GRB150314A

This page lists all entries on GRB150314A in GRBweb

Summary Fermi GBM IPN Swift Fermi LAT GCN 17573 GCN 17574 GCN 17575 GCN 17576 GCN 17577 GCN 17578 GCN 17579 GCN 17580 GCN 17581 GCN 17582 GCN 17583 GCN 17584 GCN 17585 GCN 17586 GCN 17587 GCN 17588 GCN 17590 GCN 17591 GCN 17606 GCN 17614

Summary table
Variable Value Source
GRB_name_Fermi GRB150314205
T0 4:54:50 UTC Fermi_LAT
ra 126.6704° Swift
decl 63.8343° Swift
pos_error 2.20e-04° Swift
T90 10.688 s Fermi_GBM
T90_error 0.143 s Fermi_GBM
T90_start 4:54:51.462 UTC Fermi_GBM
fluence 8.16e-05 erg/cm² Fermi_GBM
fluence_error 1.28e-07 erg/cm² Fermi_GBM
redshift 1.7580
T100 40.79 s
GBM_located False
mjd 57095.20474537037 Fermi_LAT
Fermi GBM table
GRB_name_Fermi GRB150314205
trigger_name bn150314205
ra 126.6700°
decl 63.8342°
pos_error 2.45e+00°
datum 2015-03-14
t_trigger 4:54:50.854 UTC
T90 10.688 s
T90_error 0.143 s
T90_start 4:54:51.462 UTC
fluence 8.16e-05 erg/cm²
fluence_error 1.28e-07 erg/cm²
flux_1024 6.71e+01 erg/cm²/s
flux_1024_error 5.01e-01 erg/cm²/s
flux_1024_time 2.14e+00 erg/cm²/s
flux_64 7.55e+01 erg/cm²/s
flux_64_error 2.04e+00 erg/cm²/s
IPN table
GRB_name GRB150314A
ra 126.6583°
decl 63.8333°
pos_error 5.00e-02°
redshift 1.7580
Swift table
GRB_name GRB150314A
t_trigger 4:55:16 UTC
ra 126.6704°
decl 63.8343°
pos_error 2.20e-04°
T90 14.79 s
fluence 2.20e-05 erg/cm²
redshift 1.7580
Fermi LAT table
GRB_name_Fermi GRB150314205
GRB_name GRB150314A
MET 448001693.0
datum 2015-03-14
t_trigger 4:54:50 UTC
ra 126.6704°
decl 63.8343°
pos_error 4.72e-04°
GCN 17573 table
GRB_name GRB150314A
GCN_number 17573
Detection_method Swift Det
t_trigger 4:55:16 UTC
ra 126.6590°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17573 SUBJECT: GRB 150314A: Swift detection of a bright burst DATE: 15/03/14 05:15:27 GMT FROM: David Palmer at LANL L. M. Z. Hagen (PSU), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team: At 04:55:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150314A (trigger=634795). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 126.659d, +63.833d which is RA(J2000) = 08h 26m 38s Dec(J2000) = +63d 50' 00" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single complex peak structure with a duration of about 15 sec. The peak count rate was ~45000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 04:56:17.9 UT, 85.1 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 126.6756, 63.8321 which is equivalent to: RA(J2000) = +08h 26m 42.14s Dec(J2000) = +63d 49' 55.6" with an uncertainty of 4.8 arcseconds (radius, 90% containment). This location is 26 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT data is not immediately available. Burst Advocate for this burst is L. M. Z. Hagen (lea.zernow.hagen AT gmail.com). 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/too.html.)
GCN 17574 table
GRB_name GRB150314A
GCN_number 17574
Detection_method Optical
ra 126.6707°
decl 63.8342°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17574 SUBJECT: GRB 150314A: KAIT Optical Candidate DATE: 15/03/14 05:40:52 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 150314A (Hagen et al., GCN 17573) starting at 04:57:32 UT, 136 s after the burst. We detect a fading source at position RA= 08:26:40.96 (J2000) DEC= 63:50:03.20 (J2000) which faded from mag R~16.0 to R~17.5 in a time interval of about 10 minutes. We suggest this to be the optical afterglow of GRB 150314A. However, we note that this position is about 11 arcsecond, a bit far away from XRT position, indicating this might be unrelated source. Observations are on going.
GCN 17575 table
GRB_name GRB150314A
GCN_number 17575
Detection_method Swift-XRT Det
ra 126.6704°
decl 63.8343°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17575 SUBJECT: GRB 150314A: Enhanced Swift-XRT position DATE: 15/03/14 09:26:44 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 2271 s of XRT Photon Counting mode data and 4 UVOT images for GRB 150314A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 126.67042, +63.83429 which is equivalent to: RA (J2000): 08h 26m 40.90s Dec (J2000): +63d 50' 03.5" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 17576 table
GRB_name GRB150314A
GCN_number 17576
Detection_method Fermi LAT Det
t_trigger 4:54:50.900 UTC
ra 125.4000°
decl 64.4600°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17576 SUBJECT: GRB 150314A: Fermi-LAT detection DATE: 15/03/14 14:02:47 GMT FROM: Magnus Axelsson at Stockholm U. M. Axelsson (KTH Royal Institute of Technology, Sweden), D. Kocevski (NASA/GSFC) and J. Racusin (NASA/GSFC) report on behalf of the Fermi-LAT team: At 04:54:50.9 UT on March 14, 2015, Fermi-LAT detected high-energy emission from GRB 150314A, which was also detected by Fermi-GBM (trigger 448001693/150314205) and Swift (Hagen et al., GCN 17573), and a possible optical counterpart by KAIT (Zhang et al., GCN 17574). The best LAT on-ground location is found to be RA, Dec 125.40, 64.46 (J2000) with an error radius of 0.85 deg (90% containment, statistical error only) and consistent with the Swift/XRT location. This was ~40 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft. The data from the Fermi-LAT show a significant increase in the event rate within 10 degrees of the Swift/XRT location after the trigger. More than 14 photons above 100 MeV are observed within 500 seconds. The highest-energy photon is a 670 MeV event which is observed 78 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Magnus Axelsson (magnus.axelsson@astro.su.se). 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.
GCN 17577 table
GRB_name GRB150314A
GCN_number 17577
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17577 SUBJECT: GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow DATE: 15/03/14 14:04:24 GMT FROM: Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet A. Trotter, D. Reichart, A. LaCluyze, J. Haislip, V. Hoette, K. Cudworth, D. Harper, R. Kron, T. Linder, R. Russell, E. Struble, A. Aji, T. Berger, A. Dow, A. Foster, N. Frank, K. Ivarsen, M. Maples, J. Moore, M. Nysewander, C. Salemi, and J. A. Crain report: Skynet observed the Swift BAT/XRT localization of GRB 150314A (Hagen et al., GCN 17573, Swift trigger=634795) with the 41" telescope at Yerkes Observatory in WI, USA, starting at 2015-03-14 04:58:22 (t=3.5m post-trigger) and continuing until t=41m post-trigger. Skynet took a total of 17 exposures ranging from 20s to 160s in the g', r' and i' bands. We detect a fading source in all three bands at the position reported by Zheng & Filippenko (GCN 17574). A preliminary light curve is at: http://www.skynet.unc.edu/grb/grb150314a.png Magnitudes are in the AB System, calibrated to 4 APASS stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.035 (Schlafly & Finkbeiner 2011). No further Skynet observations are scheduled.
GCN 17578 table
GRB_name GRB150314A
GCN_number 17578
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 17578 SUBJECT: GRB 150314A: MITSuME Akeno upper limits DATE: 15/03/14 14:14:18 GMT FROM: Taketoshi Yoshii at Tokyo Tech T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, Y. Yano, S. Kurita, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 150314A (L. M. Z. Hagen et al., GCN Circular #17573) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started at 2015-03-14 05:21:32 UT (~5.4 h after the burst). We could not find any new point source within the refined XRT-UVOT alignment error circle (A.P. Beardmore et al., GCN Circular #17575) in all the three bands. The obtained upper-limits are listed below. T0+[sec] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------------------------------- 19292 11:19:44 6840 >21.6 >21.1 >20.1 ----------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration.
GCN 17579 table
GRB_name GRB150314A
GCN_number 17579
Detection_method Fermi GBM Det
t_trigger 4:54:50.850 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 17579 SUBJECT: GRB 150314A: Fermi GBM observation DATE: 15/03/14 15:30:39 GMT FROM: Hoi-Fung Yu at MPE H.-F. Yu (MPE) reports on behalf of the Fermi GBM Team: "At 04:54:50.85 UT on 14 Mar 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150314A (trigger 448001693 / 150314205), which was also detected by the Swift (Hagen et al. 2015, GCN 17573) and Fermi LAT (Axelsson et al. 2015, GCN 17576). The GBM on-ground location is consistent with the Swift position. The trigger resulted in an Autonomous Repoint Request (ARR) that was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight is about 50 degrees. The GBM light curve shows a bright single pulse with a duration (T90) of about 10.7 s (50-300 keV). The time-averaged spectrum from T0+0.002 s to T0+13.472 s is best fit by a Band function with Epeak = 311 +/- 5 keV, alpha = -0.60 +/- 0.01, and beta = -2.32 +/- 0.04. The event fluence (10-1000 keV) in this time interval is (8.53 +/- 0.04)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+2.144 s in the 10-1000 keV band is 67.1 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 17580 table
GRB_name GRB150314A
GCN_number 17580
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17580 SUBJECT: GRB 150314A: Swift/UVOT Detection DATE: 15/03/14 18:04:29 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150314A 95 s after the BAT trigger (Hagen et al., GCN Circ. 17573). We detect a fading source consistent with the XRT position (Beardmore et al. GCN Circ. 17575) and optical detections (Zheng & Filippenko GCN Circ. 17574, Trotter et al. GCN Circ. 17577) that is detected in all but the bluest UVOT filters. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 97 244 144 17.22 +/- 0.03 white 587 781 38 19.13 +/- 0.18 white 5472 5671 196 >21.02 v 75 85 9 15.48 +/- 0.13 v 637 657 19 17.75 +/- 0.33 v 4445 6082 390 >19.77 b 562 756 38 19.28 +/- 0.35 b 5266 5466 196 >20.32 u 307 556 245 18.86 +/- 0.14 u 712 6528 253 >20.14 uvw1 687 6485 412 >20.31 uvm2 4650 6280 391 >20.16 uvw2 613 5877 412 >20.46 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 17581 table
GRB_name GRB150314A
GCN_number 17581
Detection_method Swift-BAT Det
ra 126.6610°
decl 63.8390°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17581 SUBJECT: GRB 150314A Swift-BAT refined analysis DATE: 15/03/14 19:19:53 GMT FROM: Amy Lien at GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (GSFC), L. M. Z. Hagen (PSU), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 150314A (trigger #634795) (Hagen, et al., GCN Circ. 17573). The BAT ground-calculated position is RA, Dec = 126.661, 63.839 deg which is RA(J2000) = 08h 26m 38.6s Dec(J2000) = +63d 50' 21.0" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 34%. The mask-weighted light curve shows a single bright FRED pulse that starts at ~ T-2 s, peaks at ~T0, and ends at ~T+13 s. There are some weak extended emissions that last till ~ T+100 s. T90 (15-350 keV) is 14.79 +- 2.64 sec (estimated error including systematics). The time-averaged spectrum from T-2.17 to T+101.42 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.08 +- 0.03. The fluence in the 15-150 keV band is 2.2 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band is 38.5 +- 0.9 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/634795/BA/
GCN 17582 table
GRB_name GRB150314A
GCN_number 17582
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17582 SUBJECT: GRB 150314A: NOT optical observations DATE: 15/03/14 22:13:53 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), S. Geier (GTC/IAC), K. E. Heintz, J. P. U. Fynbo, D. Malesani (DARK/NBI), P. Jakobsson (U. Iceland) report on behalf of a larger collaboration: We observed the field of GRB 150314A (Hagen et al., GCN 17573) using the 2.56m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 3x300 s R-band images with a median time of 20:48:36 UT on 2015-03-14, i.e., 15.89 hr after the burst, and in a seeing of ~0.9". The optical afterglow (Zheng & Filippenko, GCN 17574; Trotter et al., GCN 17577) is clearly detected in our stacked image, with m(R)=22.7 +/- 0.3 mag, calibrated with USNO B1 catalog. The object is a bit extended in the northwest-southeast direction, indicating that the host galaxy might be emerging at the observational time.
GCN 17583 table
GRB_name GRB150314A
GCN_number 17583
Detection_method Fermi GBM Other
redshift 1.7580
Circular_text TITLE: GCN CIRCULAR NUMBER: 17583 SUBJECT: GRB 150314A: Redshift from OSIRIS/GTC DATE: 15/03/14 23:39:25 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J.P.U. Fynbo (DARK/NBI), C. Thoene (IAA-CSIC), N.R. Tanvir (U. Leicester), R. Sanchez-Ramirez (UPV, IAA-CSIC), J. Gorosabel (UPV-EHU, IAA-CSIC), P. Pessev (ULL, IAC), C. Alvarez Iglesias (ULL, IAC), M.A. Rivero (GRANTECAN) report on behalf of a larger collaboration: We obtained spectroscopy of the afterglow of GRB 150314A (Hagen et al., GCN 17573; Zheng & Filippenko, GCN 17574; Axelsson et al., GCN 17576; Trotter et al., GCN 17577; Xu et al. GCN 17582) using OSIRIS at the 10.4 m GTC telescope in La Palma (Spain). Observations consisted of 3 x 1200 s exposure using the R1000B grism, covering the range between 3700 and 7875 A at a resolution of ~700 (1" slit). The mean observing time was 21:37 UT (16.70 hr after the burst). The spectrum shows a continuum with an average SNR ~ 7 (per resolution element) on which several weak absorption features can be identified. Our best match corresponds to lines of FeII, MgII, MgI as well as AlII, AlIII and CIV at lower significance, all at a common redshift of 1.758, which we propose as the redshift of the GRB. At this redshift, the isotropic equivalent energy is Eiso = 6.74e53 erg considering the fluence reported by Fermi/GBM (Yu et. al GCN 17579) in the (10-1000) keV window.
GCN 17584 table
GRB_name GRB150314A
GCN_number 17584
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17584 SUBJECT: GRB 150314A: P60 observations DATE: 15/03/15 01:06:49 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report: The Palomar 60-inch robotic telescope began automatic follow-up of the location of GRB 150314A (Hagen et al., GCN 17573) at 05:08:40 UT on 2015-03-14, 13.4 minutes after the GRB trigger. A sequence of 60-second r, i, and z exposures were acquired, lasting until 06:36 UT. Another sequence of 180-second g, r, and i exposures was taken between 09:01 UT and 10:54 UT. We detect the optical afterglow reported by Zheng and Filippenko (GCN 17574) in individual exposures from the early sequence as well as in a stack of the later-time exposures. Calibrating to a nearby USNO star (RA=126.701423, dec=63.829609, R2=15.33) gives the following photometry: t_med = 834s : R = 18.59 +/- 0.05 t_med = 1179s : R = 18.96 +/- 0.05 t_med = 1437s : R = 19.06 +/- 0.07 t_med = 1693s : R = 19.41 +/- 0.07 t_med = 1977s : R = 19.59 +/- 0.08 t_med = 18365s : R = 21.73 +/- 0.13 The afterglow fades as approximately t^-0.9 throughout our observations.
GCN 17585 table
GRB_name GRB150314A
GCN_number 17585
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17585 SUBJECT: GRB 150314A: KAIT Optical Observations DATE: 15/03/15 03:00:02 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 150314A (Hagen et al., GCN 17573) starting at 04:57:32 UT, 136 s after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. The afterglow reported by Zheng and Filippenko (GCN 17574) was detected in clear and I band, but not in V band. Useful observations lasted for about 20 minutes before the weather change to be coludy. Preliminary analysis shows that the afterglow decays with a single power (with alpha = -1.12) from the beginning of our observations until about a thousand seconds after the burst. A preliminary light curve is posted at http://astro.berkeley.edu/~zwk/grb/GRB150314A/GRB150314A_kait.png
GCN 17586 table
GRB_name GRB150314A
GCN_number 17586
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17586 SUBJECT: GRB 150314A: Swift-XRT refined Analysis DATE: 15/03/15 03:15:03 GMT FROM: Phil Evans at U of Leicester B. Sbarufatti (INAF-OAB/PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), D.N. Burrows (PSU), J.A. Kennea (PSU) and L.M.Z. Hagen report on behalf of the Swift-XRT team: We have analysed 8.1 ks of XRT data for GRB 150314A (Hagen et al. GCN Circ. 17573), from 78 s to 69.2 ks after the BAT trigger. The data comprise 690 s in Windowed Timing (WT) mode (the first 6 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 17575). The late-time light curve (from T0+4.2 ks) can be modelled with an initial power-law decay with an index of alpha=0.57 (+0.13, -0.20), followed by a break at T+11.6 ks to an alpha of 2.00 (+0.13, -0.12). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.760 (+/-0.026). The best-fitting absorption column is 1.72 (+0.10, -0.09) x 10^21 cm^-2, in excess of the Galactic value of 4.5 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.90 (+/-0.10) and a best-fitting absorption column of 2.3 (+/-0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.3 (+/-0.4) x 10^21 cm^-2 Galactic foreground: 4.5 x 10^20 cm^-2 Excess significance: 8.4 sigma Photon index: 1.90 (+/-0.10) If the light curve continues to decay with a power-law decay index of 2.00, the count rate at T+24 hours will be 0.019 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.3 x 10^-13 (9.8 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00634795. This circular is an official product of the Swift-XRT team.
GCN 17587 table
GRB_name GRB150314A
GCN_number 17587
Detection_method Konus-Wind Det
t_trigger 4:54:51.727 UTC
redshift 1.7580
Circular_text TITLE: GCN CIRCULAR NUMBER: 17587 SUBJECT: Konus-Wind observation of GRB 150314A DATE: 15/03/15 12:48:21 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration, very intense GRB 150314A (Swift-BAT trigger #634795: Hagen et al., GCN 17572; Cummings et al., GCN 17581; Fermi-LAT detection: Axelsson et al., GCN 17576; Fermi-GBM observation: Yu, GCN 17579) triggered Konus-Wind at T0=17691.727 s UT (04:54:51.727). The KW light curve shows a bright multi-peaked pulse with a duration of ~14 s. The emission is visible up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150314_T17691/ As observed by Konus-Wind, the burst had a fluence of 9.1(-0.4,+0.4)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+1.344 s, of 2.2(-0.1,+0.1)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+12.288 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.79 (-0.04,+0.04), the high energy photon index beta = -2.91 (-0.28,+0.18), the peak energy Ep = 350 (-17,+17) keV, chi2 = 142/97 dof. The spectrum near the peak count rate (measured from T0+0.256 to T0+2.048 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.37 (-0.08,+0.09), the high energy photon index beta = -2.81 (-0.27,+0.18), the peak energy Ep = 348 (-27,+27) keV, chi2 = 134/94 dof. Assuming the redshift z=1.758 (de Ugarte Postigo et al., GCN 17583) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~6.9x10^53 erg, the peak luminosity L_iso is ~4.6x10^53 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i, is ~965 keV. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 17588 table
GRB_name GRB150314A
GCN_number 17588
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17588 SUBJECT: GRB 150314A: NOT further optical observations DATE: 15/03/16 04:15:19 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Malesani (DARK/NBI), D. Slumstrup (NOT), P. Jakobsson (U. Iceland) report on behalf of a larger collaboration: We continued to observe the field of GRB 150314A (Hagen et al., GCN 17573) using the 2.56m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 4x600 s R-band images with a median time of 02:16:32 UT on 2015-03-16, i.e., 45.35 hr after the burst, and in the seeing of 1.0"-1.5". The optical afterglow (Zheng & Filippenko, GCN 17574; Trotter et al., GCN 17577) is still detected in our stacked image, with m(R) = 23.9 +/- 0.3 mag, calibrated with the same USNO B1 stars that were used in our previous report (Xu et al., GCN 17582). Together with previous observations (e.g., Perley & Cenko, GCN 17584; Zheng & Filippenko, GCN 17585), so far the object still nicely fits the decaying law of F(t) ~ t^-0.9.
GCN 17590 table
GRB_name GRB150314A
GCN_number 17590
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17590 SUBJECT: GRB 150314A: Early RAPTOR Detection DATE: 15/03/17 00:43:21 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis, of Los Alamos National Laboratory report: The RAPTOR network of robotic optical telescopes made observations of Swift trigger 634795 (Hagen, et al., GCN 17573). Our narrow-field instruments located in Los Alamos, NM, USA, arrived on target at 04:55:20.83 UT, T+27.98 seconds after the BAT trigger time. Our initial 5s exposure shows the counterpart (Zheng, et al., GCN 17574) at an unfiltered magnitude of 13.11 +- 0.02. The source fades steadily, reaching magnitude 15.87 +- 0.09 at T+180.38 s, in agreement with the KAIT lightcurve (Zheng, et al., GCN 17585). We derive a power-law decay slope of -1.50 using 04:54:52.86 as the BAT T0. Our unfiltered magnitudes were calibrated to the USNO-B1 R-band catalog. The optical counterpart is not detected in any of our persistent wide-field monitors during the gamma-ray emitting interval. Typical 3-sigma unfiltered limiting magnitudes during this period were V~9.8 based on comparison to the Tycho-2 V-band catalog.
GCN 17591 table
GRB_name GRB150314A
GCN_number 17591
Detection_method VLA Det
ra 126.6707°
decl 63.8342°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17591 SUBJECT: GRB 150314A: VLA observations DATE: 15/03/17 00:52:29 GMT FROM: Tanmoy Laskar at Harvard U T. Laskar and E. Berger (Harvard) report on behalf of a larger collaboration: "We observed GRB 150314A (Hagen et al; GCN 17573) with the VLA beginning on 2015 March 16.1 UT (1.9 days after the burst). At a mean frequency of 5 GHz, we detect a radio source with a preliminary flux density of ~ 0.05 mJy at RA = 08:26:40.973 +/- 0.005 Dec = +63:50:03.29 +/- 0.08 consistent with the enhanced Swft/XRT position (Beardmore et al.; GCN 17575) and the optical position (Zheng et al.; GCN 17574). Follow-up observations are planned."
GCN 17606 table
GRB_name GRB150314A
GCN_number 17606
Detection_method VLA Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17606 SUBJECT: GRB 150314A: Further VLA observations DATE: 15/03/18 19:12:54 GMT FROM: Tanmoy Laskar at Harvard U T. Laskar and E. Berger (Harvard) report: "We observed GRB 150314A (Hagen et al; GCN 17573) with the VLA beginning on 2015 March 17.2 UT (3.0 days after the burst). No significant radio emission is detected at the enhanced Swft/XRT position (Beardmore et al.; GCN 17575) or the optical position (Zheng et al.; GCN 17574). We therefore confirm the radio source reported in our previous observations (Laskar et al.; GCN 17591) as the radio afterglow. No further follow-up observations are planned."
GCN 17614 table
GRB_name GRB150314A
GCN_number 17614
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17614 SUBJECT: GRB 150314A: GMG observation limit DATE: 15/03/23 05:39:31 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, B. Lun and J.-M. Bai (YNAO) report: We observed the field of GRB 150314A (Hagen et al., GCN 17573) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatory. Observations began from UT 12:22:09.5 14th, March, 2015 (about 7.5 hours after the trigger). We did not detect any optical source at the XRT position down to a limit of R~21.0.