September 2022 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 30499] GRB 220930A: Swift/UVOT Upper Limits
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32609 SUBJECT: GRB 220930A: Swift/UVOT Upper Limits DATE: 22/09/30 20:39:10 GMT FROM: Alexander Belles at PSU/Swift <aub1461(a)psu.edu> A. Belles (PSU) and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 220930A 180 s after the BAT trigger (Cenko et al., GCN Circ. 32603). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 32608) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag wh_FC 180 330 147 >20.71 u_FC 338 588 245 >19.95 wh 618 1368 225 >20.93 v 669 1418 97 >18.73 b 594 1343 77 >19.59 u 744 1318 58 >18.99 w1 719 1467 77 >18.83 m2 693 1442 77 >18.59 w2 644 1393 97 >19.10 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.639 in the direction of the burst (Schlegel et al. 1998).

1 0

[vsnet-grb-info 30498] GRB 220930A: Enhanced Swift-XRT position
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32608 SUBJECT: GRB 220930A: Enhanced Swift-XRT position DATE: 22/09/30 15:35:59 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 892 s of XRT Photon Counting mode data and 1 UVOT images for GRB 220930A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 64.71717, +13.34902 which is equivalent to: RA (J2000): 04h 18m 52.12s Dec (J2000): +13d 20' 56.5" with an uncertainty of 2.2 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.

1 0

[vsnet-grb-info 30497] Swift GRB 220930A: Global MASTER-Net observations report
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32607 SUBJECT: Swift GRB 220930A: Global MASTER-Net observations report DATE: 22/09/30 15:08:15 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, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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. Gres, N.M. Budnev (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), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the Swift GRB 220930A ( S. B. Cenko et al., GCN 32603) errorbox 11539 sec after notice time and 11568 sec after trigger time at 2022-09-30 14:24:40 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 69 deg. The sun altitude is -41.3 deg. The galactic latitude b = -25 deg., longitude l = 181 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2105765 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 11659 | MASTER-Amur | C | 180 | 19.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.

1 0

[vsnet-grb-info 30496] GRB 220930A: BOOTES-5/JGT early optical upper limit
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32606 SUBJECT: GRB 220930A: BOOTES-5/JGT early optical upper limit DATE: 22/09/30 13:19:08 GMT FROM: Youdong HU at IAA-CSIC <huyoudong072(a)hotmail.com> Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report: Following the detection of GRB 220930A by Swift (Cenko et al. GCNC 32603), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) observed the GRB location starting on Sep. 30, 11:13:05 UT (~ 73 s after trigger). In the early co-added image (18 x 10 s exposures in the clear filter), no optical afterglow is detected within the enhanced Swift/XRT error region (Evans et al. GCNC 32605) down to 21.0 mag, which is consistent with the limits reported by UVOT (Cenko et al. GCNC 32603) and COATLI (Watson et al. GCNC 32604). We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.

1 0

[vsnet-grb-info 30495] GRB 220930A: Prompt enhanced Swift-XRT position
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32605 SUBJECT: GRB 220930A: Prompt enhanced Swift-XRT position DATE: 22/09/30 12:16:14 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 220930A, we find an enhanced XRT position of the afterglow: RA, Dec: 64.71723, 13.34924 which is equivalent to: RA (J2000) = 04 18 52.14 Dec (J2000) = +13 20 57.3 with an uncertainty of 1.9 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1125809. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.

1 0

[vsnet-grb-info 30494] GRB 220930A: COATLI Upper Limits
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32604 SUBJECT: GRB 220930A: COATLI Upper Limits DATE: 22/09/30 12:09:45 GMT FROM: Alan M Watson at UNAM <alan(a)astro.unam.mx> Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Simone Dichiara (PSU), Tzveti Dimitrova (ASU), Océlotl López (UNAM), Diego González (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report: We observed the field of the Swift/BAT GRB 220930A (Cenko, GCN Circ. 32603) with the COATLI 50-cm telescope and HUITZI f/8 imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (http://coatli.astroscu.unam.mx) from 2022-09-30 11:22 UTC to 11:59 UTC (10.5 to 48 minutes after the trigger), obtaining a total of 1920 seconds of exposure in the r filter. We do not detect any uncataloged sources in the XRT error region (Cenko, GCN Circ. 32603) to a 3-sigma limit of r = 22.5. Our photometry is calibrated against the Pan-STARRS1 catalog, are on an approximate AB system, and are not corrected for Galactic extinction in the direction of the GRB. We thank the COATLI/HUITZI technical team and the staff of the Observatorio Astronómico Nacional.

1 0

[vsnet-grb-info 30493] GRB 220930A: Swift detection of a burst
by GCN Circulars 30 Sep '22

30 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32603 SUBJECT: GRB 220930A: Swift detection of a burst DATE: 22/09/30 11:36:03 GMT FROM: Kim Page at U.of Leicester <klp5(a)leicester.ac.uk> S. B. Cenko (GSFC), A. P. Beardmore (U Leicester), C. Gronwall (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester) and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:11:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 220930A (trigger=1125809). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 64.737, +13.352 which is RA(J2000) = 04h 18m 57s Dec(J2000) = +13d 21' 06" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 20 sec and a secondary peak at about 70 seconds after the trigger time. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 11:14:42.1 UT, 170.0 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 64.7149, 13.3500 which is equivalent to: RA(J2000) = 04h 18m 51.58s Dec(J2000) = +13d 21' 00.0" with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 77 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 3.09e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 179 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.639. Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

1 0

[vsnet-grb-info 30492] Fermi-LAT gamma-ray observations of IceCube-220928A
by GCN Circulars 29 Sep '22

29 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32602 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-220928A DATE: 22/09/29 21:21:24 GMT FROM: Simone Garrappa at DESY <simone.garrappa(a)desy.de> S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and J. Sinapius (DESY-Zeuthen) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the IC220928A high-energy neutrino event (GCN 32599) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2022-09-28 at 12:32:38.30 UT (T0) with J2000 position RA = 207.42 (+1.41 , -2.52) deg, Decl. = 10.43 (+0.98 , -0.98) deg (90% PSF containment). Three cataloged gamma-ray (>100 MeV) sources are located within the 90% IC220928A localization region (4FGL-DR3; The Fermi-LAT collaboration 2022, ApJS, 260, 53). Based on a preliminary analysis of the LAT data over the timescales of 1-day and 1-month prior to T0, these objects are not significantly detected (> 5 sigma). We searched for intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (> 5 sigma) new excess emission (> 100 MeV) at the IC220928A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC220928A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 6.5e-10 ph cm^-2 s^-1 for ~14-years (2008-08-04 to 2022-09-28 UTC), and < 9e-9 (<1.1e-7) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this region will continue. For these observations the Fermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de) and S. Buson (sara.buson at uni-wuerzburg.de). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

1 0

[vsnet-grb-info 30491] IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 29 Sep '22

29 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32601 SUBJECT: IceCube-220928A: Upper limits from a search for additional neutrino events in IceCube DATE: 22/09/29 21:06:32 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-220928A (https://gcn.gsfc.nasa.gov/gcn3/32599.gcn3) in a time range of 1000 seconds centered on the alert event time (2022-09-28 12:24:18.300 UTC to 2022-09-28 12:40:58.300 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-220928A. 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-220928A is 1.3e-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 (2022-09-27 12:32:38.300 UTC to 2022-09-29 12:32:38.300 UTC). In this case, we report a p-value of 1.00, 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-220928A is 1.5e-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<mailto:roc@icecube.wisc.edu>. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)

1 0

[vsnet-grb-info 30490] Konus-Wind detection of GRB 220927A
by GCN Circulars 29 Sep '22

29 Sep '22

TITLE: GCN CIRCULAR NUMBER: 32600 SUBJECT: Konus-Wind detection of GRB 220927A DATE: 22/09/29 20:38:34 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 220927A (Fermi-GBM detection: Fermi GBM Team, GCN 32594; IPN triangulation: Kozyrev et al., GCN 32597) triggered Konus-Wind at T0=20180.364 s UT (05:36:20.364). The burst light curve shows a multipeaked initial emission episode which starts at ~T0-1.9 s and ends at ~T0+8.3 s, followed by a weaker episode at ~T0+35 s. The total burst duration is ~46.7 s. The emission is seen up to 2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB220927_T20180/ As observed by Konus-Wind, the burst had a fluence of 4.18(-1.08,+1.60)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+3.968 s, of 9.37(-2.57,+2.78)x10^-7 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+41.216 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -1.37(-0.77,+2.06), the high energy photon index beta = -2.60(-7.40,+0.35), the peak energy Ep = 40(-22,+15) keV, chi2 = 93/96 dof. The spectrum near the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.97(-0.43,+0.61), the high energy photon index beta = -3.04(-6.96,+0.44), the peak energy Ep = 48(-6,+6) keV, chi2 = 83/94 dof. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.

1 0

2025

2024

2023

2022

2021

vsnet-grb-info September 2022