GRB240204A: 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: Sat Mar  9 13:59:16 EST 2024
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1212898
======================================================================

  Trigger: 01212898      Segment: 000

  BAT Trigger Time: 728752103.488   [s; MET]
      Trigger Stop: 728752104.512   [s; MET]
               UTC: 2024-02-04T15:07:50.633620    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 104.280141711717   Dec: 1.06112010114358  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    14.47
     Image Trigger?:     NO
     Rate S/N Ratio:     61.9031501621686  [ if not an image trigger ]
     Image S/N Ratio:    14.47

  Analysis Position:   [ source = BAT ]
    RA: 104.280141711717   Dec: 1.06112010114358  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 104.287878858126   Dec: 1.07707317468475  [deg; J2000]  
        { 06h 57m 09.1s , +01d 04' 37.5" }
         +/- 1.26344102968527 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.646465511332091 [arcmin] (formal 1-sigma fit error)
    SNR: 21.7790956575972
 
  Angular difference between the analysis and refined position is 1.063784 arcmin
 
  Partial Coding Fraction: 0.09667969    [ including projection effects ]

  Duration
     T90: 16.3040000200272 +/- 1.85082043762432
        Measured from: -10.9919999837875
                   to: 5.31200003623962     [s; relative to TRIGTIME]
     T50: 3.74400007724762 +/- 0.337520358679582
        Measured from: -2.32000005245209
                   to: 1.42400002479553     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.0839999914169312     
                   to: 1.08399999141693     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -14.6560000181198     
                   to: 8.95999991893768     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     4.404325   6.281653   3.976075   0.746969
           0.153715   0.174934   0.146219   0.107242 [error]
 Peak      0.598722   0.959388   0.735921   0.139273
           0.045953   0.057174   0.050093   0.029432 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   23.616  -14.656    8.960
T90    16.304  -10.992    5.312
T50     3.744   -2.320    1.424
Peak    1.000    0.084    1.084
 
 
====== 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: 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      -1.811    -0.062      0.062       -           -               -         4.52e-02     -1.64e-03          1.63e-03      62.560   57
CPL     -1.228    -0.266      0.282       67.697      -8.128        16.165      8.76e-02     -2.23e-02          3.22e-02      47.620   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      -1.672     -0.102     0.100       -           -               -         1.64e-01     -1.13e-02          1.13e-02      66.850   57
CPL     -0.540     -0.466     0.516       66.152      -7.824        13.308      6.11e-01     -2.51e-01          4.82e-01      47.600   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   1.83e-06  2.78e-06  3.17e-06  6.89e-06  9.82e-06  1.47e-05   erg/cm2
      90%_error_low -1.11e-07 -1.04e-07 -1.48e-07 -6.59e-07 -3.60e-07 -7.82e-07   erg/cm2
      90%_error_hi   1.13e-07  1.03e-07  1.47e-07  7.01e-07  3.61e-07  8.10e-07   erg/cm2
Peak flux       PL   7.95e+00  7.23e+00  4.54e+00  4.35e+00  2.15e+01  2.41e+01   ph/cm2/s
      90%_error_low -8.16e-01 -5.06e-01 -3.78e-01 -6.52e-01 -1.48e+00 -1.61e+00   ph/cm2/s
      90%_error_hi   8.37e-01  5.04e-01  3.75e-01  7.06e-01  1.48e+00  1.61e+00   ph/cm2/s
 
Fluence        CPL   1.63e-06  2.92e-06  3.30e-06  3.35e-06  9.50e-06  1.12e-05   erg/cm2
      90%_error_low -1.36e-07 -1.23e-07 -1.65e-07 -8.57e-07 -3.91e-07 -9.37e-07   erg/cm2
      90%_error_hi   1.38e-07  1.24e-07  1.67e-07  1.21e-06  3.91e-07  1.24e-06   erg/cm2
Peak flux      CPL   6.55e+00  8.16e+00  5.18e+00  1.76e+00  2.12e+01  2.16e+01   ph/cm2/s
      90%_error_low -9.71e-01 -6.42e-01 -4.80e-01 -5.48e-01 -1.50e+00 -1.60e+00   ph/cm2/s
      90%_error_hi   9.92e-01  6.55e-01  4.89e-01  7.52e-01  1.50e+00  1.63e+00   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  104.2879     1.0771   0.0088    43.9080   130.4633        16.5468550     21.779 TRIG_01212898                 
 
Foreground time interval of the image:
-14.656   8.960 (delta_t =  23.616 [sec])
Background time interval of the image:
-99.187 -14.656 (delta_t =  84.531 [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  -14.656 sec. to    8.960 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.81078     ( -0.0623897   0.0618978 )
Norm@50keV  : 4.51915E-02    ( -0.00163687   0.00163387 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   62.56     using 59 bins.
 Reduced chi-squared = 1.09754
# Null hypothesis probability of 2.86e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 23.62 sec: 6.25385 ( -0.24021  0.24087 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.82472e-06 ( -3.5995e-07  3.60727e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -14.656 sec. to    8.960 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.22809     ( -0.265637   0.281937 )
Epeak [keV] : 67.6972      ( -8.12842 16.1649 )
Norm@50keV  : 8.75511E-02    ( -0.0222998   0.0322389 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.62     using 59 bins.
 Reduced chi-squared = 0.850357
# Null hypothesis probability of 7.80e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 23.62 sec: 6.03942 ( -0.25598  0.25698 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.49708e-06 ( -3.91244e-07  3.90722e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.084 sec. to    1.084 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.6722     ( -0.10162   0.0998458 )
Norm@50keV  : 0.163778    ( -0.0113121   0.0112749 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   66.85     using 59 bins.
 Reduced chi-squared = 1.17281
# Null hypothesis probability of 1.75e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 21.5454 ( -1.4837  1.485 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.5202e-06 ( -1.08865e-07  1.09171e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.084 sec. to    1.084 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.539888     ( -0.466317   0.516287 )
Epeak [keV] : 66.1516      ( -7.82397 13.308 )
Norm@50keV  : 0.610899    ( -0.250532   0.482363 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.60     using 59 bins.
 Reduced chi-squared = 0.85
# Null hypothesis probability of 7.80e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 21.1589 ( -1.4968  1.4979 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.48754e-06 ( -1.1163e-07  1.11908e-07 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 16.304 sec.
Hardness ratio (energy fluence ratio) = 1.12898955709

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

S(15-50 keV)  = 4.55268e-06
S(50-150 keV) = 4.944448e-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 = -6.246842340291677E-01, IMY = -7.323611388375612E-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:
-99.187410 -14.656000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7410  22.0885    0.6  16.9  153.5   3.6714  19.4    7.5	Crab                          
101.2645   3.4215    2.9  40.4  132.8   2.0682   4.0 ------	UNKNOWN                       

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

Time interval of the image:
-14.656000 8.960000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6162  21.8654    7.6  17.1  154.1  -0.1840  -1.5    9.0	Crab                          
104.2879   1.0771    0.5  43.9  130.5  16.5535  21.2 ------	UNKNOWN                       
129.4704  40.8221    2.9  38.2   58.2   1.8150   4.0 ------	UNKNOWN                       
108.7048  13.2557    2.8  36.3  114.1   1.5824   4.1 ------	UNKNOWN                       
167.9879  74.4306    2.6  52.8    7.8   1.6620   4.5 ------	UNKNOWN                       
 34.5840  17.3217    2.9  44.2 -117.7   1.2929   4.0 ------	UNKNOWN                       
 32.5594  23.0644    2.5  42.4 -109.3   1.4309   4.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
123.812590 962.643200
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6324  22.0247    0.6  28.9  -15.3  32.5288  20.9    0.6	Crab                          
135.5177 -40.5552    1.1  50.5  175.9  43.8975  11.0    0.5	Vela X-1                      
130.1627  20.7151    3.3  32.1   77.3  11.3498   3.5 ------	UNKNOWN                       
113.5369  22.8569    3.7  23.6   48.9   5.4606   3.1 ------	UNKNOWN                       
 80.8218  51.4536    2.3  54.1    9.1  25.4807   4.9 ------	UNKNOWN