Gamma-ray Burst 190331A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sun 31 Mar 19 02:14:58 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     895813,   Seg_Num: 0
  GRB_RA:           28.576d {+01h 54m 18s} (J2000),
                    28.850d {+01h 55m 24s} (current),
                    27.867d {+01h 51m 28s} (1950)
  GRB_DEC:         +27.619d {+27d 37' 10"} (J2000),
                   +27.713d {+27d 42' 48"} (current),
                   +27.374d {+27d 22' 27"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       450 [cnts]    Image_Peak=69 [image_cnts]
  TRIGGER_DUR:     0.064 [sec] 
  TRIGGER_INDEX:   10418     E_range: 25-100 keV
  BKG_INTEN:       16802 [cnts]
  BKG_TIME:        8065.34 SOD {02:14:25.34} UT
  BKG_DUR:         8 [sec]
  GRB_DATE:        18573 TJD;    90 DOY;   19/03/31
  GRB_TIME:        8077.50 SOD {02:14:37.50} UT
  GRB_PHI:         -82.47 [deg]
  GRB_THETA:        18.76 [deg]
  SOLN_STATUS:     0x20000003
  RATE_SIGNIF:     26.01 [sigma]
  IMAGE_SIGNIF:    8.80 [sigma]
  MERIT_PARAMS:     +1  +0  +0  -4  +2  -1 -100  +0 -86  +0 
  SUN_POSTN:         9.27d {+00h 37m 05s}   +3.99d {+03d 59' 39"}
  SUN_DIST:         30.18 [deg]   Sun_angle= -1.3 [hr] (East of Sun)
  MOON_POSTN:      314.86d {+20h 59m 26s}  -18.68d {-18d 40' 48"}
  MOON_DIST:        85.28 [deg]
  MOON_ILLUM:      24 [%]
  GAL_COORDS:      139.60,-33.21 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       36.38, 14.88 [deg] ecliptic lon,lat of the burst (or transient)
  COMMENTS:        SWIFT-BAT GRB Coordinates.  
  COMMENTS:        This is a rate trigger.  
  COMMENTS:        A point_source was found.  
  COMMENTS:        This does not match any source in the on-board catalog.  
  COMMENTS:        This does not match any source in the ground catalog.  
  COMMENTS:        This is a GRB.  
  COMMENTS:        This trigger occurred at longitude,latitude = 128.58,20.34 [deg].  
  COMMENTS:           
  COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=575691282).  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 31 Mar 19 02:15:05 UT
  NOTICE_TYPE:     Fermi-GBM Flight Position
  RECORD_NUM:      44
  TRIGGER_NUM:     575691282
  GRB_RA:           19.417d {+01h 17m 40s} (J2000),
                    19.686d {+01h 18m 45s} (current),
                    18.719d {+01h 14m 53s} (1950)
  GRB_DEC:         +32.367d {+32d 22' 00"} (J2000),
                   +32.468d {+32d 28' 04"} (current),
                   +32.104d {+32d 06' 13"} (1950)
  GRB_ERROR:       12.48 [deg radius, statistical plus systematic]
  GRB_INTEN:       387 [cnts/sec]
  DATA_SIGNIF:     12.50 [sigma]
  INTEG_TIME:      0.512 [sec]
  GRB_DATE:        18573 TJD;    90 DOY;   19/03/31
  GRB_TIME:        8077.57 SOD {02:14:37.57} UT
  GRB_PHI:         352.00 [deg]
  GRB_THETA:        40.00 [deg]
  DATA_TIME_SCALE: 0.5120 [sec]
  HARD_RATIO:      0.37
  LOC_ALGORITHM:   3 (version number of)
  MOST_LIKELY:      93%  GRB
  2nd_MOST_LIKELY:   3%  GRO_J0422_32
  DETECTORS:       1,0,0, 1,0,0, 0,0,0, 0,0,0, 0,0,
  SUN_POSTN:         9.27d {+00h 37m 05s}   +3.99d {+03d 59' 39"}
  SUN_DIST:         30.10 [deg]   Sun_angle= -0.7 [hr] (East of Sun)
  MOON_POSTN:      314.86d {+20h 59m 26s}  -18.68d {-18d 40' 48"}
  MOON_DIST:        80.33 [deg]
  MOON_ILLUM:      24 [%]
  GAL_COORDS:      129.34,-30.18 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       30.57, 22.30 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190331093/quicklook/glg_lc_medres34_bn190331093.gif
  COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
  COMMENTS:        This trigger occurred at longitude,latitude = 170.62,14.65 [deg].  
  COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=895813).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 31 Mar 19 02:15:19 UT
  NOTICE_TYPE:     Fermi-GBM Ground Position
  RECORD_NUM:      57
  TRIGGER_NUM:     575691282
  GRB_RA:           37.880d {+02h 31m 31s} (J2000),
                    38.170d {+02h 32m 41s} (current),
                    37.129d {+02h 28m 31s} (1950)
  GRB_DEC:         +33.290d {+33d 17' 24"} (J2000),
                   +33.374d {+33d 22' 28"} (current),
                   +33.069d {+33d 04' 09"} (1950)
  GRB_ERROR:       7.05 [deg radius, statistical only]
  DATA_SIGNIF:     15.30 [sigma]
  DATA_INTERVAL:   2.048 [sec]
  GRB_DATE:        18573 TJD;    90 DOY;   19/03/31
  GRB_TIME:        8077.57 SOD {02:14:37.57} UT
  GRB_PHI:          14.00 [deg]
  GRB_THETA:        31.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   4153 (Gnd S/W Version number)
  SUN_POSTN:         9.27d {+00h 37m 05s}   +3.99d {+03d 59' 39"}
  SUN_DIST:         39.86 [deg]   Sun_angle= -1.9 [hr] (East of Sun)
  MOON_POSTN:      314.86d {+20h 59m 27s}  -18.68d {-18d 40' 46"}
  MOON_DIST:        94.82 [deg]
  MOON_ILLUM:      24 [%]
  GAL_COORDS:      145.91,-25.08 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       46.25, 17.42 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190331093/quicklook/glg_lc_medres34_bn190331093.gif
  POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_575691282.fits
  COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
  COMMENTS:        In the LAT Field-of-view.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
  COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=895813).  
  

• GCN NOTICE
  

  TITLE:           GCN/FERMI NOTICE
  NOTICE_DATE:     Sun 31 Mar 19 02:23:53 UT
  NOTICE_TYPE:     Fermi-GBM Final Position
  RECORD_NUM:      0
  TRIGGER_NUM:     575691282
  GRB_RA:           35.860d {+02h 23m 26s} (J2000),
                    36.153d {+02h 24m 37s} (current),
                    35.100d {+02h 20m 24s} (1950)
  GRB_DEC:         +36.510d {+36d 30' 36"} (J2000),
                   +36.597d {+36d 35' 48"} (current),
                   +36.283d {+36d 16' 60"} (1950)
  GRB_ERROR:       6.10 [deg radius, statistical only]
  GRB_DATE:        18573 TJD;    90 DOY;   19/03/31
  GRB_TIME:        8077.57 SOD {02:14:37.57} UT
  GRB_PHI:           8.00 [deg]
  GRB_THETA:        29.00 [deg]
  E_RANGE:         44.032 - 279.965 [keV]
  LOC_ALGORITHM:   41531 (Gnd S/W Version number)
  SUN_POSTN:         9.28d {+00h 37m 06s}   +4.00d {+03d 59' 47"}
  SUN_DIST:         40.89 [deg]   Sun_angle= -1.8 [hr] (East of Sun)
  MOON_POSTN:      314.93d {+20h 59m 44s}  -18.67d {-18d 39' 56"}
  MOON_DIST:        94.28 [deg]
  MOON_ILLUM:      24 [%]
  GAL_COORDS:      142.85,-22.78 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       45.75, 21.01 [deg] ecliptic lon,lat of the burst (or transient)
  LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190331093/quicklook/glg_lc_medres34_bn190331093.gif
  LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn190331093/quicklook/glg_locplot_all_bn190331093.png
  COMMENTS:        Fermi-GBM Final Position.  
  COMMENTS:        This Notice was ground-generated -- not flight-generated.  
  COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
  COMMENTS:        This notice was generated completely by automated pipeline processing.  
  COMMENTS:        In the LAT Field-of-view.  
  COMMENTS:        This is likely a Short GRB.  
  COMMENTS:           
  COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=895813).  
  

• GCN Circular #24027
  K. L. Page (U Leicester), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
  At 02:14:37.50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190331A (trigger=895813). Swift did not slew immediately due to an observing constraint. The BAT on-board calculated location is RA, Dec 28.576, +27.619 which is

     RA(J2000) = 01h 54m 18s
     Dec(J2000) = +27d 37' 10"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a bright multi-peaked structure with a duration of about 5 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger.
  Due to a Sun observing constraint, Swift cannot slew to the BAT position until 18:15 UT on 2019 June 12. There will thus be no XRT or UVOT data for this trigger before this time.
  Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 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/)
• GCN Circular #24030
  D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
  Using the data set from T-599 to T+986 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190331A (trigger #895813) (Page et al., GCN Circ. 24027). The BAT ground-calculated position is RA, Dec = 28.573, 27.635 deg which is

     RA(J2000)  =  01h 54m 17.4s
     Dec(J2000) = +27d 38' 06.8"
  

  with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 82%.
  The mask-weighted light curve shows a multi-peaked structure that starts at ~T0 and ends at ~T+4.5. The main peak occurs at ~T0. T90 (15-350 keV) is 4.3 +- 0.2 sec (estimated error including systematics).
  The time-averaged spectrum from T-0.1 to T+4.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.24 +- 0.15. The fluence in the 15-150 keV band is 4.5 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 2.8 +- 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/895813/BA/
• GCN Circular #24032
  S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
  "At 02:14:37.57 UT on 31 March 2019, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 190331A (trigger 575691282/ 190331093), which was also detected by the Swift/BAT (Page et al. 2019, GCN 24027). The GBM on-ground location is consistent with the Swift position.
  The angle from the Fermi LAT boresight at the GBM trigger time is 40 degrees.
  The GBM light curve shows multiple peaks with a duration (T90) of about 4.8 s (50-300 keV). The time-averaged spectrum from T0-1.0 s to T0+6.1 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.74 +/- 0.19 and the cutoff energy, parameterized as Epeak, is 214 +/- 47 keV.
  The event fluence (10-1000 keV) in this time interval is (1.343 +/- 0.179)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T-0.06 s in the 10-1000 keV band is 4.6 +/- 0.2 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #24036
  Q. Luo, 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 2019-03-31T02:14:38.000 (T0), the Insight-HXMT/HE detected GRB 190331A(trigger ID: HEB190331093) in a routine search of the data, which was also triggered by Swift/BAT(K. L. Page et al. ,GCN 24027) and Fermi/GBM (M. Niwano et al. ,GCN 24032).
  The Insight-HXMT/HE light curve mainly consists of one pulse with a duration (T90) of 7.65 s measured from T0+0.13 s. The 1-ms peak rate, measured from T0+0.271 s, is 1552 cnts/sec. The total counts from this burst is 1691 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB190331093_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 (record 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 fundedjointly 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.