batgrbproduct Analysis for Trigger=277571
Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done of the amount of data for this trigger downloaded to date.
- 3) This page will be updated for up to 8 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.41
Process Start Time (local time): Thu Dec 13 19:27:01 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger277571/GCN5_download_cron
======================================================================
Trigger: 00277571 Segment: 000
BAT Trigger Time: 199503312 [s; MET]
Trigger Stop: 199503392 [s; MET]
UTC: 2007-04-29T01:35:10.078940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 297.687314347276 Dec: -32.3880627129472 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 12.08
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 12.08
Flight Position: [ source = BAT ]
RA: 297.687314347276 Dec: -32.3880627129472 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 297.69094534618 Dec: -32.4218829366764 [deg; J2000]
{ 19h 50m 45.8s , -32d 25' 18.8" }
+/- 2.65461225267492 [arcmin] (estimated 90% radius based on SNR)
+/- 1.42755738972666 [arcmin] (formal 1-sigma fit error)
SNR: 7.54054143215301
RA = 19h 50m 45.8s (297.690945 deg.)
Dec = -32d 25' 19" (-32.421883 deg.)
Angular difference between Flight and Ground position is 2.037533 arcmin
Partial Coding Fraction: 0.6875 [ including projection effects ]
Duration
T90: 168.127999961376 +/- 38.7145649101926
Measured from: -9.11199998855591
to: 159.01599997282 [s; relative to TRIGTIME]
T50: 73.8879999816418 +/- 35.238731412145
Measured from: 0.631999999284744
to: 74.5199999809265 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 3.45199999213219
to: 4.45199999213219 [s; relative to TRIGTIME]
Total Fluence
Measured from: -12.4880000054836
to: 177.368000000715 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.681235 0.697226 0.256285 0.150329
0.079898 0.074391 0.063280 0.053916 [error]
Peak 0.016427 0.025099 0.015487 0.001396
0.006413 0.006080 0.004949 0.004142 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence Power-law 2.27e-07 2.86e-07 2.63e-07 4.22e-07 9.19e-07 1.20e-06 erg/cm2
Error 4.26e-08 3.72e-08 6.43e-08 2.08e-07 1.43e-07 2.77e-07 erg/cm2
Peak flux Power-law 1.74e-01 1.63e-01 1.06e-01 1.06e-01 4.86e-01 5.48e-01 ph/cm2/s
Error 8.45e-02 5.15e-02 4.03e-02 8.19e-02 1.50e-01 1.65e-01 ph/cm2/s
Fluence Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Band 2.25e-07 2.90e-07 2.61e-07 4.07e-07 9.18e-07 1.21e-06 erg/cm2
Error 4.48e-08 3.79e-08 5.14e-08 1.88e-07 1.31e-07 2.83e-07 erg/cm2
Peak flux Band 1.39e-01 1.88e-01 1.13e-01 2.66e-02 4.62e-01 4.66e-01 ph/cm2/s
Error 8.73e-02 5.12e-02 3.32e-02 8.42e-02 1.45e-01 1.34e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.122 0.272 - - 5.20e-04 9.05e-05 71.881 57
CPL 1.992 0.000 4.8 0.0 5.85e-04 0.00e+00 72.325 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.621 0.511 - - 3.76e-03 1.17e-03 54.975 57
CPL 0.140 0.000 58.8 0.0 2.28e-02 0.00e+00 53.734 56
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedom
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
T90 in the 50-300 keV band: 23.936000 sec.
T50 in the 50-300 keV band: 12.608000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 189.856 -12.488 177.368
T90 168.128 -9.112 159.016
T50 73.888 0.632 74.520
Peak 1.000 3.452 4.452
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
297.6909 -32.4219 0.0254 28.2 -134.7 1.4304 7.5 TRIG_00277571
------------------------------------------
Foreground time interval of the image:
-12.488 87.501 (delta_t = 99.989 [sec])
Background time interval of the image:
-68.899 -12.488 (delta_t = 56.411 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
- 4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
- 5) Time of each bin is in the middle of the bin.
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) For long bursts, a spectral fit of the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -12.488 sec. to 177.368 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.12233 ( -0.262798 0.280302 )
Norm@50keV : 5.197523E-04 ( -9.227029E-05 8.879235E-05) )
------------------------------------------------------------
Chi-Squared = 71.88079 using 59 PHA bins.
Reduced chi-squared = 1.261067 for 57 degrees of freedom
Null hypothesis probability = 8.862E-02
Photon flux (15-150 keV) in 189.9 sec: 8.268283E-02 ( -0.0106519 0.0106627 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.19013e-07 ( -1.41164e-07 1.45325e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -12.488 sec. to 177.368 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99198 ( )
Epeak [keV] : 4.75622 ( )
Norm@50keV : 5.846528E-04 ( )
------------------------------------------------------------
Chi-Squared = 72.32521 using 59 PHA bins.
but latest trial 1.49565 gives Chi-Squared = 4.08864
Reduced chi-squared = 1.291522 for 56 degrees of freedom
Null hypothesis probability = 7.003E-02
Photon flux (15-150 keV) in 189.9 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -12.488 sec. to 177.368 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.49105 ( -15.0000 0.00000 )
beta : -2.15023 ( -0.292217 0.280189 )
Epeak [keV] : 16.4089 ( -19.3551 5.31673 )
Norm@50keV : 1.750642E-03 ( -505.513 769846. )
------------------------------------------------------------
Chi-Squared = 71.75587 using 59 PHA bins.
Reduced chi-squared = 1.304652 for 55 degrees of freedom
Null hypothesis probability = 6.408E-02
Photon flux (15-150 keV) in 189.9 sec: 8.275294E-02 ( -0.010692 0.0106409 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.17665e-07 ( -1.27007e-07 1.34873e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 3.448 sec. to 4.456 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.62050 ( -0.503843 0.517715 )
Norm@50keV : 3.755956E-03 ( -1.178730E-03 1.156220E-03) )
------------------------------------------------------------
Chi-Squared = 54.97500 using 59 PHA bins.
Reduced chi-squared = 0.9644737 for 57 degrees of freedom
Null hypothesis probability = 0.551
Photon flux (15-150 keV) in 1.008 sec: 0.485732 ( -0.149187 0.150242 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.53078e-08 ( -1.14104e-08 1.17424e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 3.448 sec. to 4.456 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.140329 ( )
Epeak [keV] : 58.7988 ( )
Norm@50keV : 2.283068E-02 ( )
------------------------------------------------------------
Chi-Squared = 53.73395 using 59 PHA bins.
Reduced chi-squared = 0.9595348 for 56 degrees of freedom
Null hypothesis probability = 0.561
Photon flux (15-150 keV) in 1.008 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 3.448 sec. to 4.456 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.125268 ( -9.87473 5.12527 )
beta : -2.87415 ( -7.12585 4.33027 )
Epeak [keV] : 58.6751 ( -58.5751 894.003 )
Norm@50keV : 2.323565E-02 ( -6.69953 26.0186 )
------------------------------------------------------------
Chi-Squared = 53.72117 using 59 PHA bins.
Reduced chi-squared = 0.9767486 for 55 degrees of freedom
Null hypothesis probability = 0.524
Photon flux (15-150 keV) in 1.008 sec: 0.461526 ( -0.135345 0.155261 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.32449e-08 ( -1.24048e-08 5.94397e-09 ) ergs/cm2
Plot creation:
Thu Dec 13 19:45:09 EST 2007