//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23225 SUBJECT: GRB 180914A: Fermi-LAT detection DATE: 18/09/14 19:27:09 GMT FROM: Elisabetta Bissaldi at INFN,Bari E. Bissaldi (Politecnico & INFN Bari), D. Kocevski (NASA/MSFC), and N. Omodei (Stanford Univ) report on behalf of the Fermi-LAT team: At 12:31:47.25 UT on September 14, 2018 Fermi-LAT detected high-energy emission from GRB 180914A, which was also detected by Fermi-GBM (trigger 558621112 / 180914522). The best LAT on-ground location is found to be RA, Dec = 52.74, -5.26 (J2000) with an error radius of 0.40 deg (90 % containment, statistical error only). This was 87 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 correlated with the trigger with high significance. The highest-energy photon is a 5.1 GeV event which is observed 630 s 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: 23227 SUBJECT: GRB 180914A: Fermi GBM detection DATE: 18/09/14 23:47:15 GMT FROM: Suraj Poolakkil at UAH S.Poolakkil(UAH), C. Meegan (UAH) and E. Bissaldi (Politecnico & INFN Bari) report on behalf of the Fermi GBM Team: "At 12:31:47.25 UT on 14 September 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180914A (trigger 558621112/ 180914522), which was also detected by the Fermi LAT (E. Bissaldi et al. 2018, GCN 23225). The GBM on-ground location is consistent with the LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 86 degrees. The GBM light curve shows multiple peaks with a duration (T90) of about 122.4 s (50-300 keV). The time-averaged spectrum from T0+1.0 s to T0+156.7 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.70 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 296 +/- 7 keV. The event fluence (10-1000 keV) in this time interval is (9.152 +/- 0.128)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+21.37 s in the 10-1000 keV band is 12.73 +/- 0.36 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: 23228 SUBJECT: GRB 180914A: Tiled Swift observations DATE: 18/09/14 23:48:16 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 180914A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00074 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: 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: 23229 SUBJECT: GRB 180914A: Swift-XRT observations DATE: 18/09/15 07:59:26 GMT FROM: Paolo D'Avanzo at INAF-OAB V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester), Z. Liu (NAOC / U. Leicester) 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 180914A (Bissaldi et al. GCN Circ. 23225) in a series of observations tiled on the sky. The total exposure time is 1.8 ks, distributed over 7 tiles; the maximum exposure at a single sky location was 546 s. The data were collected between T0+40.9 ks and T0+43.0 ks, and are entirely in Photon Counting (PC) mode. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 53.0804 = 03:32:19.29 Dec (J2000.0): -5.6243 = -05:37:27.5 Error: 5.0 arcsec (radius, 90% conf.) Count-rate: 0.162 [+0.048, -0.040] ct s^-1 Distance: 1791 arcsec from Fermi/LAT position. Flux: (7.7 [+2.3, -1.9])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV) We note the presence of a bright star (with magnitude R~12.7, as reported in the USNOB1 catalogue) about 14" away from Source 1. The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/xrt_products/TILED_GRB00074. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23230 SUBJECT: GRB 180914A: MASTER automatic inspection DATE: 18/09/15 08:31:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, D. Vlasenko, N.Tiurina, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, Lomonosov Moscow State University,SAI A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D.Svinkin (Ioffe Institute, Sankt Petersburg) 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) 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-Tunka robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located near Bykal Lake (Irkutsk University Astrophysical Center) was starting survey on the FERMI GRB180914.52 error-box (Poolakkil et al., GCN #23227). 17768 sec after trigger time at 2018-09-14 17:27:55 UT. The 5-sigma upper limit on our first (180s exposure) set is about 16.0 mag No OT found. MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was starting survey on the LAT GRB180914.52 error-box (ra=03 30 57 dec=-05 15 35 r=0.4, (Bissaldi et al., GCN #23225)). 15521 sec after notice time and 38331 sec after trigger time at 2018-09-14 23:10:38 UT. The 5-sigma upper limit on our first (180s exposure) set is about 18.5 mag The cover map is available at http://observ.pereplet.ru/images/GRB180914A.png No new objects brighter than 18.5 mag were found after the human analysis of automatic candidates. ==================================================================== The galacitc latitude b = 0 deg. The observations made on zenit distance = 54 deg.The moon (31 % bright part) below the horizon (The altitude of the Moon is -19 deg. ). The sun altitude is -59.4 deg. The object can be observed till sunrise at 2018-09-15 04:35:52 THIS BLOCK FOR MASTER-Team USERS ONLY. Link to GRB180914.52 page: https://196.21.94.34//master2/grb.php?not=2018-09-14+18%3A51%3A56.63329&sat=LAT&gcrd=%2852.7375d%2C-5.25972d%29&eb=0.4&trig=2018-09-14+12%3A31%3A47.25&n=GRB180914.52 Long transients in E.B. https://196.21.94.34//master2/trans.php?wh=transients.coord2000@%27%3C%2852.7375d%2C-5.25972d%29%2C0.8d%3E%27%3A%3Ascircle+and+transients.datetime%3E%3D%272018-09-14+12%3A31%3A47.25%27&class=9&t2=LAT+GRB180914.52+optical+counterpart+candidate Short transients in E.B. https://196.21.94.34//master2/trans3.php?wh=transients3.coord2000@%27%3C%2852.7375d%2C-5.25972d%29%2C0.8d%3E%27%3A%3Ascircle+and+transients3.datetime%3E%3D%272018-09-14+12%3A31%3A47.25%27&class=-1&t2=LAT+GRB180914.52+optical+counterpart+candidate Two tube transients in E.B. https://196.21.94.34//master2/trans2.php?wh=transients2.coord2000@%27%3C%2852.7375d%2C-5.25972d%29%2C0.8d%3E%27%3A%3Ascircle+and+transients2.datetime%3E%3D%272018-09-14+12%3A31%3A47.25%27&class=0&t2=LAT+GRB180914.52+optical+counterpart+candidate Undef. objects 1 image https://196.21.94.34//master2/aobj.php?wh=stars.coord2000@%27%3C%2852.7375d%2C-5.25972d%29%2C0.8d%3E%27%3A%3Ascircle+and+stars.class=0+and+stars.status+and+stars.proc_id=578290&t2=LAT+GRB180914.52+1+image+optical+counterpart+candidate This message can be cited //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23235 SUBJECT: GRB 180914A: RATIR Optical and NIR Observations DATE: 18/09/15 19:44:14 GMT FROM: Eleonora Troja at GSFC Eleonora Troja (GSFC), Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesus Gonzalez (UNAM), Carlos Roman-Zuniga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report: We observed the field of the LAT GRB 180914A (Bissaldi, et al., GCN 23225) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronomico Nacional on Sierra San Pedro Martir from 2018/09 15.29 to 2018/09 15.50 UTC (18.54 to 23.57 hours after the Fermi trigger), obtaining a total of 3.00 hours exposure in the r and i bands and 1.24 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (D'Elia, et al., GCN 23229), in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following upper limits (3-sigma): r > 24.2 i > 24.1 Z > 22.7 Y > 22.5 J > 22.0 H > 21.6 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronomico Nacional in San Pedro Martir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23247 SUBJECT: IPN Triangulation of GRB 180914A (long) DATE: 18/09/17 18:26:55 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley, on behalf of the IPN, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 180914A (Bissaldi et al., GCN Circ.23225; Poolakkil et al., GCN Circ. 23227) was detected by Fermi (GBM trigger 558621112), INTEGRAL (SPI-ACS), Konus-Wind, and Mars-Odyssey (HEND) at about 45107 s UT (12:31:47). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 53.107 (03h 32m 26s) -5.687 ( -5d 41' 14") Corners: 52.535 (03h 30m 08s) -5.415 ( -5d 24' 53") 53.948 (03h 35m 48s) -8.072 ( -8d 04' 21") 53.677 (03h 34m 42s) -5.954 ( -5d 57' 13") 52.197 (03h 28m 47s) -3.090 ( -3d 05' 23") --------------------------------------------- The error box area is 2.36 sq. deg, and its maximum dimension is 5.28 deg (the minimum one is 45.48 arcmin). The Sun distance was 119 deg. This box may be improved. The distance between the XRT source (D'Elia et al., GCN circ. 23229) and the box center is 4.1 arcmin, supporting the association of the transient and the GRB. We thank Robert Wilson for noticing this. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB180914_T45107/IPN The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23248 SUBJECT: GRB 180914A: AstroSat CZTI detection DATE: 18/09/17 18:46:42 GMT FROM: Vidushi Sharma at IUCAA V. Sharma, T. Khanam and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed the detection of a long GRB 180914A, which was also detected by Fermi (LAT: Bissaldi E. et al., GCN 23225 and GBM: Poolakkil S. et al., GCN 23227), Swift (XRT: D'Elia V. et al., GCN 23229) and IPN Triangulation (Hurley K. et al., GCN 23247). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 12:32:08.500 UT. The measured peak count rate is 874 cts/s above the background in combined data of four quadrants, with a total of 27940 cts. The local mean background count rate was 609 cts/s. Using cumulative rates, we measure a T90 of 125.4 s. In preliminary analysis, we find that 2142 compton events are associated with this event. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23254 SUBJECT: Konus-Wind observation of GRB 180914A DATE: 18/09/18 15:46:59 GMT FROM: Anastasia Tsvetkova at Ioffe Institute A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline on behalf of the Konus-Wind team, report: The long GRB 180914A (Fermi-LAT detection: Bissaldi, Kocevski & Omodei , GCN 23225; Fermi GBM detection: Poolakkil, Meegan & Bissaldi, GCN 23227; IPN Triangulation: Hurley et al., GCN 23247; AstroSat CZTI detection: Sharma at al., GCN 23248) triggered Konus-Wind at T0=45119.268 s UT (12:31:59.268). The burst light curve shows multiple pulses in the interval from T0 - 11 s to T0+143 s. A total duration of the burst (T100) is ~154 s. The emission is seen up to ~20 MeV. As observed by Konus-Wind, the burst had a fluence of 9.08(-0.51,+0.57)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+13.408 s, of 6.05(-1.28,+1.29)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+147.200 s) is best fit in the 20 keV - 20 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with  alpha = -0.68(-0.12,+0.13), and Ep = 301(-25,+30) keV (chi2 = 136/98 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.43 (chi2 = 134/97 dof). The spectrum near the peak count rate (measured from T0+7.936 to T0+16.128 s) is best fit in the 20 keV - 20 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with  alpha = -0.51(-0.13,+0.14), and Ep = 356(-31,+37) keV (chi2 = 112/98 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.82 (chi2 = 112/97 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180914_T45119/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.