GRB190326A

This page lists all entries on GRB190326A in GRBweb

Summary IPN Swift GCN 24009 GCN 24016 GCN 24018 GCN 24020 GCN 24023 GCN 24129

Summary table
Variable Value Source
T0 7:35:28 UTC GCN_circulars,Swift Det
ra 341.6520° Swift
decl 39.9140° Swift
pos_error 1.24e-02° Swift
T90 0.08 s Swift
T90_start 7:35:28 UTC Swift
fluence 6.30e-08 erg/cm² Swift
T100 0.08 s
GBM_located False
mjd 58568.316296296296 GCN_circulars,Swift Det
IPN table
GRB_name GRB190326A
ra 341.6542°
decl 49.9000°
pos_error 5.00e-02°
Swift table
GRB_name GRB190326A
t_trigger 7:35:28 UTC
ra 341.6520°
decl 39.9140°
pos_error 1.24e-02°
T90 0.08 s
fluence 6.30e-08 erg/cm²
GCN 24009 table
GRB_name GRB190326A
GCN_number 24009
Detection_method Swift Det
t_trigger 7:35:28 UTC
ra 341.6520°
decl 39.9030°
Circular_text TITLE: GCN CIRCULAR NUMBER: 24009 SUBJECT: GRB 190326A: Swift detection of a short burst DATE: 19/03/26 07:48:18 GMT FROM: Kim Page at U.of Leicester M. H. Siegel (PSU), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 07:35:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190326A (trigger=895006). Due to an observing constraint, Swift did not slew to the burst. The BAT on-board calculated location is RA, Dec 341.652, +39.903 which is RA(J2000) = 22h 46m 37s Dec(J2000) = +39d 54' 09" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 0.1 sec. The peak count rate was ~7000 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 12:47 UT on 2019 April 13. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 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 24016 table
GRB_name GRB190326A
GCN_number 24016
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 24016 SUBJECT: GRB 190326A: MITSuME Okayama optical upper limits DATE: 19/03/27 06:52:18 GMT FROM: Masafumi Niwano at Tokyo Institute of Tech M. Niwano, K. L. Murata, R. Itoh, Y. Tachibana, K. Morita, K. Iida, K. Shiraishi, R. Adachi, M. Oeda, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration We searched for the optical counterpart of GRB 190326A (M. H. Siegel et al., GCN #24009) with optical three color (g', Rc, and Ic) cameras attached to the MITSuME 50 cm reflector in the Okayama Astrophysical Observatory, Japan. The observation started at 19:01:19 UT which corresponds to 41151 sec since the trigger. We did not find any new point source within the Swift BAT error circle (M. H. Siegel et al., GCN #24009) in all three bands. The obtained 5 sigma upper limits of the optical counterpart are summarize below: T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- 41151 19:33:27 600 >16.8 >16.8 >16.2 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used UCAC-4 catalog for flux calibration.
GCN 24018 table
GRB_name GRB190326A
GCN_number 24018
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 24018 SUBJECT: GRB 190326A: Insight-HXMT/HE detection DATE: 19/03/27 14:06:40 GMT FROM: Qi Luo at IHEP 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 2019-03-26T07:35:28.900 (T0), the Insight-HXMT/HE detected GRB 190326A(trigger ID: HEB190326316) in a routine search of the data, which was also triggered by Swift/BAT(M. H. Siegel et al. ,GCN 24009) and MITSuME (M. Niwano et al. ,GCN 24016). The Insight-HXMT/HE light curve mainly consists of two pulses with a duration (T90) of 0.018 s measured from T0+0.01s. The 1-ms peak rate, measured from T0+0.011 s, is 30499 cnts/sec. The total counts from this burst is 234 counts. URL_LC: http://www.hxmt.org/images/GRB/HEB190326316_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.
GCN 24020 table
GRB_name GRB190326A
GCN_number 24020
Detection_method Swift-BAT Det
ra 341.6520°
decl 39.9140°
Circular_text TITLE: GCN CIRCULAR NUMBER: 24020 SUBJECT: GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR DATE: 19/03/27 21:08:28 GMT FROM: Amy Lien at GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL), G. Younes (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190326A (trigger #895006) (Siegel et al., GCN Circ. 24009). The BAT ground-calculated position is RA, Dec = 341.652, 39.914 deg which is RA(J2000) = 22h 46m 36.6s Dec(J2000) = +39d 54' 50.3" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 57%. The mask-weighted light curve shows a FRED-like pulse structure that starts and peaks at ~T0, and ends at ~T+0.1 s. T90 (15-350 keV) is 0.08 +- 0.03 sec (estimated error including systematics). The time-averaged spectrum from T+0.00 to T+0.10 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index -0.67 +- 0.92, and Epeak of 33.9 +- 4.9 keV (chi squared 97.5 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 6.3 +- 0.8 x 10^-8 erg/cm2 and the 1-sec peak flux measured from T-0.45 sec in the 15-150 keV band is 1.55 +- 0.30 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The unusually soft spectrum (for a short GRB) and the very short duration show resemblance with an SGR. Therefore, we also compare the spectral fit from a blackbody model, which yields a similar reduced chi square (i.e., chi squared 99.89 for 55 d.o.f.) with kT = 9.39 keV. This kT is consistent with small-flare events from SGRs. However, the source location is not really close to the galactic plane (b = -16.9 deg), nor does it match with any known SGRs. If this is a GRB, this is one of the softest short bursts detected by BAT (based on a sample with constrained spectral fits from the 3rd BAT GRB catalog; Lien & Sakamoto et al. 2016). Another BAT-detected short GRB with similar softness and duration is GRB140622A, which was classified to be a short GRB because the XRT light curve is consistent with the normal behavior of a short burst (Sakamoto et al. 2014; Burrows et al. 2014). Unfortunately, due to the observing constraint, we do not have information from XRT/UVOT, and thus it is difficult to determine the burst origin at this point. Further X-ray observations may clarify the physical origin. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/895006/BA/
GCN 24023 table
GRB_name GRB190326A
GCN_number 24023
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 24023 SUBJECT: GRB 190326A: 2.2m CAHA telescope optical limit DATE: 19/03/28 15:59:19 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia Y.-D. Hu, X.-Y.Li, E. Fernandez-Garcia, A. Ayala, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), R. P. Hedrosa and I. Hermelo (CAHA) on behalf of a larger collaboration, report: Following the detection of the short-soft event GRB 190326A by Swift (Siegel et al. GCNC 24009), we triggered the 2.2m telescope (+CAFOS) at the Spanish Calar Alto Observatory (Almeria, Spain). Observations were conducted at high airmass starting on March 28, 04:22:52 UT (i.e. 1.87 day after the trigger). A series of BVRI imaging (500s per filter) shows no optical afterglow down to 21 mag (in the calibrated R-band image) within the Swift/BAT error box (1.6 arcmin, Markwardt et al. GCNC 24020). We acknowledge excellent support from the CAHA staff. This message can be quoted.
GCN 24129 table
GRB_name GRB190326A
GCN_number 24129
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 24129 SUBJECT: GRB 190326A: Swift XRT and UVOT follow-up observations DATE: 19/04/18 17:20:09 GMT FROM: Boris Sbarufatti at PSU B. Sbarufatti (PSU), P. Kuin (MSSL/UCL) and M. H. Siegel (PSU) report on behalf of the Swift-XRT team: Swift has performed XRT and UVOT follow-up observations of BAT detected GRB 190326A (Siegel et al. GCN Circ. 24009), after it came out of the Sun observing constraint. The data were collected between T0+18.91 days and T0+18.98 days, for a total exposure of 1.9 ks in Photon Counting (PC) mode for XRT and with the UVW1 filter for UVOT. No uncatalogued X-ray sources have been detected. The 3-sigma upper limit at the BAT refined position (Markwardt et al. GCN Circ. 24020) is 1.95E-2 ct s^-1, corresponding to a 0.3-10 keV observed flux of 9.75E-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). The UVOT also does not detect any new source at the BAT refined position. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(ks) T_stop(ks) Exp(ks) Mag uvw1 1633 1640 1.89 >20.47 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel et al. 1998). The BAT refined analysis pointed out that the unusually soft spectrum hinted at a possible SGR nature for the source. However, a non detection at T+18.9 days is consistent with the expected behavior of a short GRB, and we conclude that it is more likely that the event was a Gamma Ray Burst. This circular is an official product of the Swift XRT and UVOT teams.