GRB250101A

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: Mon Jun 30 16:38:06 EDT 2025
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1278305
======================================================================

  Trigger: 01278305      Segment: 000

  BAT Trigger Time: 757430604.864   [s; MET]
      Trigger Stop: 757430608.96   [s; MET]
               UTC: 2025-01-01T13:22:50.046640    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 37.0612933026417   Dec: 19.1540778787435  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.96
     Image Trigger?:     NO
     Rate S/N Ratio:     7.21110255092798  [ if not an image trigger ]
     Image S/N Ratio:    6.96

  Analysis Position:   [ source = BAT ]
    RA: 37.0612933026417   Dec: 19.1540778787435  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 37.0568925531058   Dec: 19.1804396819508  [deg; J2000]  
        { 02h 28m 13.7s , +19d 10' 49.6" }
         +/- 1.87371355708652 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.852573406143053 [arcmin] (formal 1-sigma fit error)
    SNR: 12.4034466009089
 
  Angular difference between the analysis and refined position is 1.601251 arcmin
 
  Partial Coding Fraction: 0.4765625    [ including projection effects ]

  Duration
     T90: 34.2159999608994 +/- 6.1976656658517
        Measured from: 0.519999980926514
                   to: 34.7359999418259     [s; relative to TRIGTIME]
     T50: 15.067999958992 +/- 5.86990284714568
        Measured from: 4.58399999141693
                   to: 19.6519999504089     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.952000021934509     
                   to: 1.95200002193451     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.223999977111816     
                   to: 36.4880000352859     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.461399   0.476540   0.226706   0.002744
           0.051862   0.053300   0.044423   0.037489 [error]
 Peak      0.021996   0.042256   0.035274   0.011732
           0.008421   0.009292   0.007992   0.006385 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   36.712   -0.224   36.488
T90    34.216    0.520   34.736
T50    15.068    4.584   19.652
Peak    1.000    0.952    1.952
 
 
====== 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      -2.119    -0.252      0.233       -           -               -         1.85e-03     -3.21e-04          3.12e-04      58.390   57
CPL     -1.567    -0.737      1.213       30.855     -29.078       -30.855      3.99e-03     -3.99e-03          1.83e-02      57.410   56
 
 
=== 1-s peak 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      -1.295     -0.350     0.364       -           -               -         7.08e-03     -1.73e-03          1.73e-03      59.290   57
CPL      1.786     -2.185     4.574       61.498     -12.546        32.843      2.38e-01     -2.38e-01          3.20e+01      52.490   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   1.56e-07  1.97e-07  1.81e-07  2.92e-07  6.33e-07  8.25e-07   erg/cm2
      90%_error_low -2.60e-08 -2.56e-08 -4.16e-08 -1.12e-07 -9.67e-08 -1.68e-07   erg/cm2
      90%_error_hi   2.66e-08  2.54e-08  4.30e-08  1.51e-07  9.92e-08  1.97e-07   erg/cm2
Peak flux       PL   2.39e-01  2.72e-01  2.22e-01  3.02e-01  8.44e-01  1.04e+00   ph/cm2/s
      90%_error_low -9.27e-02 -7.54e-02 -6.00e-02 -1.32e-01 -2.13e-01 -2.55e-01   ph/cm2/s
      90%_error_hi   1.04e-01  7.45e-02  5.97e-02  1.78e-01  2.14e-01  2.58e-01   ph/cm2/s
 
Fluence        CPL   1.51e-07  2.11e-07  1.73e-07  1.06e-07  5.97e-07  6.40e-07   erg/cm2
      90%_error_low -2.82e-08 -3.31e-08 -5.42e-08 -8.81e-08 -1.08e-07 -1.47e-07   erg/cm2
      90%_error_hi   2.81e-08  3.63e-08  4.81e-08  3.49e-07  1.15e-07  3.80e-07   erg/cm2
Peak flux      CPL   1.34e-01  3.51e-01  2.74e-01  3.66e-02  7.92e-01  7.95e-01   ph/cm2/s
      90%_error_low -9.67e-02 -1.04e-01 -8.70e-02 -3.66e-02 -2.15e-01 -2.17e-01   ph/cm2/s
      90%_error_hi   1.23e-01  1.09e-01  8.45e-02  1.08e-01  2.18e-01  2.27e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   37.0569    19.1804   0.0156    31.5280   140.9228         1.2253395     12.403 TRIG_01278305                 
 
Foreground time interval of the image:
 -0.224  35.637 (delta_t =  35.861 [sec])
Background time interval of the image:
-239.864  -0.224 (delta_t = 239.640 [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

Bokeh Plot

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   -0.224 sec. to   36.488 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.11935     ( -0.251877   0.233061 )
Norm@50keV  : 1.85056E-03    ( -0.000320925   0.000312301 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   58.39     using 59 bins.
 Reduced chi-squared = 1.02439
# Null hypothesis probability of 4.24e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 36.71 sec: 0.293978 ( -0.037028  0.037031 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.32535e-07 ( -9.66593e-08  9.92176e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.224 sec. to   36.488 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.56677     ( -0.737219   1.21276 )
Epeak [keV] : 30.8554      ( -29.078 -30.8555 )
Norm@50keV  : 3.98547E-03    ( -0.00398555   0.018304 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.41     using 59 bins.
 Reduced chi-squared = 1.02518
# Null hypothesis probability of 4.23e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 36.71 sec: 0.289204 ( -0.03784  0.037871 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.9678e-07 ( -1.07864e-07  1.1544e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    0.952 sec. to    1.952 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.29485     ( -0.35045   0.362831 )
Norm@50keV  : 7.07963E-03    ( -0.00173024   0.00173019 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   59.29     using 59 bins.
 Reduced chi-squared = 1.04018
# Null hypothesis probability of 3.92e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.843734 ( -0.212586  0.213996 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.00664e-08 ( -1.79781e-08  1.81644e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.952 sec. to    1.952 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.78585     ( -2.23678   4.52247 )
Epeak [keV] : 61.4982      ( -12.2024 33.1864 )
Norm@50keV  : 0.237860    ( -0.263865   32.0058 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   52.49     using 59 bins.
 Reduced chi-squared = 0.937321
# Null hypothesis probability of 6.09e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.792061 ( -0.214824  0.218069 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.10225e-08 ( -1.72783e-08  1.89665e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 34.216 sec.
Hardness ratio (energy fluence ratio) = 0.920640232057

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

S(15-50 keV)  = 3.523468e-07
S(50-150 keV) = 2.8019531e-07

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 = -4.762372881367050E-01, IMY = -3.867131623391962E-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:
-239.864000 -0.224000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.1859  38.3198   46.9  34.3  -68.0   0.1250   0.2    0.7	Cyg X-2                       
267.1220  64.9890    3.4  58.1  -16.2   3.8276   3.3 ------	UNKNOWN

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

Time interval of the image:
-0.224000 35.636600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.0259  38.3867   39.4  34.4  -67.8  -0.0345  -0.3    7.9	Cyg X-2                       
 50.7756  11.3307    2.3  46.0  132.6   1.4949   5.1 ------	UNKNOWN                       
 37.0569  19.1804    0.9  31.5  140.9   1.2250  12.4 ------	UNKNOWN                       
352.5243  30.8171    2.5  18.7 -107.7   0.3497   4.6 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
110.036600 931.997200
933.136000 942.836600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 76.4176  45.9501    2.5  41.9   57.7  15.8464   4.6 ------	UNKNOWN                       
 70.0927  31.4941    2.8  32.1   77.3   7.7173   4.1 ------	UNKNOWN                       
 65.8074  34.4706    3.1  29.7   69.6   6.3285   3.7 ------	UNKNOWN                       
  1.5380  13.9130    2.8  34.4  -76.9   7.5371   4.1 ------	UNKNOWN                       
 10.2721 -21.0358    2.2  48.0 -129.1  22.4720   5.3 ------	UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

Mask shadow pattern

Spacecraft aspect plot

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

Pre-burst image of 15-350 keV band

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

Post-slew image of 15-350 keV band

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