GRB250207A: Summary Image Light curves Spectra Distribution Others

Analysis Summary

Notes:

• 1) No attempt has been made to eliminate the non-significant decimal places.
• 2) This batgrbproduct analysis is done using the HEASARC data.
• 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.48
    Process Start Time: Thu Jun 19 21:36:31 EDT 2025
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1287821
======================================================================

  Trigger: 01287821      Segment: 000

  BAT Trigger Time: 760583802.368   [s; MET]
      Trigger Stop: 760583803.392   [s; MET]
               UTC: 2025-02-07T01:16:07.335260    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 16.1147840004549   Dec: -12.1587242122474  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    14.23
     Image Trigger?:     NO
     Rate S/N Ratio:     34.5253530032641  [ if not an image trigger ]
     Image S/N Ratio:    14.23

  Analysis Position:   [ source = BAT ]
    RA: 16.1147840004549   Dec: -12.1587242122474  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 16.1002914164675   Dec: -12.1630225311623  [deg; J2000]  
        { 01h 04m 24.1s , -12d 09' 46.9" }
         +/- 0.713524010641872 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.20572868099719 [arcmin] (formal 1-sigma fit error)
    SNR: 49.2645678004417
 
  Angular difference between the analysis and refined position is 0.888304 arcmin
 
  Partial Coding Fraction: 0.7265625    [ including projection effects ]

  Duration
     T90: 41.2119998931885 +/- 16.4965805732257
        Measured from: -3.66400003433228
                   to: 37.5479998588562     [s; relative to TRIGTIME]
     T50: 10.3439999818802 +/- 0.829891554331643
        Measured from: 1.29199993610382
                   to: 11.635999917984     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 6.92799997329712     
                   to: 7.92799997329712     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -6.72399997711182     
                   to: 63.2999999523163     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.243953   1.723195   1.794203   0.614023
           0.060383   0.064384   0.057107   0.047977 [error]
 Peak      0.063317   0.121637   0.122077   0.029037
           0.009084   0.010118   0.009428   0.007369 [error]

     [ fluence units of on-axis counts / fully illuminated detector ] 

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   70.024   -6.724   63.300
T90    41.212   -3.664   37.548
T50    10.344    1.292   11.636
Peak    1.000    6.928    7.928
 
 
====== Spectral Analysis Summary =====================================
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^{Ph_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 both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedo
 
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.246    -0.070      0.070       -           -               -         5.19e-03     -1.94e-04          1.93e-04      65.360   57
CPL     -1.199    -0.117      0.129      999.105    -999.105      -999.105      5.44e-03     -4.19e-04          5.23e-04      66.150   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: CPL)
 
Model Ph_index Ph_90err_low Ph_90err_hi  Epeak  Epeak_90err_low  Epeak_90err_hi  Norm       Nomr_90err_low    Norm_90err_hi    chi2    dof
PL      -1.182     -0.140     0.142       -           -               -         2.31e-02     -1.99e-03          1.99e-03      61.830   57
CPL     -0.212     -0.673     0.808      100.404     -23.446       100.375      6.58e-02     -3.35e-02          8.69e-02      55.410   56
 
 
=== 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         PL   3.66e-07  7.85e-07  1.32e-06  5.12e-06  3.64e-06  7.59e-06   erg/cm2
      90%_error_low -2.89e-08 -3.65e-08 -5.59e-08 -4.96e-07 -1.42e-07 -5.21e-07   erg/cm2
      90%_error_hi   2.98e-08  3.63e-08  5.56e-08  5.32e-07  1.42e-07  5.51e-07   erg/cm2
Peak flux       PL   7.01e-01  8.52e-01  7.51e-01  1.14e+00  2.70e+00  3.44e+00   ph/cm2/s
      90%_error_low -1.12e-01 -8.81e-02 -7.20e-02 -2.09e-01 -2.42e-01 -3.07e-01   ph/cm2/s
      90%_error_hi   1.18e-01  8.72e-02  7.15e-02  2.36e-01  2.43e-01  3.10e-01   ph/cm2/s
 
Fluence        CPL   3.65e-07  7.86e-07  1.30e-06  5.34e-06  3.65e-06  7.63e-06   erg/cm2
      90%_error_low -2.90e-08 -3.65e-08 -3.46e-08 -4.39e-07 -1.52e-07 -1.10e-06   erg/cm2
      90%_error_hi   2.98e-08  3.62e-08  7.71e-08  2.75e-07  1.31e-07  1.83e-07   erg/cm2
Peak flux      CPL   5.63e-01  9.14e-01  8.34e-01  4.91e-01  2.62e+00  2.80e+00   ph/cm2/s
      90%_error_low -1.40e-01 -1.03e-01 -9.18e-02 -2.04e-01 -2.52e-01 -3.30e-01   ph/cm2/s
      90%_error_hi   1.47e-01  1.05e-01  9.38e-02  3.65e-01  2.51e-01  4.18e-01   ph/cm2/s
 
======================================================================

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   16.1003   -12.1630   0.0039    35.4143  -171.1766         4.1439243     49.265 TRIG_01287821                 
 
Foreground time interval of the image:
 -6.724  11.533 (delta_t =  18.257 [sec])
Background time interval of the image:
-239.368  -6.724 (delta_t = 232.644 [sec])

Light Curves

Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.

Full-time range; 1 s binning

Other quick-look light curves:

• 64 ms binning (zoomed)
• 16 ms binning (zoomed)
• 8 ms binning (zoomed)
• 2 ms binning (zoomed)
• SN=5 or 10 s binning (full-time range)
• Raw light curve

Spectra

Notes:

• 1) The fitting includes the systematic errors.
• 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using 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 average DRM

Power-law model

Time interval is from   -6.724 sec. to   63.300 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.2459     ( -0.0699465   0.0704296 )
Norm@50keV  : 5.18801E-03    ( -0.000193623   0.000193268 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   65.36     using 59 bins.
 Reduced chi-squared = 1.14667
# Null hypothesis probability of 2.09e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 70.02 sec: 0.613199 ( -0.024832  0.024983 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.63992e-06 ( -1.41499e-07  1.4165e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -6.724 sec. to   63.300 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.24154     ( -0.116867   0.12908 )
Epeak [keV] : 9999.06      ( -9999.08 -9999.08 )
Norm@50keV  : 5.21118E-03    ( -0.000191934   0.000750022 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   65.43     using 59 bins.
 Reduced chi-squared = 1.16839
# Null hypothesis probability of 1.82e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 70.02 sec: 0.613041 ( -0.013297  0.024941 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.64991e-06 ( -1.52457e-07  1.30613e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    6.928 sec. to    7.928 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.18194     ( -0.139735   0.141947 )
Norm@50keV  : 2.30722E-02    ( -0.00199454   0.00199365 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   61.83     using 59 bins.
 Reduced chi-squared = 1.08474
# Null hypothesis probability of 3.08e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.70154 ( -0.24224  0.24275 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.35315e-07 ( -2.17304e-08  2.18371e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    6.928 sec. to    7.928 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.211964     ( -0.672645   0.807836 )
Epeak [keV] : 100.404      ( -23.4447 100.376 )
Norm@50keV  : 6.58383E-02    ( -0.0334982   0.0868745 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.41     using 59 bins.
 Reduced chi-squared = 0.989464
# Null hypothesis probability of 4.97e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 2.61571 ( -0.25182  0.25086 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.24554e-07 ( -2.38158e-08  2.3605e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 41.212 sec.
Hardness ratio (energy fluence ratio) = 1.68663085564

S(15-50 keV) vs. S(50-150 keV) plot

S(15-50 keV)  = 1.1512129e-06
S(50-150 keV) = 2.488666e-06

The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.

Mask shadow pattern

IMX = -7.026230838911420E-01, IMY = 1.090655754059929E-01

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

Time interval of the image:
-239.368000 -6.724000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5609  35.2228    2.1  56.0  -26.6   8.5318   5.6    1.9	Cyg X-1                       
308.1134  40.9491   20.3  49.5  -19.0   0.4194   0.6    0.3	Cyg X-3                       
326.1068  38.2418    5.5  35.5  -17.8   0.9257   2.1    5.7	Cyg X-2                       
 46.6431  19.4289    3.0  42.3  116.9   7.2258   3.9 ------	UNKNOWN                       
302.8978  47.9533    2.5  54.3  -10.9   4.1086   4.6 ------	UNKNOWN                       
348.3971 -12.1864    2.6  34.9 -123.2   2.3875   4.4 ------	UNKNOWN                       

Pre-slew background subtracted image of 15-350 keV band

Time interval of the image:
-6.724000 11.532610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.6526  35.2904    6.0  55.9  -26.5  -0.6228  -1.9    6.1	Cyg X-1                       
308.0891  40.9930    6.2  49.6  -18.9   0.2992   1.9    2.6	Cyg X-3                       
326.3053  38.3494    5.2  35.4  -17.5  -0.1945  -2.2    6.5	Cyg X-2                       
 33.0361  57.7292    2.8  44.0   57.6   1.2802   4.1 ------	UNKNOWN                       
 39.1593  32.9429    2.1  35.7   95.2   0.9366   5.6 ------	UNKNOWN                       
 16.1003 -12.1630    0.2  35.4 -171.2   4.1437  49.3 ------	UNKNOWN                       
 12.8693 -12.8790    2.1  34.9 -165.6   0.4310   5.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
93.932600 846.532600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 17.5755  24.9219    2.6  37.1   12.6   6.0173   4.4 ------	UNKNOWN                       
341.2695  -8.4135    2.4  34.5  -76.8   8.2315   4.8 ------	UNKNOWN