//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24759 SUBJECT: Fermi trigger No 581478912 / GRB 190606A: AGILE/MCAL observations DATE: 19/06/06 10:15:56 GMT FROM: Alessandro Ursi at INAF/IAPS A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), N. Parmiggiani (INAF/OAS-Bologna), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE Mini-CALorimeter (MCAL) detected the short burst GRB190606.08 (Fermi trigger No 581478912) at T0 = 2019-06-06 01:55:07.80 +/- 0.01 s (UTC). The event lasted about 0.22 s and released a total number of ~660 counts in the detector (in the 0.4-100 MeV energy range), above an average background rate of 660 counts / s. The light curve shows a single sharp peak and can be found at http://www.agilescienceapp.it/notices/GRB_062876_486870907.795776.png. The time-integrated spectrum of the burst in 0.22 s can be fitted in the energy range [0.4-100 MeV] with a single power law with ph.ind = 2.32 -0.12/+0.14, resulting in a reduced chi-square of 1.62 (86 d.o.f.). The burst fluence in the same energy range and time interval is 1.71e-6 erg/cm^2 (90% confidence level). The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24761 SUBJECT: GRB 190606A: Fermi-LAT detection DATE: 19/06/06 15:06:23 GMT FROM: Elisabetta Bissaldi at INFN,Bari E. Bissaldi (Politecnico & INFN Bari), M. Axelsson (KTH & Stockholm Univ.), M. Arimoto (Kanazawa Univ.) and F. Longo (Univ & INFN Trieste) report on behalf of the Fermi-LAT team: "On June 6, 2019, Fermi-LAT detected high-energy emission from GRB 190606A, which was also detected by Fermi-GBM (trigger 581478912 / 190606080) and AGILE-MCAL (Ursi et al., GCN #24759). Due to the large angle with respect to the LAT boresight, the positional error for this GRB is uncertain. The best LAT on-ground location is found to be: RA, Dec 76.54, -0.68 (degrees, J2000) with an error radius of 3.0 deg (90% containment, statistical error only). This was 72 deg from the LAT boresight at the time of the GBM trigger: T0 = 01:55:07.78 UT. The data from the Fermi-LAT show a significant increase in the event rate after the GBM trigger that is spatially correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval T0 - T0+250 s after the GBM trigger is (4.3 +/- 1.9)E-05 ph/cm2/s. The highest-energy photon in this interval is a 1.6 GeV event observed at T0+154 s. The estimated photon index above 100 MeV is 2.5 +/- 0.5. 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: 24764 SUBJECT: GRB 190606A: Fermi GBM detection DATE: 19/06/06 18:05:00 GMT FROM: Oliver J Roberts at USRA/NASA O.J. Roberts (USRA/NASA-MSFC), S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 01:55:07.76 UT on the 6th of June 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 190606A (trigger 581478912 / 190606080), which was also detected by AGILE (Ursi et al. 2019, GCN 24759) and the LAT (Bissaldi et al. 2019, GCN 24761). The GBM on-ground location is consistent with the LAT position. The angle from the Fermi LAT boresight is 72 degrees. The GBM light curve shows a bright short spike with a duration (T90) of about 0.3 s (10-1000 keV). The time-averaged spectrum from T0+0 s to T0+0.3 s is best fit by a Band function with Epeak = 1779 +/- 185 keV, alpha = -0.95 +/- 0.02, and beta = -2.52 +/- 0.21 The event fluence (10-1000 keV) in this time interval is (4.88 +/- 0.08)E-06 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.6 s in the 10-1000 keV band is 118 +/- 3 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24765 SUBJECT: IPN Triangulation of GRB 190606A (short) DATE: 19/06/06 20:06:29 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, K. Hurley, on behalf of the IPN, 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, very bright GRB 190606A (AGILE-MCAL detection: Ursi et al., GCN Circ. 24759; Fermi-LAT detection: Bissaldi et al., GCN Circ. 24761; Fermi-GBM detection: Roberts et al,. GCN Circ. 24764) has been detected by Fermi (GBM; trigger 581478912), Konus-Wind, INTEGRAL (SPI-ACS), and AGILE (MCAL), so far, at about 6904 s UT (01:55:04). We have triangulated it to a Konus-GBM annulus centered at RA(2000)=88.386 deg (05h 53m 33s) Dec(2000)=+21.574 deg (+21d 34' 26"), whose radius is 25.034 +/- 0.198 deg (3 sigma). The LAT position reported by Bissaldi et al. (GCN Circ. 24761) is consistent with the annulus. The annulus combined with the LAT (90 % containment, statistical-only) error circle gives the following error box: -------------------------------------------------------------- RA(2000), deg Dec(2000), deg ------------------------------------------------------------ Center: 76.561 (05h 06m 15s) -0.638 ( -0d 38' 17") Corners: 79.380 (05h 17m 31s) -1.649 ( -1d 38' 57") 79.227 (05h 16m 55s) -2.015 ( -2d 00' 55") 74.072 (04h 56m 17s) +1.026 ( +1d 01' 35") 73.869 (04h 55m 29s) +0.686 ( +0d 41' 09") ------------------------------------------------------------- The error box area is 2.4 sq. deg (a factor of 10 smaller than that of the LAT error circle), and its maximum dimension is 6 deg (the minimum one is 23.7 arcmin). The Sun distance was ~22 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB190606_T06903/IPN/ The time history and spectrum will be given in forthcoming GCN Circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24768 SUBJECT: GRB 190606A: Insight-HXMT/HE detection DATE: 19/06/07 11:05:14 GMT FROM: QiBin Yi at IHEP, HXMT Q. B. Yi, S. Xiao, Q. Luo, C. Cai, C. K. Li, X. B. Li, G. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, X. F. Lu, A. M. Zhang, Y. F. Zhang, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2019-06-06T01:55:07.00 (T0), Insight-HXMT/HE detected GRB 190606A (trigger ID: HEB190606079) in a routine search of the data, which was also triggered by Fermi/GBM (trigger #581478912) and AGILE/MCAL (GCN #24759). The Insight-HXMT/HE light curve mainly consists of multiple pulses with a duration (T90) of 0.12 s measured from T0+0.84 s. The 1-ms peak rate, measured from T0+0.89 s, is 49197 cnts/sec. The total counts from this burst is 2833 counts. Some part of the Insight-HXMT/HE light curve suffers data saturation due to the extreme brightness of this burst. URL_LC: http://www.hxmt.org/images/GRB/HEB190606079_lc.jpg All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24784 SUBJECT: Konus-Wind observation of GRB 190606A DATE: 19/06/11 17:29:11 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The short-duration, very bright GRB 190606A (AGILE-MCAL detection: Ursi et al., GCN Circ. 24759; Fermi-LAT detection: Bissaldi et al., GCN Circ. 24761; Fermi-GBM detection: Roberts et al., GCN Circ. 24764; IPN triangulation: Kozlova et al., GCN 24765) triggered Konus-Wind at T0=6903.8 s UT (01:55:03.800). The burst light curve shows a single pulse which starts at ~T0 and has a total duration of ~0.2 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of 1.16(-0.18,+0.18)x10^-5 erg/cm2, and a 16-ms peak flux, measured from T0+0.034 s, of 1.45(-0.39,+0.35)x10^-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+0.192 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.13(-0.08,+0.09) and Ep = 2373(-665,+939) keV (chi2 = 56/54 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -1.8 (chi2 = 55/53 dof). The spectrum near the maximum count rate (measured from T0 to T0+0.064 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: with alpha = -1.19(-0.10,+0.12) and Ep = 3194(-1324,+2736) keV (chi2 = 32/34 dof). Fitting by a GRB (Band) model yields: the low-energy photon index alpha = -0.88(-0.26,+0.45), the high energy photon index beta = -1.67(-0.27,+0.15), the peak energy Ep = 664(-388,+1038) keV (chi2 = 26/33 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB190606_T06903/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.