Sponsored by the National Science Foundation
Browse Event Streams | Browse Skyalert Feeds | my Feeds and Alerts

Log in here, or register here.

Portfolio ivo://nasa.gsfc.gcn/SWIFT#BAT_GRB_Pos_518731-949

From the SWIFT stream.
SWIFT GRB alerts
Position is 246.8284,-29.4152 ± 0.05
This portfolio initiated 2012-03-26 20:06:11
Also available is the JSON representation of this portfolio. 		See context in WorldWideTelescope
Each event of the portfolio can be shown as Overview, Params, or XML. Click at the left to select the view.
Overview
Params
XML
None

BAT_GRB_Pos_518731-949

SWIFT alert 61. RA, Dec is (246.8284, -29.4152) ± 0.05.

For full information on the meaning of the parameters in this packet, see here and search for 'TYPE=61'

Burst Intensity/Peak: 6922/250

SWIFT_BAT_GRB_POSITION

Overview
Params
XML
None
GCN Circular 13123 from Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
Trigger:518731
GRB:
Subject:GRB 120327A: Swift detection of a burst with an optical counterpart
B. Sbarufatti (INAF-OAB/PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 02:55:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120327A (trigger=518731). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 246.828, -29.415, which is RA(J2000) = 16h 27m 19s Dec(J2000) = -29d 24' 54" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows 3 main peaks with a total duration of about 60 sec. The peak count rate was ~6500 counts/sec (15-350 keV), at ~38 sec after the trigger. The XRT began observing the field at 02:56:32.2 UT, 75.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 246.86308, -29.41514 which is equivalent to: RA(J2000) = 16h 27m 27.14s Dec(J2000) = -29d 24' 54.5" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 110 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.40 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 1.9 (+1.51/-1.37) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 5.41e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the U filter starting 140 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 16:27:27.47 = 246.86445 DEC(J2000) = -29:24:53.8 = -29.41494 with a 90%-confidence error radius of about 0.64 arc sec. This position is 3.6 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.92 with a 1-sigma error of about 0.15. No correction has been made for the expected extinction corresponding to E(B-V) of 0.34. Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.it). 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.)
Overview
Params
XML
None
GCN Circular 13137 from Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
Trigger:518731
GRB:
Subject:GRB 120327A: Swift-BAT refined analysis
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), B. Sbarufatti (INAF-OAB/PSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120327A (trigger #518731) (Sbarufatti, et al., GCN Circ. 12123). The BAT ground-calculated position is RA, Dec = 246.854, -29.415 deg, which is RA(J2000) = 16h 27m 25.0s Dec(J2000) = -29d 24' 55.5" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 76%. The mask-weighted light curve shows 3 main peaks (two weak peaks, then the main peak). The first starts at ~T-25 sec, peaks at ~T+2 sec; and the second peaks at ~T+18 sec. The main peak starts at ~T+30 sec, peaks at ~T+37 sec, and returns to baseline at ~T+180 sec. T90 (15-350 keV) is 62.9 +- 7.5 sec (estimated error including systematics). The time-averaged spectrum from T-15.79 to T+74.58 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.52 +- 0.06. The fluence in the 15-150 keV band is 3.6 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+37.09 sec in the 15-150 keV band is 3.9 +- 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/518731/BA/

This portfolio has 0 comments:

You need to login to make comments.