J235047.55+293551.6| 357.69817| 29.59772| G| 490.87| null| null| null| 12.766| 0.116| 9.929| 0.006|6.47e-08| 3.10e-11| |WISEA J000430.95+335502.6| 1.12883| 33.91731| G| 495.19| null| null| null| 13.425| 0.157| 9.831| 0.006|5.74e-08| 3.06e-11| | 3C 445| 335.95638| -2.10357| G| 250.91| 0.79| null| null| null| null| 9.765| 0.006|2.10e-07| 3.06e-11| |WISEA J022200.27+503737.1| 35.50117| 50.62697| G| 288.27| null| null| null| 12.566| 0.105| 9.223| 0.006|8.41e-08| 2.84e-11| |WISEA J000012.55+315927.2| 0.05233| 31.99092| G| 358.08| null| null| null| 13.272| 0.144| 10.098| 0.006|1.26e-07| 2.73e-11| |WISEA J001948.39+350244.8| 4.95154| 35.04578| G| 307.16| null| 19.804| 0.052| 12.767| 0.111| 9.747| 0.006|1.20e-07| 2.67e-11| |WISEA J000233.49+320338.6| 0.63946| 32.06067| G| 326.97| null| null| null| 13.158| 0.136| 9.964| 0.006|1.28e-07| 2.64e-11| |WISEA J215400.16-151308.9| 328.50075| -15.21903| G| 293.47| 1.21| 19.446| 0.077| 14.041| 0.269| 9.703| 0.006|1.23e-07| 2.58e-11| |WISEA J231640.26+192021.7| 349.16775| 19.33933| G| 508.89| null| null| null| 13.170| 0.139| 9.560| 0.006|3.49e-08| 2.53e-11| |WISEA J091707.96+104002.7| 139.28314| 10.66755| G| 245.27| 0.07| null| null| null| null| 9.503| 0.006|1.35e-07| 2.38e-11| |WISEA J222725.55-010758.9| 336.85677| -1.13309| G| 270.87| 0.06| 19.196| 0.022| null| null| 10.431| 0.006|2.27e-07| 2.08e-11| | UGC 12801| 357.61283| 26.14639| G| 293.42| 0.39| null| null| 10.743| 0.077| 9.562| 0.006|8.65e-08| 2.07e-11| |WISEA J002726.11+330928.2| 6.85896| 33.15783| G| 389.91| null| null| null| 13.572| 0.166| 8.826| 0.005|2.46e-08| 2.05e-11| |WISEA J045737.46+531524.9| 74.40617| 53.25697| G| 281.45| null| null| null| 12.147| 0.102| 9.130| 0.006|5.54e-08| 2.03e-11| |WISEA J015907.34+514849.0| 29.78058| 51.81344| G| 317.14| null| null| null| 13.443| 0.166| 9.943| 0.006|9.91e-08| 2.01e-11| Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S250206dm sorted by the joint probability of 3D position and WISE W1 luminosity (P_3D * P_LumW1). Galaxy is the NED preferred name. RA and Dec are the Equatorial coordinates in degrees (J2000). Objtype is the object type of the galaxy candidate. Distance is the distance to the galaxy in Mpc. m_NUV and mErr_NUV are the apparent magnitude and error from GALEX. m_Ks and mErr_Ks are the apparent magnitude and error from 2MASS. m_W1 and mErr_W1 are the apparent magnitude and error from AllWISE. P_3D is the probability that the galaxy is in the volume given the distance of GW event. P_3D_LumW1 is the joint probability within the volume weighted by the WISE1 luminosity of the galaxy (P_3D * P_LumW1). View this GCN Circular online at https://gcn.nasa.gov/circulars/39177. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37185] LIGO/Virgo/KAGRA S250206dm: Two counterpart neutrino candidates from IceCube neutrino searches
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39176 SUBJECT: LIGO/Virgo/KAGRA S250206dm: Two counterpart neutrino candidates from IceCube neutrino searches DATE: 25/02/06 22:36:52 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu> IceCube Collaboration (http://icecube.wisc.edu/) reports: Searches for track-like muon neutrino events detected by IceCube consistent with the sky localization of gravitational-wave candidate S250206dm in a time range of 1000 seconds centered on the alert event time (2025-02-06 21:17:10.436 UTC to 2025-02-06 21:33:50.436 UTC) have been performed [1,2]. During this time period IceCube was collecting good quality data. Two hypothesis tests were conducted. The first search is a maximum likelihood analysis which searches for a generic point-like neutrino source coincident with the given GW skymap. The second uses a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the significance estimate [3]. Two track-like events are found in spatial and temporal coincidence with the gravitational-wave candidate S250206dm calculated from the map circulated in the 3-Initial notice. This represents an overall p-value of 0.008 from the generic transient search and an overall p-value of 0.011 for the Bayesian search. These p-values measure the consistency of the observed track-like events with the known atmospheric backgrounds for this single map (not trials corrected for multiple GW events). The most probable multi-messenger source direction based on the neutrinos and GW skymap is RA 149.15 degrees, Dec -17.90 degrees. The two reported p-values can differ due to the estimated distance of the GW candidate. The distance is used as a prior in the Bayesian binary merger search, while it is not taken into account in the generic transient point-like source search. The false alarm rate of these coincidences can be obtained by multiplying the p-values with their corresponding GW trigger rates. Further details are available at https://gcn.nasa.gov/missions/icecube. Properties of the coincident events are shown below. We encourage follow-up observations of both locations. dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(generic transient) p-value(Bayesian) ----------------------------------------------------------------------------------------------------- 289.12 149.16 -17.94 0.43 0.008 0.032 -109.85 354.59 32.79 1.42 0.222 0.018 where: dt = Time of track event minus time of GW trigger (sec) Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event from each search. 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] M. G. Aartsen et al 2020 ApJL 898 L10 [2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80 [3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017 View this GCN Circular online at https://gcn.nasa.gov/circulars/39176. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37184] LIGO/Virgo/KAGRA S250206dm: Identification of a GW compact binary merger candidate
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39175 SUBJECT: LIGO/Virgo/KAGRA S250206dm: Identification of a GW compact binary merger candidate DATE: 25/02/06 22:00:22 GMT FROM: youru.lee(a)g.ncu.edu.tw The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S250206dm during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2025-02-06 21:25:30.439 UTC (GPS time: 1422912348.439). The candidate was found by the GstLAL [1], MBTA [2], and PyCBC Live [3] analysis pipelines. S250206dm is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.3e-09 Hz, or about one in 25 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S250206dm The classification of the GW signal, in order of descending probability, is NSBH (55%), BNS (37%), Terrestrial (8%), or BBH (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is >99%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is 30%. [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 62%. 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 1544 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 409 +/- 139 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 [3] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [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/39175. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37183] LIGO/Virgo/KAGRA S250206dm: NED Galaxies in the Localization Volume
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39174 SUBJECT: LIGO/Virgo/KAGRA S250206dm: NED Galaxies in the Localization Volume DATE: 25/02/06 21:55:45 GMT FROM: David Cook at Caltech/IPAC-NED <dcook(a)ipac.caltech.edu> David O. Cook (Caltech/IPAC), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), Joseph M. Mazzarella (Caltech/IPAC), Marion Schmitz (Caltech/IPAC), and Leo Singer (NASA/GSFC) On behalf of the NASA/IPAC Extragalactic Database (NED) Team. We spatially cross-matched the LVK S250206dm-3-Initial sky localization with the NED Local Volume Sample (NED-LVS; Cook et al. 2023), which is a subset of NED with a redshift or redshift-independent distance less than 1000 Mpc. We find 52020 galaxies within the 90% containment volume, and we list here the top 20 galaxies sorted by the joint probability of the 3D localization and the WISE W1 luminosity (an observable proxy for stellar mass). For the full or top 20 list of galaxies in the 90% volume go either to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/ or click on the following links: Full List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250206dm/3 Top 20 List Download: https://ned.ipac.caltech.edu/uri/NED::GWFglist/fits/S250206dm/3/20 The NED-GWF service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic follow-up observations. The NED top 20 list is sorted by the joint probability of the 3D localization and the WISE W1 luminosity, but users can sort on additional pre-computed prioritization metrics (star formation rate, P_3D * P_SFR; and specific star formation rate, P_3D * P_sSFR; etc.) which are available via downloading the entire galaxy list inside the event's probability volume. | objname| ra| dec|objtype| DistMpc|DistMpc_unc| m_NUV| m_NUV_unc| m_Ks| m_Ks_unc| m_W1| m_W1_unc| P_3D|P_3D_LumW1| |-------------------------|--------------|--------------|-------|-----------|-----------|------------|------------|------------|------------|------------|------------|--------|----------| |WISEA J035607.76+573251.4| 59.03242| 57.54769| G| 410.56| null| null| null| 12.680| 0.123| 8.610| 0.006|5.19e-08| 6.11e-11| |WISEA J022843.33+542030.5| 37.18021| 54.34178| G| 408.50| null| null| null| 13.098| 0.150| 9.250| 0.006|9.06e-08| 5.22e-11| | MCG -01-57-002| 335.01662| -3.45381| G| 254.69| 0.65| null| null| null| null| 9.016| 0.006|1.75e-07| 4.70e-11| |WISEA J220219.95-113906.3| 330.58317| -11.65222| G| 302.43| null| 20.465| 0.149| 13.630| 0.229| 9.627| 0.006|1.87e-07| 4.02e-11| |WISEA J231640.26+192021.7| 349.16775| 19.33933| G| 508.89| null| null| null| 13.170| 0.139| 9.560| 0.006|5.70e-08| 3.72e-11| |WISEA J003646.96+403047.2| 9.19542| 40.51314| G| 463.14| 0.24| 20.697| 0.096| 13.700| 0.155| 9.758| 0.006|7.37e-08| 3.31e-11| |WISEA J215400.16-151308.9| 328.50075| -15.21903| G| 293.47| 1.21| 19.446| 0.077| 14.041| 0.269| 9.703| 0.006|1.64e-07| 3.10e-11| |WISEA J000430.95+335502.6| 1.12883| 33.91731| G| 495.19| null| null| null| 13.425| 0.157| 9.831| 0.006|6.26e-08| 3.00e-11| |WISEA J091707.96+104002.7| 139.28314| 10.66755| G| 245.27| 0.07| null| null| null| null| 9.503| 0.006|1.80e-07| 2.84e-11| |WISEA J235047.55+293551.6| 357.69817| 29.59772| G| 490.87| null| null| null| 12.766| 0.116| 9.929| 0.006|6.50e-08| 2.79e-11| |WISEA J090906.84+134338.0| 137.27863| 13.72719| G| 246.54| 0.03| 19.109| 0.048| null| null| 9.635| 0.006|1.91e-07| 2.71e-11| |WISEA J023348.85+553955.6| 38.45375| 55.66506| G| 554.10| null| null| null| 13.376| 0.194| 8.753| 0.005|1.44e-08| 2.47e-11| |WISEA J213220.13-230609.5| 323.08396| -23.10275| G| 152.92| 0.65| 20.276| 0.135| 12.046| 0.022| 9.287| 0.006|3.19e-07| 2.39e-11| | 3C 445| 335.95638| -2.10357| G| 250.91| 0.79| null| null| null| null| 9.765| 0.006|1.61e-07| 2.11e-11| | 2MFGC 07267| 140.43463| 7.28237| G| 239.49| null| null| null| 12.026| 0.087| 9.803| 0.006|1.77e-07| 2.03e-11| |WISEA J103204.15-302813.3| 158.01758| -30.47050| G| 526.75| 0.65| null| null| 12.749| 0.140| 9.417| 0.005|2.55e-08| 2.03e-11| |WISEA J111625.30-474423.2| 169.10533| -47.74000| G| 541.68| null| null| null| 13.677| 0.237| 9.277| 0.006|2.05e-08| 1.97e-11| |WISEA J004546.18+394932.4| 11.44258| 39.82569| G| 605.36| 0.24| 20.160| 0.035| 13.845| 0.185| 9.381| 0.005|1.82e-08| 1.97e-11| |WISEA J153057.77-694546.5| 232.74150| -69.76292| G| 373.52| null| null| null| 13.645| 0.271| 9.044| 0.006|3.31e-08| 1.87e-11| |WISEA J034501.09+571427.1| 56.25442| 57.24086| G| 395.20| null| null| null| 12.710| 0.124| 10.274| 0.007|7.34e-08| 1.75e-11| Table 1: Top 20 galaxies in NED-LVS that fall in the 90% probability volume for S250206dm sorted by the joint probability of 3D position and WISE W1 luminosity (P_3D * P_LumW1). Galaxy is the NED preferred name. RA and Dec are the Equatorial coordinates in degrees (J2000). Objtype is the object type of the galaxy candidate. Distance is the distance to the galaxy in Mpc. m_NUV and mErr_NUV are the apparent magnitude and error from GALEX. m_Ks and mErr_Ks are the apparent magnitude and error from 2MASS. m_W1 and mErr_W1 are the apparent magnitude and error from AllWISE. P_3D is the probability that the galaxy is in the volume given the distance of GW event. P_3D_LumW1 is the joint probability within the volume weighted by the WISE1 luminosity of the galaxy (P_3D * P_LumW1). View this GCN Circular online at https://gcn.nasa.gov/circulars/39174. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37182] GRB 250206A: BALROG localization (Fermi Trigger 760564296 / GRB 250206827)
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39173 SUBJECT: GRB 250206A: BALROG localization (Fermi Trigger 760564296 / GRB 250206827) DATE: 25/02/06 20:26:24 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 760564296 at 19:51:31 on 06 Feb. 2025 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) = 222.4 deg Decl.(2000.0) = -63.8 deg The 1 sigma statistical error radius is 2.6 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB250206827/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB250206827/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB250206827/json View this GCN Circular online at https://gcn.nasa.gov/circulars/39173. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37181] GRB 250206A: Fermi GBM Final Real-time Localization
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39172 SUBJECT: GRB 250206A: Fermi GBM Final Real-time Localization DATE: 25/02/06 20:02:04 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 19:51:31 UT on 6 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250206A (trigger 760564296.928588 / 250206827). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 222.1, Dec = -65.0 (J2000 degrees, equivalent to J2000 14h 48m, -65d 00'), with a statistical uncertainty of 1.7 degrees. The angle from the Fermi LAT boresight is 33.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250206827/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250206827/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250206827/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39172. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37180] GRB 250205A: Fermi GBM Observation
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39171 SUBJECT: GRB 250205A: Fermi GBM Observation DATE: 25/02/06 15:42:40 GMT FROM: oindabimukherjee(a)gmail.com O. Mukherjee (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 21:25:33.72 UT on 05 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250205A (trigger 760483538/250205893). which was also detected by SVOM (Saccardi et al. 2025, GCN 39154), Swift XRT (Kennea et al. 2025, GCN 39161), and OSIRIS+/GTC with z = 3.55 (Postigo et al. 2025, GCN 39160). The Fermi GBM on-ground location is consistent with the SVOM position. The angle from the Fermi LAT boresight is 59 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 105 s (50-300 keV). The time-averaged spectrum from T0-63 to T0+75 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.2 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 83 +/- 3 keV. A Band function with Epeak = 80 +/- 5 keV, alpha = -0.2 +/- 0.16 and beta = -3.11 +/- 0.39 fits the spectrum equally well. The event fluence (10-1000 keV) in this time interval is (6.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.38 s in the 10-1000 keV band is 2 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/39171. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37179] GRB 250205A: REM NIR upper limit
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39170 SUBJECT: GRB 250205A: REM NIR upper limit DATE: 25/02/06 13:36:20 GMT FROM: Matteo Ferro at INAF-OAB <matteo.ferro(a)inaf.it> M. Ferro, R. Brivio, P. D’Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 250205A detected by SVOM (Saccardi et al., GCN 39154) and Einstein Probe (Liu et al., GCN 39165) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the J, H, K bands, starting on 2025 February 06 at 00:34:51 UT (i.e. 3.17 hours after the trigger), and lasting for about 1 hour. From preliminary photometry we do not detect any NIR counterpart consistent with the candidate optical/NIR afterglow (Gompertz et al., GCN 39156; Schneider et al., GCN 39157; Palmerio et al., GCN 39159; de Ugarte Postigo et al., GCN 39160; Watson et al., GCN 39162; Busmann et al., GCN 39169), down to the following 3sigma magnitude upper limit: H > 16.5 (Vega; calibrated against the 2MASS catalogue) at a mid-time of t - t0 = 3.6 hr after the trigger. View this GCN Circular online at https://gcn.nasa.gov/circulars/39170. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37178] EP250205a/GRB 250205A: FTW optical and NIR observations of the counterpart
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39169 SUBJECT: EP250205a/GRB 250205A: FTW optical and NIR observations of the counterpart DATE: 25/02/06 13:31:09 GMT FROM: Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann(a)physik.lmu.de> Malte Busmann (LMU), Daniel Gruen (LMU), Brendan O’Connor (Carnegie Mellon U.) and Antonella Palmese (Carnegie Mellon U.) report: We observed the counterpart of EP250205a/GRB 250205A (Saccardi et al., GCN 39154; Gompertz et al., GCN 39156; Schneider and Adami, GCN 39157; Gompertz et al., GCN 39158; Palmerio et al., GCN 39159; de Ugarte Postigo et al., GCN 39160; Kennea et al., GCN 39161; Watson et al., GCN 39162; Liu et al., GCN 39165; Breeveld et al., GCN 39168) with the Three Channel Imager (3KK) at the Fraunhofer Telescope Wendelstein (FTW) in the r, i and J band simultaneously for 40 x 180 s starting at 2025-02-05T23:04:26 UT (1.66 hours after the trigger). We detect the counterpart in the single exposures. In the first exposure at r = (21.95 +/- 0.17) mag i = (21.26 +/- 0.13) mag J = (20.25 +/- 0.16) mag. The r- and i-band manitudes are calibrated against the PS1 catalog and the J-band is calibrated with the 2MASS Catalog. All magnitudes are provided in the AB system and are not corrected for Galactic extinction. We thank Christoph Ries from the Wendelstein Observatory for obtaining these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/39169. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

[vsnet-grb-info 37177] GRB 250205A: Swift/UVOT Upper Limits
by GCN Circulars 06 Feb '25

06 Feb '25

TITLE: GCN CIRCULAR NUMBER: 39168 SUBJECT: GRB 250205A: Swift/UVOT Upper Limits DATE: 25/02/06 12:21:23 GMT FROM: Alice Breeveld at MSSL-UCL <a.breeveld(a)ucl.ac.uk> A. A. Breeveld (UCL-MSSL) and R. Brivio (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of SVOM/ECLAIRs detected burst GRB 250205A 4593 s after the trigger (Saccardi et al., GCN Circ. 39154). The afterglow reported by Gompertz et al., GCN Circ. 39156, Schneider & Adami, GCN Circ. 39157, Palmerio et al., GCN Circ. 39159, de Ugarte Postigo et al., GCN Circ. 39160, Kennea et al., GCN Circ. 39161 and Watson et al., GCN Circ. 39162, is not detected in the single U-band exposure. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposure is: Filter T_start(s) T_stop(s) Exp(s) Mag u 4593 6243 1625 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.046 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/39168. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

1 0

2025

2024

2023

2022

2021

vsnet-grb-info February 2025