GRB230506B: 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 14:57:14 EDT 2023
             Host Name: batproc1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1167266
======================================================================

  Trigger: 01167266      Segment: 000

  BAT Trigger Time: 705069949.952   [s; MET]
      Trigger Stop: 705069950.08   [s; MET]
               UTC: 2023-05-06T12:45:18.718180    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 326.992980588766   Dec: 44.5403527391438  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.5
     Image Trigger?:     NO
     Rate S/N Ratio:     32.9241552663087  [ if not an image trigger ]
     Image S/N Ratio:    9.5

  Analysis Position:   [ source = BAT ]
    RA: 326.992980588766   Dec: 44.5403527391438  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 326.985868732122   Dec: 44.5141426681885  [deg; J2000]  
        { 21h 47m 56.6s , +44d 30' 50.9" }
         +/- 1.21574348727153 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.43333938036842 [arcmin] (formal 1-sigma fit error)
    SNR: 23.0099455937413
 
  Angular difference between the analysis and refined position is 1.601758 arcmin
 
  Partial Coding Fraction: 0.734375    [ including projection effects ]

  Duration
     T90: 61.539999961853 +/- 10.8925583836745
        Measured from: 2.62399995326996
                   to: 64.163999915123     [s; relative to TRIGTIME]
     T50: 21.5359998941422 +/- 3.96879016687736
        Measured from: 10.9919999837875
                   to: 32.5279998779297     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 10.6039999723434     
                   to: 11.6039999723434     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0239999294281006     
                   to: 76.2960000038147     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.209569   1.717474   1.312353   0.443115
           0.096711   0.095553   0.078766   0.067627 [error]
 Peak      0.131856   0.212727   0.195473   0.053052
           0.014822   0.016330   0.015639   0.012442 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   76.272    0.024   76.296
T90    61.540    2.624   64.164
T50    21.536   10.992   32.528
Peak    1.000   10.604   11.604
 
 
====== 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      -1.410    -0.112      0.113       -           -               -         3.96e-03     -2.37e-04          2.37e-04      39.430   57
CPL     -1.411    -0.109      0.201     9999.360    -9999.360      -9999.360      3.97e-03     -2.32e-04          1.28e-03      39.460   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      -1.276     -0.140     0.140       -           -               -         3.89e-02     -3.23e-03          3.22e-03      47.760   57
CPL     -0.790     -0.537     0.647      126.449     -46.241      -126.449      6.82e-02     -3.06e-02          7.29e-02      45.610   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   3.54e-07  6.88e-07  1.04e-06  3.38e-06  2.91e-06  5.45e-06   erg/cm2
      90%_error_low -4.04e-08 -4.63e-08 -7.87e-08 -5.48e-07 -1.91e-07 -6.01e-07   erg/cm2
      90%_error_hi   4.19e-08  4.60e-08  7.83e-08  6.22e-07  1.92e-07  6.61e-07   erg/cm2
Peak flux       PL   1.29e+00  1.49e+00  1.23e+00  1.70e+00  4.63e+00  5.71e+00   ph/cm2/s
      90%_error_low -1.84e-01 -1.34e-01 -1.25e-01 -3.32e-01 -3.81e-01 -4.99e-01   ph/cm2/s
      90%_error_hi   1.92e-01  1.33e-01  1.24e-01  3.79e-01  3.82e-01  5.07e-01   ph/cm2/s
 
Fluence        CPL   3.58e-07  6.84e-07  1.03e-06  3.54e-06  2.92e-06  5.28e-06   erg/cm2
      90%_error_low    N/A    -4.30e-08 -9.27e-08 -1.30e-06 -2.51e-07 -1.01e-06   erg/cm2
      90%_error_hi     N/A     5.01e-08  1.02e-07  1.17e-07  2.25e-07  8.14e-07   erg/cm2
Peak flux      CPL   1.18e+00  1.56e+00  1.28e+00  9.83e-01  4.54e+00  5.00e+00   ph/cm2/s
      90%_error_low -2.22e-01 -1.58e-01 -1.41e-01 -4.46e-01 -3.97e-01 -6.11e-01   ph/cm2/s
      90%_error_hi   2.28e-01  1.62e-01  1.44e-01  7.67e-01  3.95e-01  9.32e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  326.9859    44.5141   0.0083    16.6532   -87.6777         2.1131267     23.010 TRIG_01167266                 
 
Foreground time interval of the image:
  0.024  14.749 (delta_t =  14.725 [sec])
Background time interval of the image:
-239.952   0.024 (delta_t = 239.976 [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    0.024 sec. to   76.296 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.41004     ( -0.11228   0.112865 )
Norm@50keV  : 3.95849E-03    ( -0.000236793   0.000236557 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   39.43     using 59 bins.
 Reduced chi-squared = 0.691754
# Null hypothesis probability of 9.63e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 76.27 sec: 0.483189 ( -0.030355  0.030507 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.91174e-06 ( -1.90775e-07  1.91841e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.024 sec. to   76.296 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.4105     ( -0.109761   0.200775 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 3.96641E-03    ( -0.000236863   0.00127824 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   39.46     using 59 bins.
 Reduced chi-squared = 0.704643
# Null hypothesis probability of 9.54e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 76.27 sec: 0.485381 ( -0.032675  0.028199 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.92465e-06 ( -2.50943e-07  2.25156e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   10.604 sec. to   11.604 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.27607     ( -0.139969   0.139841 )
Norm@50keV  : 3.89356E-02    ( -0.00322736   0.00321635 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   47.76     using 59 bins.
 Reduced chi-squared = 0.837895
# Null hypothesis probability of 8.03e-01 with 57 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 4.62530 ( -0.38142  0.38161 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.87097e-07 ( -3.64582e-08  3.68289e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   10.604 sec. to   11.604 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.789672     ( -0.537227   0.647067 )
Epeak [keV] : 126.449      ( -46.2396 -126.447 )
Norm@50keV  : 6.82252E-02    ( -0.0306082   0.0729005 )
------------------------------------------------------------
#Fit statistic  : Chi-Squared                   45.61     using 59 bins.
 Reduced chi-squared = 0.814464
# Null hypothesis probability of 8.38e-01 with 56 degrees of freedom
 
Photon flux (15-150 keV)    in 1 sec: 4.53750 ( -0.39706  0.39498 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.72538e-07 ( -4.09109e-08  4.07093e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 61.54 sec.
Hardness ratio (energy fluence ratio) = 1.50525478112

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

S(15-50 keV)  = 1.0423435e-06
S(50-150 keV) = 1.8693884e-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 = 1.212068208750919E-02, IMY = 2.988785134397000E-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:
-239.952000 0.024000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4371  35.3663   39.9  40.1  126.3  -0.5644  -0.3    1.8	Her X-1                       
288.8377  10.9396    9.3  32.4   57.4  -1.0890  -1.2    2.3	GRS 1915+105                  
299.5911  35.1774    1.3   6.5   72.6   4.7822   9.1    1.5	Cyg X-1                       
308.1298  41.0187    3.2   2.4  -95.5   1.8530   3.7    4.1	Cyg X-3                       
326.3499  38.2062    6.1  16.3  -65.3   1.2268   1.9   10.9	Cyg X-2                       
299.4221  31.0375    2.5  10.0   56.7   2.3356   4.6 ------	UNKNOWN                       

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

Time interval of the image:
0.024000 14.748600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.5114  35.3919   35.0  40.0  126.3  -0.0632  -0.3    4.0	Her X-1                       
288.8190  10.8041    8.4  32.5   57.3   0.1605   1.4    8.6	GRS 1915+105                  
299.4056  35.1640   11.0   6.6   73.4   0.0813   1.1    9.3	Cyg X-1                       
307.8985  41.0451    4.8   2.3  -98.2   0.1807   2.4   11.1	Cyg X-3                       
326.0781  38.1546    4.2  16.1  -65.0   0.2453   2.7   11.0	Cyg X-2                       
326.9859  44.5141    0.5  16.7  -87.7   2.1132  23.0 ------	UNKNOWN                       
350.5887  58.5514    2.6  34.1 -112.7   0.7540   4.4 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
67.348600 962.200500
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5943  35.2086    1.4  22.8   78.3  15.9787   8.2    0.5	Cyg X-1                       
308.1898  40.9253    3.6  14.2   84.8   5.9732   3.2    4.0	Cyg X-3                       
326.1363  38.2360    5.9   6.3    8.9  -3.3918  -2.0    5.4	Cyg X-2                       
288.7819  32.8946    2.6  31.6   84.6  12.9418   4.4 ------	UNKNOWN                       
320.4158  -9.5274    2.4  54.4   10.9  21.6330   4.9 ------	UNKNOWN                       
352.8039  -5.6319    3.3  55.3  -29.0  23.7850   3.6  547.7	UNKNOWN                       
357.6471   4.1314    3.5  48.5  -39.9  16.4013   3.3  285.2	UNKNOWN