GRB230216A: 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: Wed Jun 14 15:14:02 EDT 2023
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1154815
======================================================================

  Trigger: 01154815      Segment: 000

  BAT Trigger Time: 698251745.6   [s; MET]
      Trigger Stop: 698251747.648   [s; MET]
               UTC: 2023-02-16T14:48:34.830740    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 113.966019310163   Dec: -8.01514618542377  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.91
     Image Trigger?:     NO
     Rate S/N Ratio:     8.83176086632785  [ if not an image trigger ]
     Image S/N Ratio:    7.91

  Analysis Position:   [ source = BAT ]
    RA: 113.966019310163   Dec: -8.01514618542377  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 113.96596489547   Dec: -7.99355296059845  [deg; J2000]  
        { 07h 35m 51.8s , -07d 59' 36.8" }
         +/- 2.13159207191573 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.01772383349777 [arcmin] (formal 1-sigma fit error)
    SNR: 10.3167070725021
 
  Angular difference between the analysis and refined position is 1.295598 arcmin
 
  Partial Coding Fraction: 0.8515625    [ including projection effects ]

  Duration
     T90: 91.1999999284744 +/- 7.53924343521546
        Measured from: -78.8960000276566
                   to: 12.3039999008179     [s; relative to TRIGTIME]
     T50: 55.6159999370575 +/- 28.9156788765114
        Measured from: -55.0240000486374
                   to: 0.591999888420105     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.131999969482422     
                   to: 0.868000030517578     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -81.0720000267029     
                   to: 16.7839999198914     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.937724   0.896558   0.437592   0.037500
           0.099752   0.102789   0.089962   0.085937 [error]
 Peak      0.049420   0.073928   0.028941   0.000367
           0.011288   0.011900   0.010031   0.009239 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   97.856  -81.072   16.784
T90    91.200  -78.896   12.304
T50    55.616  -55.024    0.592
Peak    1.000   -0.132    0.868
 
 
====== 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      -1.918    -0.240      0.225       -           -               -         1.39e-03     -2.23e-04          2.18e-04      46.520   57
CPL     -1.334    -0.779      1.071       47.229     -45.854       -47.229      3.05e-03     -3.05e-03          9.68e-03      45.260   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      -1.911     -0.389     0.354       -           -               -         8.51e-03     -2.32e-03          2.25e-03      63.140   57
CPL     -0.550     -1.539     2.909       41.953     -41.953        78.477      5.64e-02     -5.64e-02          4.20e+00      60.950   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   2.58e-07  3.68e-07  3.90e-07  7.63e-07  1.25e-06  1.78e-06   erg/cm2
      90%_error_low -4.37e-08 -4.60e-08 -8.34e-08 -2.80e-07 -1.92e-07 -3.83e-07   erg/cm2
      90%_error_hi   4.47e-08  4.59e-08  8.58e-08  3.73e-07  1.98e-07  4.58e-07   erg/cm2
Peak flux       PL   5.21e-01  4.11e-01  2.19e-01  1.69e-01  1.23e+00  1.32e+00   ph/cm2/s
      90%_error_low -1.47e-01 -8.92e-02 -7.40e-02 -8.75e-02 -2.65e-01 -2.91e-01   ph/cm2/s
      90%_error_hi   1.53e-01  8.91e-02  7.68e-02  1.30e-01  2.65e-01  2.94e-01   ph/cm2/s
 
Fluence        CPL   2.47e-07  3.96e-07  3.78e-07  2.77e-07  1.18e-06  1.30e-06   erg/cm2
      90%_error_low -4.90e-08 -7.10e-08 -9.80e-08 -2.10e-07 -2.08e-07 -3.09e-07   erg/cm2
      90%_error_hi   4.84e-08  6.37e-08  9.37e-08  6.72e-07  2.27e-07  6.72e-07   erg/cm2
Peak flux      CPL   4.78e-01  4.87e-01  2.04e-01  3.11e-02  1.20e+00  1.20e+00   ph/cm2/s
      90%_error_low -1.65e-01 -1.22e-01 -1.15e-01 -3.11e-02 -2.64e-01 -2.68e-01   ph/cm2/s
      90%_error_hi   1.66e-01  1.40e-01  9.41e-02  1.78e-01  2.66e-01  2.82e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  113.9660    -7.9936   0.0187    15.9063    89.7704         2.4961010     10.317 TRIG_01154815                 
 
Foreground time interval of the image:
-81.072  16.784 (delta_t =  97.856 [sec])
Background time interval of the image:
-239.600 -81.072 (delta_t = 158.528 [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  -81.072 sec. to   16.784 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.91784     ( -0.239715   0.225357 )
Norm@50keV  : 1.39331E-03    ( -0.000223385   0.000217549 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   46.52     using 59 bins.
 Reduced chi-squared = 0.81614
# Null hypothesis probability of 8.38e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 97.86 sec: 0.201498 ( -0.024838  0.024838 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.25405e-06 ( -1.9224e-07  1.97983e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -81.072 sec. to   16.784 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.33441     ( -0.778934   1.071 )
Epeak [keV] : 47.2292      ( -45.8543 -47.2292 )
Norm@50keV  : 3.04777E-03    ( -0.0030478   0.00968434 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   45.26     using 59 bins.
 Reduced chi-squared = 0.808214
# Null hypothesis probability of 8.47e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 97.86 sec: 0.197352 ( -0.025479  0.025551 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.17656e-06 ( -2.08026e-07  2.2698e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.132 sec. to    0.868 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.91109     ( -0.389502   0.353413 )
Norm@50keV  : 8.51229E-03    ( -0.00232082   0.0022499 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   63.14     using 59 bins.
 Reduced chi-squared = 1.10772
# Null hypothesis probability of 2.68e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.22747 ( -0.264896  0.26491 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.82871e-08 ( -2.02641e-08  2.11595e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.132 sec. to    0.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.550152     ( -1.5399   2.90733 )
Epeak [keV] : 41.9529      ( -41.9417 78.488 )
Norm@50keV  : 5.64273E-02    ( -0.0565738   4.20011 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   60.95     using 59 bins.
 Reduced chi-squared = 1.08839
# Null hypothesis probability of 3.02e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.19643 ( -0.264396  0.26582 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.90542e-08 ( -1.99193e-08  2.32093e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 91.2 sec.
Hardness ratio (energy fluence ratio) = 1.05864409645

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

S(15-50 keV)  = 6.261054e-07
S(50-150 keV) = 6.279472e-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 = 1.141749730817181E-03, IMY = -2.849734827103940E-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:
-239.600000 -81.072000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6254  22.0298    0.9  43.9   14.0   6.2416  13.3    1.0	Crab                          
135.4708 -40.6720    4.1  36.8  173.0   1.4016   2.8    7.5	Vela X-1                      
138.2138   1.0800    2.0  41.0  104.0   6.4128   5.7 ------	UNKNOWN                       
124.0647 -69.1731    2.3  52.9 -151.8   4.7692   5.0 ------	UNKNOWN                       

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

Time interval of the image:
-81.072000 16.784000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6275  22.1202    5.5  43.9   14.0   0.8718   2.1    6.4	Crab                          
135.6180 -40.5044    7.3  36.8  172.7   0.4676   1.6    5.1	Vela X-1                      
113.9659  -7.9936    1.1  15.9   89.8   2.4963  10.3 ------	UNKNOWN                       
 93.4855  10.3446    2.5  29.6   22.2   1.2078   4.6 ------	UNKNOWN                       
148.0983 -55.0577    2.5  51.0 -174.3   2.4570   4.5 ------	UNKNOWN                       
 84.2404 -11.2161    2.8  18.0  -31.4   0.9204   4.1 ------	UNKNOWN                       
136.4612 -57.0511    2.5  46.7 -167.3   1.8101   4.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
82.900590 962.526800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6239  22.0147    0.8  42.3  -14.7  34.8150  14.2    0.5	Crab                          
135.5968 -40.5753    3.4  37.8 -177.7   8.3506   3.4    3.3	Vela X-1                      
163.5885 -29.9427    2.5  51.3  151.7  46.2118   4.6 ------	UNKNOWN