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

[vsnet-grb-info 30705] Konus-Wind detection of GRB 221022C
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32901 SUBJECT: Konus-Wind detection of GRB 221022C DATE: 22/10/31 14:54:50 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 short-duration GRB 221022C (IPN triangulation: Svinkin et al., GCN Circ. 32857) triggered Konus-Wind at T0=52903.608 s UT (14:41:43.608). The burst light curve shows a multipeaked structure, which starts at T0-88 ms and has a total duration of ~128 ms. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB221022_T52903/ As observed by Konus-Wind, the burst had a fluence of 8.55(-1.23,+1.68)x10^-7 erg/cm2, and a 16-ms peak flux, measured from T0-0.012 s, of 2.01(-0.39,+0.47)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). Since the main fraction of the burst emission was detected before the trigger, the spectral analysis was performed using the KW 3-channel light curve data. Modelling the KW 3-channel time-integrated spectrum (measured from T0-0.088 s to T0+0.040 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), yields alpha = -0.09(-0.28,+0.40) and Ep = 548(-86,+121) keV. All the quoted errors are at the 68% confidence level. All the quoted values are preliminary.

1 0

[vsnet-grb-info 30704] GRB 221029A: Fermi GBM Final Localization
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32900 SUBJECT: GRB 221029A: Fermi GBM Final Localization DATE: 22/10/31 13:42:50 GMT FROM: Joe Mangan at UCD <joseph.mangan(a)ucdconnect.ie> The Fermi GBM team reports the detection of a likely Long GRB. "At 01:05:27.31 UT on 29 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB221029A (trigger 688698332 / 221029045). The on-ground calculated location, using the GBM trigger data, is RA = 53.3, DEC = -44.9 (J2000 degrees, equivalent to 3h 33m, -44d 54'), with a statistical uncertainty of 1 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 72 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221029045/…

1 0

[vsnet-grb-info 30703] GRB 221028A: Swift-XRT refined Analysis
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32899 SUBJECT: GRB 221028A: Swift-XRT refined Analysis DATE: 22/10/31 07:29:01 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> V. D'Elia (SSDC & INAF-OAR), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Sbarufatti (INAF-OAB), A. D'Ai (INAF-IASFPA) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 5.6 ks of XRT data for GRB 221028A (Lien et al. GCN Circ. 32874), from 92 s to 28.1 ks after the BAT trigger. The data comprise 23 s in Windowed Timing (WT) mode (the first 2 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 314.2027, +41.0898 which is equivalent to: RA (J2000): 20 56 48.64 Dec(J2000): +41 05 23.3 with an uncertainty of 3.5 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=2.04 (+0.13, -0.12). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.5 (+0.5, -0.4). The best-fitting absorption column is 2.4 (+1.0, -0.8) x 10^22 cm^-2, in excess of the Galactic value of 7.8 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 8.2 x 10^-11 (1.3 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.4 (+1.0, -0.8) x 10^22 cm^-2 Galactic foreground: 7.8 x 10^21 cm^-2 Excess significance: 3.3 sigma Photon index: 1.5 (+0.5, -0.4) If the light curve continues to decay with a power-law decay index of 2.04, the count rate at T+24 hours will be 8.3 x 10^-6 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.8 x 10^-16 (1.1 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01131910. This circular is an official product of the Swift-XRT team.

1 0

[vsnet-grb-info 30702] GRB 221028A: 1.3m DFOT Optical upper limit
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32898 SUBJECT: GRB 221028A: 1.3m DFOT Optical upper limit DATE: 22/10/31 07:20:02 GMT FROM: Amit Kumar Ror at ARIES <mitturor77894(a)gmail.com> Amit Kumar Ror, Snehlata, Rahul Gupta, S. B. Pandey, Amar Aryan, Ankur Ghosh, Dimple, and Kuntal Misra (ARIES) report: We observed Swift-BAT detected GRB 221028A (Lien et al. GCN 32874) using the 2Kx2K CCD Imager mounted on the 1.3m Devasthal Fast Optical Telescope (DFOT) located at the Devasthal observatory of Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2022-10-28 at 15:17:46, i.e., around 2 hours after the BAT trigger. We have taken multiple frames, each having an exposure time of 300 sec in the R filter. We did not detect any new source within the XRT error circle in our stacked image. We obtain the following 3-sigma upper limit in the stacked image. Date Start (UT) T_start-T0 (hours) Filter Exp time (sec) Limiting magnitude =============================================================== 2022-10-28 15:17:46 ~2 R 300x6 > 21.5 The magnitude is not corrected for the Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalog. The non-detection of the optical afterglow is consistent with Kumar et al. GCNs 32876, 32886; Hu et al. GCN 32878; Lipunov et al. GCN 32879; Strausbaugh et al. GCN 32881; Niwano et al. GCN 32883; Watson et al. GCN no. 32888; Belkin et al. GCN 32889; Odeh GCN 32894; and Komesh et al. GCN 32897. This circular may be cited.

1 0

[vsnet-grb-info 30700] GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32897 SUBJECT: GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits DATE: 22/10/31 02:47:47 GMT FROM: Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh(a)nu.edu.kz> T. Komesh (NU), B. Grossan (UCB, NU), Z. Maksut (NU), M. Krugov (FAI), report on behalf of the Energetic Cosmos Laboratory: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 221028A on receipt of an automated GCN / BAT position alert, observing in Sloan g', r' and i' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations at UT 2022-10-28 13:47:19, 1852 s after the BAT trigger. Observations were made under partially cloudy conditions, beginning with the target at an altitude of 82 deg. No new or changing sources consistent with the XRT position (Lien 2022, GCN 32874) were detected. Note that these observations provide essentially full-time coverage, simultaneous in all three bands. We report the following results: start time t-t0(s) end time UL g' UL r' ULi' exposure_time (s) ------------ -------- ----------- ------ ------ ----- ------ 13:47:19 1852 13:48:19 19.3 18.9 18.7 60 13:48:19 1912 13:58:19 20.3 19.4 20.0 600 start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL gives the 5 sigma upper limit sensitivity in magnitudes for an image with individual exposure time (first row) and for images co-added to the given exposure time (second row). The given upper limit values are derived from the average calibration with only 2-4 standard stars per co-added frame, and no other analysis or corrections. ---------------------------------- NU = Nazarbayev University, Nur-Sultan, Kazakhstan UCB = University of California, Berkeley, USA FAI = Fesenkov Astrophysical Institute, Kazakhstan This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.

1 0

[vsnet-grb-info 30701] GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32896 SUBJECT: GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits DATE: 22/10/31 02:35:10 GMT FROM: Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh(a)nu.edu.kz> T. Komesh (NU), B. Grossan (UCB, NU), Z. Maksut (NU), M. Krugov (FAI), report on behalf of the Energetic Cosmos Laboratory: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 221028A on receipt of an automated GCN / BAT position alert, observing in Sloan g', r' and i' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14).We started observations at UT 2022-10-28 13:47:19, 1852 s after the BAT trigger. Observations were made under partially cloudy conditions, beginning with the target at an altitude of 82 deg. No new or changing sources consistent with the XRT position (Lien 2022, GCN 32874) were detected. Note that these observations provide essentially full-time coverage, simultaneous in all three bands. We report the following results: start time t-t0(s) end time UL g' UL r' ULi' exposure_time (s) ------------ -------- ----------- ------ ------ ----- ------ 13:47:19 1852 13:48:19 19.3 18.9 18.7 60 13:48:19 1912 13:58:19 20.3 19.4 20.0 600 start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL gives the 5 sigma upper limit sensitivity in magnitudes for an image withindividual exposure time (first row) and for images co-added to the given exposure time (second row). The given upper limit values are derived from the average calibration with only 2-4 standard stars per co-added frame, and no other analysis or corrections. ---------------------------------- NU = Nazarbayev University, Nur-Sultan, Kazakhstan UCB = University of California, Berkeley, USA FAI = Fesenkov Astrophysical Institute, Kazakhstan This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.

1 0

[vsnet-grb-info 30696] GRB 221028A: Correction to GCN 32893 - Fluence and flux are for 50-150 keV
by GCN Circulars 31 Oct '22

31 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32895 SUBJECT: GRB 221028A: Correction to GCN 32893 - Fluence and flux are for 50-150 keV DATE: 22/10/31 01:55:30 GMT FROM: Amy Lien at GSFC <amy.y.lien(a)nasa.gov> The fluence for the time averaged spectrum and the 1-s peak flux quoted in the BAT refined analysis for GRB 221028A (Palmer et al., GCN Circ. #32893) should be for the energy range of 50-150 keV, instead of the 15-150 keV written in the original circular. In other words, it should be "The fluence in the 50-150 keV band is 1.51 +- 0.14 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.56 sec in the 50-150 keV band is 0.8 +- 0.2 ph/cm2/sec." We apologize for the typos and any confusion this may cause.

1 0

[vsnet-grb-info 30697] GRB 221028A: AKO Optical Upper Limit
by GCN Circulars 30 Oct '22

30 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32894 SUBJECT: GRB 221028A: AKO Optical Upper Limit DATE: 22/10/30 20:24:14 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 <mshodeh(a)gmail.com> Mohammad Odeh at Al-Khatim Astronomical Observatory (AKO), operated by the International Astronomical Center (IAC), in Abu Dhabi, the United Arab Emirates. We observed the GRB 221028A (Lien et al., GCN 32874) with our 0.36m telescope on 30 October from 15:39 to 16:44 (UT). We obtained exposures in the B, V, and Ic filters and did not detect any afterglow within XRT localization (Lien et al., GCN 32874). This is consistent with the reported non-detections of (Hu et al., GCN 32878; Lipunov et al., GCN 32879; Strausbaugh et al., GCN 32881; Niwano et al., GCN 32883; Kumar et al., GCN 32886; Watson et al., GCN 32888; Belkin et al., GCN 32889). Each image consists of seven stacked frames, each frame is a 3-minute exposure. The obtained upper limits are as follows: Mid Time (UT), Filter, Lim. Mag. 2022-10-30T16:16:06Z, B, > 18.3 2022-10-30T16:13:03Z, V, > 19.6 2022-10-30T16:09:22Z, Ic, > 20.2

1 0

[vsnet-grb-info 30699] GRB 221028A, Swift-BAT refined analysis
by GCN Circulars 30 Oct '22

30 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32893 SUBJECT: GRB 221028A, Swift-BAT refined analysis DATE: 22/10/30 16:04:53 GMT FROM: Amy Lien at GSFC <amy.y.lien(a)nasa.gov> D. M. Palmer (LANL), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 221028A (trigger #1131910) (Lien et al., GCN Circ. 32874). The BAT ground-calculated position is RA, Dec = 314.198, 41.082 deg which is RA(J2000) = 20h 56m 47.5s Dec(J2000) = +41d 04' 56.0" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%. The mask-weighted light curve shows a short pulse that starts and peaks at ~T0 and ends at ~T+2, followed by several overlapping pulses that lasts till ~T+84 s. The structure resembles those of short GRBs with extended emission. T90 (15-350 keV) is 57.1 +- 15.0 sec (estimated error including systematics). Due to current detector issues, data below ~50 keV are inaccurate. Thus, only data above 50 keV are used for spectral analysis. The time-averaged spectrum from T-0.1 to T+84.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.367 +- 0.325. The fluence in the 15-150 keV band is 1.51 +- 0.14 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.56 sec in the 15-150 keV band is 0.8 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1131910/BA/

1 0

[vsnet-grb-info 30698] GRB 221027B: Swift-BAT refined analysis
by GCN Circulars 30 Oct '22

30 Oct '22

TITLE: GCN CIRCULAR NUMBER: 32892 SUBJECT: GRB 221027B: Swift-BAT refined analysis DATE: 22/10/30 16:03:48 GMT FROM: Amy Lien at GSFC <amy.y.lien(a)nasa.gov> C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 221027B (trigger #1131397) (Lien et al., GCN Circ. 32867). The BAT ground-calculated position is RA, Dec = 225.601, 47.451 deg which is RA(J2000) = 15h 02m 24.2s Dec(J2000) = +47d 27' 04.4" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 45%. The mask-weighted light curve shows a structure with two pulses that start at ~T-6 s and end at ~T+4 s. The first weaker peak occurs at ~T-5 s, followed by the main peak that occurs at ~T0. T90 (15-350 keV) is 8.66 +- 1.10 sec (estimated error including systematics). The time-averaged spectrum from T-5.98 to T+4.20 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.39 +- 0.19. The fluence in the 15-150 keV band is 5.8 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band is 3.4 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1131397/BA/

1 0

2025

2024

2023

2022

2021

vsnet-grb-info October 2022