batgrbproduct analysis for trigger=1311764
batgrbproduct Analysis for Trigger=1311764
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 batgrbproduct analysis is using the flight position for the mask-weighting calculation.
- 4) This page will be updated for up to 15 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.48
Process Start Time (local time): Sat May 10 17:16:19 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/prebascript/trigger1311764/GCN5_download_cron
======================================================================
Trigger: 01311764 Segment: 000
BAT Trigger Time: 768522846.208 [s; MET]
Trigger Stop: 768522847.232 [s; MET]
UTC: 2025-05-09T22:33:30.632640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 46.4548923274837 Dec: -38.8534416712175 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 12.76
Image Trigger?: NO
Rate S/N Ratio: 33.1511689085016 [ if not an image trigger ]
Image S/N Ratio: 12.76
Flight Position: [ source = BAT ]
RA: 46.4548923274837 Dec: -38.8534416712175 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 46.4514332572058 Dec: -38.8541816879052 [deg; J2000]
{ 03h 05m 48.3s , -38d 51' 15.1" }
+/- 0.748975089374577 [arcmin] (estimated 90% radius based on SNR)
+/- 0.214515431867764 [arcmin] (formal 1-sigma fit error)
SNR: 45.9674808269424
Angular difference between Flight and Ground position is 0.167613 arcmin
Partial Coding Fraction: 0.96875 [ including projection effects ]
Duration
T90: 55.432000041008 +/- 10.4690432289179
Measured from: -0.99999988079071
to: 54.4320001602173 [s; relative to TRIGTIME]
T50: 15.4800000190735 +/- 2.12720011181467
Measured from: 2.72000014781952
to: 18.200000166893 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.416000008583069
to: 1.41600000858307 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.84799993038177
to: 71.4640001058578 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.194634 1.629883 1.058710 0.319945
0.052244 0.054759 0.047218 0.039609 [error]
Peak 0.062147 0.091068 0.087422 0.024898
0.006930 0.007547 0.006982 0.005420 [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 3.42e-07 6.15e-07 8.47e-07 2.42e-06 2.44e-06 4.23e-06 erg/cm2
Error 2.57e-08 2.69e-08 4.67e-08 2.97e-07 1.11e-07 3.28e-07 erg/cm2
Peak flux Power-law 4.90e-01 6.02e-01 5.38e-01 8.29e-01 1.92e+00 2.46e+00 ph/cm2/s
Error 7.94e-02 5.96e-02 5.38e-02 1.76e-01 1.67e-01 2.29e-01 ph/cm2/s
Fluence Cutoff-PL 3.32e-07 6.24e-07 8.54e-07 1.88e-06 2.41e-06 3.69e-06 erg/cm2
Error 3.10e-08 3.08e-08 4.92e-08 -------- 1.27e-07 6.52e-07 erg/cm2
Peak flux Cutoff-PL 4.55e-01 6.19e-01 5.58e-01 5.68e-01 1.89e+00 2.20e+00 ph/cm2/s
Error 9.53e-02 6.68e-02 6.31e-02 3.81e-01 1.29e-01 3.64e-01 ph/cm2/s
Fluence Band -------- -------- -------- -------- -------- -------- erg/cm2
Error -------- -------- -------- -------- -------- -------- erg/cm2
Peak flux Band 4.67e-01 6.16e-01 5.55e-01 6.32e-01 1.92e+00 2.27e+00 ph/cm2/s
Error -------- -------- -------- -------- -------- -------- ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.538 0.077 - - 3.48e-03 1.46e-04 55.310 57
CPL 1.378 0.256 195.8 0.0 4.18e-03 0.00e+00 54.420 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.164 0.148 - - 1.64e-02 1.40e-03 73.960 57
CPL 0.819 0.511 183.7 0.0 2.40e-02 1.50e-02 72.770 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: 25.984000 sec.
T50 in the 50-300 keV band: 12.032000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 74.312 -2.848 71.464
T90 55.432 -1.000 54.432
T50 15.480 2.720 18.200
Peak 1.000 0.416 1.416
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
46.4514 -38.8542 0.0042 9.4 53.9 2.7061 46.0 TRIG_01311764
------------------------------------------
Foreground time interval of the image:
-2.848 15.193 (delta_t = 18.041 [sec])
Background time interval of the image:
-239.208 -2.848 (delta_t = 236.360 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) The mask-weighted light curves are using the flight position.
- 3) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 4) 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.
- 5) 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.
- 6) 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.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -2.848 sec. to 71.464 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.53765 ( -0.0768767 0.0771401 )
Norm@50keV : 3.48237E-03 ( -0.000145753 0.000145284 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.31 using 59 PHA bins.
# Reduced chi-squared = 0.9703 for 57 degrees of freedom
# Null hypothesis probability = 5.387371e-01
Photon flux (15-150 keV) in 74.31 sec: 0.439288 ( -0.0187455 0.0187794 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.44052e-06 ( -1.11045e-07 1.11559e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.848 sec. to 71.464 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37761 ( -0.306673 0.204605 )
Epeak [keV] : 195.807 ( )
Norm@50keV : 4.18377E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 54.42 using 59 PHA bins.
# Reduced chi-squared = 0.9718 for 56 degrees of freedom
# Null hypothesis probability = 5.348247e-01
Photon flux (15-150 keV) in 74.31 sec: 0.434897 ( -0.020244 0.02025 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.40702e-06 ( -1.28058e-07 1.25079e-07 ) ergs/cm2
Band function
Time interval is from -2.848 sec. to 71.464 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.172092 ( -2.52195 -0.50975 )
beta : -1.60258 ( 1.60076 0.10339 )
Epeak [keV] : 36.2434 ( -16.6458 197.085 )
Norm@50keV : 5.27879E-02 ( -0.0526939 199.605 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 52.50 using 59 PHA bins.
# Reduced chi-squared = 0.9546 for 55 degrees of freedom
# Null hypothesis probability = 5.706193e-01
Photon flux (15-150 keV) in 74.31 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 14.6648 ( )
R^2/D10^2 : 5.17104E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 185.14 using 59 PHA bins.
# Reduced chi-squared = 3.2481 for 57 degrees of freedom
# Null hypothesis probability = 1.846679e-15
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.736e-07 1.445e-08
25- 50 6.754e-07 3.797e-08
50-150 9.784e-07 8.323e-08
15-150 1.827e-06 9.066e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-31.7459 -200)
Norm : 1.78295 (-0.0726695 0.0726695)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.300e-07 1.579e-08
25- 50 6.348e-07 3.032e-08
50-150 1.392e-06 6.614e-08
15-150 2.357e-06 1.066e-07
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.74790 (-1.01697 1.07038)
R1^2/D10^2 : 0.339670 (-0.115143 0.20172)
kT2 [keV] : 30.2883 (-5.02284 8.13857)
R2^2/D10^2 : 3.19906E-03 (-0.0017234 0.00287588)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.012e-07 4.106e-08
25- 50 6.522e-07 6.695e-08
50-150 1.460e-06 3.010e-07
15-150 2.414e-06 4.247e-07
Peak spectrum fit
Power-law model
Time interval is from 0.416 sec. to 1.416 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16412 ( -0.148629 0.147077 )
Norm@50keV : 1.64097E-02 ( -0.00140224 0.00140211 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 73.96 using 59 PHA bins.
# Reduced chi-squared = 1.298 for 57 degrees of freedom
# Null hypothesis probability = 6.489680e-02
Photon flux (15-150 keV) in 1 sec: 1.91700 ( -0.166646 0.166803 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.68217e-07 ( -1.6223e-08 1.6346e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.416 sec. to 1.416 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.818928 ( -0.606059 0.41558 )
Epeak [keV] : 183.702 ( -183.702 -183.702 )
Norm@50keV : 2.39908E-02 ( -0.00855887 0.0214081 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.77 using 59 PHA bins.
# Reduced chi-squared = 1.299 for 56 degrees of freedom
# Null hypothesis probability = 6.544284e-02
Photon flux (15-150 keV) in 1 sec: 1.89133 ( -0.08618 0.17142 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.64653e-07 ( -1.7455e-08 1.7372e-08 ) ergs/cm2
Band function
Time interval is from 0.416 sec. to 1.416 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.819058 ( -0.39131 0.23621 )
beta : -10.00000 ( 10 20 )
Epeak [keV] : 183.726 ( -59.4544 -183.726 )
Norm@50keV : 2.39860E-02 ( -0.00920039 0.0211666 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 72.77 using 59 PHA bins.
# Reduced chi-squared = 1.323 for 55 degrees of freedom
# Null hypothesis probability = 5.461066e-02
Photon flux (15-150 keV) in 1 sec: 1.91638 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
XSPEC: quit
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 19.3904 (-2.20438 2.54128)
R^2/D10^2 : 9.87558E-02 (-0.0323959 0.047445)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.244e-09 1.238e-09
25- 50 3.534e-08 4.205e-09
50-150 9.802e-08 1.486e-08
15-150 1.406e-07 1.580e-08
Thermal bremsstrahlung (OTTB)
XSPEC12>exit
XSPEC: quit
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 200.000 (-20.4198 -200)
Norm : 7.82479 (-0.684289 0.684289)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.949e-08 4.710e-09
25- 50 3.749e-08 9.880e-09
50-150 8.222e-08 4.032e-08
15-150 1.392e-07 5.339e-08
Double BB
XSPEC12>exit
XSPEC: quit
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.08208 (-1.81608 2.49656)
R1^2/D10^2 : 1.46389 (-0.897774 2.64264)
kT2 [keV] : 29.2527 (-5.63263 11.0668)
R2^2/D10^2 : 2.23138E-02 (-0.014377 0.0237325)
------------------------------------------------------------
Reduced chi-squared =
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.497e-08 6.634e-09
25- 50 3.524e-08 1.249e-08
50-150 1.159e-07 5.397e-08
15-150 1.661e-07 6.757e-08
Plot creation:
Sat May 10 17:20:03 EDT 2025