//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22959 SUBJECT: GRB 180718A short GRB detected by IPN and found in ground analysis of BAT data DATE: 18/07/18 23:38:33 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin and K. Hurley, on behalf of the IPN, A. Y. Lien, D. Palmer, S. Barthelmy, J. Cummings, and H. Krimm, on behalf of the Swift-BAT team, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team, and A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The short-duration GRB 180718A was detected by Fermi (GBM; trigger 553571869), INTEGRAL (SPI-ACS), and Swift (BAT), at about 7065 s UT (01:57:45). We have triangulated this GRB to a GBM-INTEGRAL annulus centered at RA(2000)=260.736 deg (17h22m57s) Dec(2000)=+48.285 deg (+48d17'07"), whose radius is 79.182 +/- 2.067 deg (3 sigma). From the ground analysis using the available Swift/BAT event data from T-1 to T+2 sec, we found a 6.3 sigma detection in an image with intervals from T0-0.026 s to T0+0.165 s and energy range 15-150 keV, where T0 = 2018-07-18 01:57:44.530 UTC. The BAT ground-calculated position of this detection is RA, Dec = 336.019, 2.790 deg which is RA(J2000) = 22h 24m 04.6s Dec(J2000) = +02d 47' 23.3" with an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 25%. The position is consistent with the annulus. The BAT mask-weighted light curve shows a single-pulse structure that starts at ~T0 and ends at ~T+0.1 s. T90 (15-350 keV) is 0.08 +- 0.02 sec (estimated error including systematics). Due to the weakness of this burst, the BAT spectrum is not well-constrained. However, the burst seems to be relatively soft comparing to regular short GRBs. The results of the batgrbproduct analysis are available at https://gcn.gsfc.nasa.gov/notices_s/848489/BA/ A ToO observation with Swift/XRT has been requested. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22960 SUBJECT: GRB 180718A: Fermi GBM detection DATE: 18/07/19 03:53:43 GMT FROM: Rachel Hamburg at UAH R. Hamburg (UAH), P. Veres (UAH), and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 01:57:44.60 UT on 18 July 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180718A (trigger 553571869 / 180718082), which was also detected by the INTEGRAL SPI-ACS and subsequently localized by IPN. Ground analysis of the Swift/BAT data revealed a detection consistent with the IPN annulus (GCN 22959). The angle from the Fermi LAT boresight at the GBM trigger time is 61 degrees. The GBM light curve consists of a single peak with a duration (T90) of about 0.08 s (50-300 keV). The time-averaged spectrum from T0-0.06 s to T0+0.02 s is adequately fit by a Band function with Epeak = 187 +/- 61 keV, alpha = -0.2 +/- 0.4, and beta = -2.3 +/- 0.5. The event fluence (10-1000 keV) in this time interval is (2.3 +/- 0.3)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0-0.05 s in the 10-1000 keV band is 9 +/- 1 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22961 SUBJECT: GRB 180718B: Fermi-LAT detection DATE: 18/07/19 04:24:04 GMT FROM: Judith Racusin at GSFC M. Crnogorcevic (NASA/GSFC/UMD), G. Vianello (Stanford), J. L. Racusin (NASA/GSFC), M. Axelsson (KTH and Stockholm University), and E. Bissaldi (Politecnico and INFN Bari), report on behalf of the Fermi-LAT team: At 18:18:24.46 UT on July, 18, 2018 Fermi-LAT detected high-energy emission from GRB 180718B, which was also detected by Fermi-GBM (trigger 553630709 / 180718763). The best LAT on-ground location is found to be RA, Dec = 44.68, -31.5 (J2000) with an error radius of 0.65 deg (90% containment, statistical error only). This was 50 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. The highest-energy photon is a 300 MeV event which is observed 17 seconds after the GBM trigger. A Swift ToO has been requested for this burst. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it). 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22962 SUBJECT: GRB 180718B: Swift ToO observations DATE: 18/07/19 05:01:17 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/LAT GRB 180718B. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020803 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/LAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22963 SUBJECT: GRB 180718A: Swift ToO observations DATE: 18/07/19 08:58:17 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT GRB 180718A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020802 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22965 SUBJECT: GRB 180718B: Fermi GBM detection DATE: 18/07/19 14:07:31 GMT FROM: Rachel Hamburg at UAH R. Hamburg (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 18:18:24.46 UT on 18 July 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180718B (trigger 553630709 / 180718763). which was also detected by the Fermi LAT (Racusin et al. 2018, GCN 22961). The GBM on-ground location is consistent with the LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 48 degrees. The GBM light curve shows a structured FRED-like peak with a duration (T90) of about 98 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+66 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.73 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 761 +/- 78 keV. A Band function also fits the spectrum with Epeak = 731 +/- 83 keV, alpha = -0.71 +/- 0.05,and beta = -2.79 +/- 0.73. The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.6 s in the 10-1000 keV band is 3.6 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22971 SUBJECT: GRB 180718B: MASTER optical observation DATE: 18/07/20 12:48:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, N.Tiurina, A.Kuznetsov, V.Chazov, I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov Lomonosov Moscow State University,SAI D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB180718.76 36087 sec after notice time and 36087 sec after trigger time at 2018-07-19 04:19:52 UT. On our combined images (1800 s), started 41401 sec after tigger time at 2018-07-19 05:48:25 UT, we not found optical transient within LAT error-box (ra=44.6792 dec=-31.5 r=1) brighter then 20.4. The observations made on zenit distance = 74 degrees, galaxy latitude b = -62 degree. The moon (44 % bright part) below the horizon (The altitude of the Moon is -20 degree ). The sun altitude is -71.7 degree. The object can be observed till sunrise at 2018-07-19 11:33:26 . The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22972 SUBJECT: GRB 180718A: MASTER optical observation DATE: 18/07/20 13:00:27 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs D. Vlasenko, N.Tiurina, E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov Lomonosov Moscow State University,SAI D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) MASTER Global Robotic Net ( Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) inspected GRB180718A (Svinkin et al. GCN22959 ; Fermi trigger 553571869 at 2018-07-18 01:57:44.60 UT , Hamburg et al. GCN22960; Swift BAT position RA,Dec2000= 22h 24m 04.6s +02d 47' 23.3" (Svinkin et al GCN22959; Evans et al. GCN22963) MASTER-Kislovodsk robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Pulkovo Solar Station) was pointed to the GRB180718A (D. Svinkin et al., GCN Circ #22959) 60867 sec after trigger time at 2018-07-18 18:52:12 UT . On our first (180s exposure) set we do not found optical transients within Swift error-box (ra=336.019 dec=2.790 r=0.05) brighter then 18.5. The observations made on zenit distance = 13.51 degrees, galaxy latitude b = -43.86 degree. The moon (39 % bright part) is 15 degrees above the horizon. The distance between moon and object is 142 The sun altitude is -17.5 degree. The errorbox observed 2 nights till 2018-07-19 22:23:00 MASTER-Tavrida robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (SAI Crimea astronomical station) was pointed to the GRB180718A (D. Svinkin et al., GCN Circ #22959) 63704 sec after trigger time at 2018-07-18 19:39:29 UT . On our first (180s exposure) set we do not found optical transients within Swift error-box (ra=336.019 dec=2.790 r=0.05) brighter then 18.6. The observations made on zenit distance = 15.68 degrees, galaxy latitude b = -43.86 degree. The moon (39 % bright part) is 13 degrees above the horizon. The distance between moon and object is 142 The sun altitude is -18 degree. The errorbox observed 2 nights till 2018-07-19 21:25:48 MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the GRB180718A (D. Svinkin et al., GCN Circ #22959) 161995 sec after trigger time at 2018-07-19 22:57:40 UT . On our first (180s exposure) set we do not found optical transients within Swift error-box (ra=336.019 dec=2.790 r=0.05) brighter then 17.5. The observations made on zenit distance = 18.52 degrees, galaxy latitude b = -43.86 degree. The moon (39 % bright part) is 25 degrees above the horizon. The distance between moon and object is 128 The sun altitude is -11.80 degree. The errorbox observed till 2018-07-19 23:53:58 The visibility GRB error box (coord: 336.019 2.790 error_box: 0.05) at trigger time at different MASTER sites: obj: 43.32 sun: -3.21 - Tavrida (Crimea, Russia) obj: 53.60 sun: -39.34 - IAC, Teide, (Tenerife, Spain) obj: 53.56 sun: -45.24 - SAAO (Sutherland, SA) obj: 40.32 sun: 1.49 - Kislovodsk (Russia) obj: 23.50 sun: 16.36 - Ural(Kourovka, Russia) obj: 0.76 sun: 41.53 - Tunka (near Baykal Lake, Russia) obj: -14.45 sun: 55.06 - Amur(Blagoveschensk) obj: 6.93 sun: -51.86 - OAFA (Argentina) The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23030 SUBJECT: GRB 180718A: Swift-XRT observations DATE: 18/07/24 13:37:13 GMT FROM: Boris Sbarufatti at PSU J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 180718A (Svinkin et al. GCN Circ. 22959), collecting 1.5 ks of Photon Counting (PC) mode data between T0+113.7 ks and T0+115.2 ks. No X-ray sources have been detected consistent with being within 296 arcsec of the Swift/BAT position. The 3-sigma upper limit in the field ranges from ~0.005 to ~0.013 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-13 to 5.1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020802. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23031 SUBJECT: GRB 180718B: Swift-XRT observations DATE: 18/07/24 14:21:22 GMT FROM: Boris Sbarufatti at PSU B. Sbarufatti (INAF-OAB/PSU), A. A. Breeveld (UCL-MSSL), Z. Liu (NAOC / U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), A. Tohuvavohu (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 180718B (Crnogorcevic et al. GCN Circ. 22961), collecting 5.0 ks of Photon Counting (PC) mode data between T0+38.9 ks and T0+50.6 ks. Four uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. The UVOT finds no new optical sources at the position of any of the four X-ray sources. Details of these sources are given below: Source 1: RA (J2000.0): 44.7960 = 02:59:11.03 Dec (J2000.0): -31.6692 = -31:40:09.2 Error: 3.0 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: (9.0 +/- 2.4)e-3 ct s^-1 Distance: 705 arcsec from Fermi/LAT position. Flux: (2.79 +/- 0.74)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 2: RA (J2000.0): 44.6153 = 02:58:27.68 Dec (J2000.0): -31.6555 = -31:39:19.9 Error: 6.1 arcsec (radius, 90% conf.) Count-rate: (1.91 [+0.92, -0.71])e-3 ct s^-1 Distance: 593 arcsec from Fermi/LAT position. Flux: (5.1 [+2.4, -1.9])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 3: RA (J2000.0): 44.7970 = 02:59:11.27 Dec (J2000.0): -31.4797 = -31:28:47.0 Error: 4.0 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: (2.80 [+1.14, -0.91])e-3 ct s^-1 Distance: 366 arcsec from Fermi/LAT position. Flux: (1.19 [+0.49, -0.39])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 4: RA (J2000.0): 44.7053 = 02:58:49.28 Dec (J2000.0): -31.4407 = -31:26:26.5 Error: 5.0 arcsec (radius, 90% conf.) Count-rate: (2.51 [+1.10, -0.87])e-3 ct s^-1 Distance: 227 arcsec from Fermi/LAT position. Flux: (5.1 [+2.2, -1.8])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020803. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23216 SUBJECT: GRB 180718A: 15 GHz upper limits from the AMI Short GRB Program DATE: 18/09/10 06:44:13 GMT FROM: Kunal Mooley at NRAO,Caltech J. Bright (Oxford), K. P. Mooley (NRAO, Caltech; Jansky Fellow), R. P. Fender (Oxford) We observed the field of short GRB 180718A (Svinkin et al., GCN 22959) with the AMI Large Array at 15 GHz. Our observation on 2018 Jul 22.03 (UT) (3.95 d post-burst) does not reveal any potential afterglow candidate consistent with the BAT location (Svinkin et al., GCN 22959), and our 3sigma upper limit to the flux density is 180 uJy. We thank the MRAO staff for scheduling these observations. Results from the AMI Short GRB program are posted on the AMI-GRB database available at http://4pisky.org/ami-grb/.