batgrbproduct analysis for trigger=1420873

batgrbproduct Analysis for Trigger=1420873

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 (local time): Sat Feb 28 18:15:16 EST 2026
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1420873
======================================================================

  Trigger: 01420873      Segment: 000

  BAT Trigger Time: 786670824.064   [s; MET]
      Trigger Stop: 786670836.224   [s; MET]
               UTC: 2025-12-05T23:39:47.254060    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 200.243464502567   Dec: 29.9625366465604  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.81
     Image Trigger?:     NO
     Rate S/N Ratio:     10  [ if not an image trigger ]
     Image S/N Ratio:    7.81

  Flight Position:   [ source = BAT ]
    RA: 200.243464502567   Dec: 29.9625366465604  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 200.261996135953   Dec: 29.9146706066339  [deg; J2000]  
        { 13h 21m 02.9s , +29d 54' 52.8" }
         +/- 1.95135434614745 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.871954167258503 [arcmin] (formal 1-sigma fit error)
    SNR: 11.7044892114539
 
  Angular difference between Flight and Ground position is 3.029282 arcmin
 
  Partial Coding Fraction: 0.453125    [ including projection effects ]

  Duration
     T90: 125 +/- 757.542243046551
        Measured from: 752.93599998951
                   to: 877.93599998951     [s; relative to TRIGTIME]
     T50: 74 +/- 809.365801106026
        Measured from: 802.93599998951
                   to: 876.93599998951     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 8.93599998950958     
                   to: 9.93599998950958     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -4.06400001049042     
                   to: 878.93599998951     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.080847   0.042085   0.039996  -0.115862
           0.180212   0.186617   0.156878   0.131259 [error]
 Peak      0.028632   0.013523   0.021688   0.006749
           0.008952   0.009377   0.008158   0.007007 [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 8.04e-10 8.21e-09 7.58e-08 4.63e-06 3.12e-07 4.71e-06   erg/cm2
              Error -4.41e+02 -4.41e+02 -4.41e+02 -4.41e+02 -4.41e+02 -4.41e+02   erg/cm2
Peak flux Power-law 1.38e-01 1.56e-01 1.26e-01 1.71e-01 4.82e-01 5.90e-01   ph/cm2/s
              Error 1.11e-01 7.87e-02 9.44e-02 2.22e-01 2.14e-01 2.62e-01   ph/cm2/s
 
Fluence   Cutoff-PL 2.33e-09 9.27e-10 9.36e-10 3.00e-09 3.33e-09 3.34e-08   erg/cm2
              Error -4.41e+02 -4.41e+02 -------- -------- -------- --------   erg/cm2
Peak flux Cutoff-PL 1.42e-01 1.54e-01 1.24e-01 1.89e-01 4.86e-01 6.13e-01   ph/cm2/s
              Error 1.11e-01 8.27e-02 7.22e-02 1.70e-01 2.20e-01 2.63e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   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    9.827    0.000    -      -           5.97e-09 0.00e+00   57.770 57
CPL -10.000    0.000     150.7    0.0      8.85e-05 3.52e-04   56.990 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.302    0.863    -      -           4.04e-03 1.72e-03   51.600 57
CPL   2.287    1.072     100.2    0.0      1.10e-03 2.47e-02   51.380 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: 17.280000 sec.
T50 in the 50-300 keV band: 8.448000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100  883.000   -4.064  878.936
T90   125.000  752.936  877.936
T50    74.000  802.936  876.936
Peak    1.000    8.936    9.936

Click here for the BAT GCN circular template

Estimated redshift from machine learning (Ukwatta et al. 2016) - may take a few minute to calcaulte

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  200.2620    29.9147   0.0164    26.0034    98.9112         1.7505566     11.704 TRIG_01420873                 
 
Foreground time interval of the image:
 -4.064  64.637 (delta_t =  68.701 [sec])
Background time interval of the image:
-239.064  -4.064 (delta_t = 235.000 [sec])

Lightcurves

Notes:

1) The mask-weighted light curves are using the flight position.
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)

Quad-rate summed light curves (from T0-300s to T0+1000s)

Spectral Evolution

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   -4.064 sec. to  878.936 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 9.82727     ( -9.82727   -9.82727 )
Norm@50keV  : 5.97231E-09    ( -5.97231e-09   -5.97231e-09 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.77     using 59 bins.
 Reduced chi-squared = 1.01351
# Null hypothesis probability of 4.47e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 883 sec: 1.44215E-03 ( -0.00144215  0.00501693 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.11516e-07 ( 883  3.48843e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -4.064 sec. to  878.936 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -9.99983     ( 10   10 )
Epeak [keV] : 150.712      ( -150.639 -150.639 )
Norm@50keV  : 8.84950E-05    ( -8.91183e-05   0.000614909 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   56.99     using 59 bins.
 Reduced chi-squared = 1.01768
# Null hypothesis probability of 4.38e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 883 sec: 1.48702E-03 ( -0.00148702  0.00358956 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.3263e-09 ( 0  0 ) ergs/cm2

Band function

Time interval is from   -4.064 sec. to  878.936 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  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]    : 1.63529  (-1.87037  -1.87037)
R^2/D10^2   : 40.5906  (-40.6343   -40.6343)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.59     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.53e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.468e-08   2.287e-08
25- 50  1.122e-09   7.104e-10
50-150  1.515e-14   8.675e-15
15-150  5.580e-08   2.383e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 2.45413       (-2.43647      -2.43647)
Norm        : 15.7608       (-16.886     -16.886)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   57.62     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.52e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.114e-08   2.763e-08
25- 50  1.303e-09   7.466e-10
50-150  1.561e-13   6.494e-14
15-150  5.244e-08   1.883e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 1.66656        (-1.66443      2.43848)
R1^2/D10^2  : 33.6153        (-34.389      243028)
kT2 [keV]   : 199.363        (-199.363      -199.363)
R2^2/D10^2  : 1.27785E-06    (-1.35137e-06   2.5178e-05)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   55.51     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 4.55e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.947e-08   1.581e-08
25- 50  1.276e-08   8.477e-10
50-150  2.988e-07   4.918e-08
15-150  3.610e-07   4.587e-08

Peak spectrum fit

Power-law model

Time interval is from    8.936 sec. to    9.936 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.30225     ( -0.883096   0.841966 )
Norm@50keV  : 4.03863E-03    ( -0.00172645   0.00172208 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   51.60     using 59 bins.
 Reduced chi-squared = 0.905263
# Null hypothesis probability of 6.77e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.482024 ( -0.212981  0.214335 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.98924e-08 ( -1.86203e-08  1.90191e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    8.936 sec. to    9.936 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.28744     ( -1.30159   0.842968 )
Epeak [keV] : 100.171      ( -9999.36 -9999.36 )
Norm@50keV  : 1.10333E-03    ( -0.00110334   0.0483544 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   51.38     using 59 bins.
 Reduced chi-squared = 0.9175
# Null hypothesis probability of 6.50e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 0.485925 ( -0.217313  0.222128 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.00396e-08 ( -1.9795e-08  1.97368e-08 ) ergs/cm2

Band function

Time interval is from    8.936 sec. to    9.936 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  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]    : 24.0149  (-24.1047  35.2204)
R^2/D10^2   : 1.15340E-02  (-0.0113525   0.387922)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   54.07     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 5.86e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.180e-09   8.210e-10
25- 50  6.555e-09   4.336e-09
50-150  2.816e-08   1.927e-08
15-150  3.590e-08   2.473e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 199.363       (-199.363      -199.363)
Norm        : 1.99732       (-0.865117     0.865134)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   52.07     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.60e-01 with 57 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.973e-09   3.213e-09
25- 50  9.567e-09   6.625e-09
50-150  2.098e-08   1.362e-08
15-150  3.552e-08   2.367e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.08812        (-4.32213      10.5893)
R1^2/D10^2  : 0.910843        (-0.882998      379.39)
kT2 [keV]   : 36.2905        (-34.7808      -36.5914)
R2^2/D10^2  : 2.86217E-03    (-0.00278134   0.0100693)
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   50.80     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 6.36e-01 with 55 degrees of freedom
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.100e-09   3.394e-09
25- 50  8.160e-09   4.113e-09
50-150  2.951e-08   1.916e-08
15-150  4.277e-08   2.381e-08

Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)

Power-law model

 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.61164     ( -0.226917   0.232617 )
Norm@50keV  : 1.57649E-03    ( -0.000216648   0.000213043 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   61.20     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 3.28e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 68.7 sec: 0.203323 ( -0.026166  0.0261967 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.01148e-06 ( -1.48345e-07  1.50412e-07 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.61830     ( -0.233722   0.228797 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 1.57428E-03    ( -0.00127473   0.00266484 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   61.21     using 59 bins.
 Reduced chi-squared = 
# Null hypothesis probability of 2.95e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 68.7 sec: 0.203384 ( -0.02622  0.026071 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.00823e-06 ( -1.55818e-07  1.5338e-07 ) ergs/cm2

Band function

 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

S(25-50 keV) vs. S(50-100 keV) plot

S(25-50 keV)  = 8.21e-09
S(50-100 keV) = 7.58e-08

T90 vs. Hardness ratio plot

T90                                   = 125 sec.
Hardness ratio (energy fluence ratio) = 9.23264

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 0.520551
Count Ratio (50-100 keV) / (15-25 keV) = 0.494712

Mask shadow pattern

IMX = -7.556306271289044E-02, IMY = -4.819182467561735E-01

TIME vs. PHA plot around the trigger time

TIME vs. DetID plot around the trigger time

100 us light curve (15-350 keV)

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:
-239.064000 -4.064000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9728 -15.6224    1.2  38.1 -104.7   8.0522   9.7    1.1	Sco X-1                       
254.5975  35.2724    6.9  46.0  174.8   1.1546   1.7    8.0	Her X-1                       
176.4810  -9.4915    2.4  41.4   14.1   2.3239   4.8 ------	UNKNOWN                       
258.1666  -4.8384    2.3  45.4 -127.7   5.7589   5.0 ------	UNKNOWN

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

Time interval of the image:
-4.064000 64.636600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9586 -15.6633   10.9  38.1 -104.6  -0.2834  -1.1    1.8	Sco X-1                       
254.5165  35.2485    5.4  46.0  174.8  -0.4261  -2.1    6.3	Her X-1                       
200.2620  29.9147    1.0  26.0   98.9   1.7504  11.7 ------	UNKNOWN                       
205.3427  -5.0576    2.6  15.5  -16.3   0.4287   4.5 ------	UNKNOWN                       
256.9669  21.8316    2.1  43.4 -166.2   0.8595   5.5 ------	UNKNOWN                       
255.5288  17.9966    1.9  41.3 -160.9   0.9029   6.2 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
128.036590 870.036600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4180  35.1911    9.2  45.4 -151.1  -2.1675  -1.3    9.3	Her X-1                       
201.0640  42.3096    3.0  12.4  143.2   3.3533   3.8 ------	UNKNOWN                       
256.4309  56.5710    4.2  47.0  179.1   5.7789   2.8 ------	UNKNOWN                       
236.4674   6.2811    2.3  41.5 -102.2  19.7793   4.9 ------	UNKNOWN

Plot creation:
Sun Mar  1 23:11:30 EST 2026