GRB230805B: 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: Fri Sep 29 23:31:36 EDT 2023
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1183217
======================================================================

  Trigger: 01183217      Segment: 000

  BAT Trigger Time: 712927462.848   [s; MET]
      Trigger Stop: 712927471.04   [s; MET]
               UTC: 2023-08-05T11:23:51.076980    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 207.746617283295   Dec: 31.1848044696489  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.49
     Image Trigger?:     NO
     Rate S/N Ratio:     10.6301458127346  [ if not an image trigger ]
     Image S/N Ratio:    8.49

  Analysis Position:   [ source = BAT ]
    RA: 207.746617283295   Dec: 31.1848044696489  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 207.749701523998   Dec: 31.1945940784244  [deg; J2000]  
        { 13h 50m 59.9s , +31d 11' 40.5" }
         +/- 1.90434194074106 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.802160103944459 [arcmin] (formal 1-sigma fit error)
    SNR: 12.1194458449411
 
  Angular difference between the analysis and refined position is 0.608335 arcmin
 
  Partial Coding Fraction: 0.4179688    [ including projection effects ]

  Duration
     T90: 114.519999980927 +/- 23.3490886469143
        Measured from: -11.7520000934601
                   to: 102.767999887466     [s; relative to TRIGTIME]
     T50: 38.5359998941422 +/- 18.5921291415388
        Measured from: 6.74000000953674
                   to: 45.2759999036789     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -17.6640000343323     
                   to: -16.6640000343323     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -17.6560000181198     
                   to: 109.307999968529     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.707860   1.023557   0.854629   0.291424
           0.104043   0.109474   0.097939   0.085297 [error]
 Peak      0.008860   0.046508   0.069512   0.023300
           0.010280   0.011072   0.010953   0.008762 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  126.964  -17.656  109.308
T90   114.520  -11.752  102.768
T50    38.536    6.740   45.276
Peak    1.000  -17.664  -16.664
 
 
====== 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      -1.409    -0.195      0.197       -           -               -         1.55e-03     -1.75e-04          1.74e-04      53.780   57
CPL     -1.355    -0.406      0.656      612.785    -612.785      -612.785      1.65e-03     -2.69e-04          8.07e-05      53.820   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      -0.762     -0.337     0.379       -           -               -         1.03e-02     -2.49e-03          2.40e-03      52.720   57
CPL      0.473     -1.369     2.431      129.388     -46.711      -129.388      3.12e-02     -3.12e-02          1.85e-01      50.950   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   2.31e-07  4.48e-07  6.75e-07  2.20e-06  1.90e-06  3.56e-06   erg/cm2
      90%_error_low -4.65e-08 -5.66e-08 -9.37e-08 -6.00e-07 -2.30e-07 -6.74e-07   erg/cm2
      90%_error_hi   4.91e-08  5.57e-08  9.25e-08  7.38e-07  2.32e-07  7.84e-07   erg/cm2
Peak flux       PL   2.10e-01  3.29e-01  3.89e-01  8.88e-01  1.19e+00  1.82e+00   ph/cm2/s
      90%_error_low -9.25e-02 -1.02e-01 -7.91e-02 -3.17e-01 -2.67e-01 -3.88e-01   ph/cm2/s
      90%_error_hi   1.14e-01  1.03e-01  7.91e-02  4.19e-01  2.72e-01  4.08e-01   ph/cm2/s
 
Fluence        CPL   2.31e-07  4.48e-07  6.75e-07  2.21e-06  1.90e-06  3.35e-06   erg/cm2
      90%_error_low -4.78e-08 -5.57e-08 -9.27e-08 -1.39e-06 -2.48e-07 -1.18e-06   erg/cm2
      90%_error_hi   3.97e-08  6.58e-08  1.02e-07  3.87e-07  2.08e-07  1.49e-06   erg/cm2
Peak flux      CPL   1.37e-01  3.30e-01  4.54e-01  3.99e-01  1.15e+00  1.32e+00   ph/cm2/s
      90%_error_low -9.80e-02 -1.22e-01 -1.13e-01 -2.44e-01 -2.66e-01 -3.76e-01   ph/cm2/s
      90%_error_hi   1.41e-01  1.17e-01  1.18e-01  6.41e-01  2.75e-01  7.04e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  207.7497    31.1946   0.0158    43.5663     1.0423         2.8278250     12.119 TRIG_01183217                 
 
Foreground time interval of the image:
-17.656  75.253 (delta_t =  92.909 [sec])
Background time interval of the image:
-145.347 -17.656 (delta_t = 127.691 [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  -17.656 sec. to  109.308 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40922     ( -0.195135   0.19711 )
Norm@50keV  : 1.54992E-03    ( -0.000174666   0.000174445 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.78     using 59 bins.
 Reduced chi-squared = 0.943509
# Null hypothesis probability of 5.97e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 127 sec: 0.189153 ( -0.022342  0.022433 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.89869e-06 ( -2.30389e-07  2.31577e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -17.656 sec. to  109.308 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40627     ( -0.363678   0.698002 )
Epeak [keV] : 1.00000E+04      ( -10000 -10000 )
Norm@50keV  : 1.55546E-03    ( -0.000175307   0.000174552 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   53.78     using 59 bins.
 Reduced chi-squared = 0.960357
# Null hypothesis probability of 5.59e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 127 sec: 0.189223 ( -0.022641  0.022278 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.90039e-06 ( -2.4811e-07  2.07674e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from  -17.664 sec. to  -16.664 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.761752     ( -0.337054   0.379351 )
Norm@50keV  : 1.03131E-02    ( -0.00249088   0.0024009 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   52.72     using 59 bins.
 Reduced chi-squared = 0.924912
# Null hypothesis probability of 6.36e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.18727 ( -0.267346  0.27213 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.22512e-07 ( -2.52216e-08  2.52218e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -17.664 sec. to  -16.664 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.472855     ( -1.36682   2.43314 )
Epeak [keV] : 129.388      ( -46.8302 -129.507 )
Norm@50keV  : 3.11895E-02    ( -0.0311285   0.184972 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   50.95     using 59 bins.
 Reduced chi-squared = 0.909821
# Null hypothesis probability of 6.66e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 1.14629 ( -0.266159  0.27484 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.20687e-07 ( -2.65522e-08  2.59691e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 114.52 sec.
Hardness ratio (energy fluence ratio) = 1.50612137038

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

S(15-50 keV)  = 6.792811e-07
S(50-150 keV) = 1.2194071e-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 = 9.510104169653882E-01, IMY = -1.730260021096620E-02

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:
-145.347410 -17.656000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5288 -40.5544  109.5  54.6 -172.8   0.0664   0.1    0.0	Vela X-1                      
220.9644   2.8747    2.5  41.2   47.6   2.0408   4.6 ------	UNKNOWN                       
171.5085 -37.1512    3.2  34.5  158.6   1.1379   3.6 ------	UNKNOWN                       
212.5488  26.0468    3.4  43.1   10.7   1.2356   3.4 ------	UNKNOWN                       
132.0558  -6.4493    2.8  48.1 -129.2   4.1065   4.2 ------	UNKNOWN                       
158.7964  37.4014    2.7  45.7  -57.9   3.9425   4.3 ------	UNKNOWN                       

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

Time interval of the image:
-17.656000 75.252590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5210 -40.5696    7.4  54.6 -172.8   0.6397   1.6    1.0	Vela X-1                      
207.7497  31.1946    0.9  43.6    1.0   2.8275  12.1 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
174.652590 962.212000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3517  35.4243   10.9  38.8   64.8   3.0874   1.1    7.1	Her X-1                       
248.5952  14.7159    2.6  40.8   98.2  11.4091   4.4 ------	UNKNOWN                       
180.9168  39.8177    2.7  23.3  -67.1   4.6095   4.2 ------	UNKNOWN                       
169.1478  -0.0927    2.6  48.1 -129.2  19.6213   4.4 ------	UNKNOWN