GRB170807A: 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 v2.46
    Process Start Time: Mon Aug 28 18:08:17 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger766821
======================================================================

  Trigger: 00766821      Segment: 000

  BAT Trigger Time: 523835788.608   [s; MET]
      Trigger Stop: 523835789.12   [s; MET]
               UTC: 2017-08-07T21:56:09.115840    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 143.379449689179   Dec: -17.3293730191527  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.17
     Image Trigger?:     NO
     Rate S/N Ratio:     14.247806848775  [ if not an image trigger ]
     Image S/N Ratio:    7.17

  Analysis Position:   [ source = BAT ]
    RA: 143.379449689179   Dec: -17.3293730191527  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 143.433398615419   Dec: -17.3478077800731  [deg; J2000]  
        { 09h 33m 44.0s , -17d 20' 52.1" }
         +/- 1.52125162759394 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.652205832713866 [arcmin] (formal 1-sigma fit error)
    SNR: 16.704410627956
 
  Angular difference between the analysis and refined position is 3.281859 arcmin
 
  Partial Coding Fraction: 0.921875    [ including projection effects ]

  Duration
     T90: 36.323999941349 +/- 7.97291137847716
        Measured from: 0.164000034332275
                   to: 36.4879999756813     [s; relative to TRIGTIME]
     T50: 28.4119999408722 +/- 7.53834567873316
        Measured from: 1.9200000166893
                   to: 30.3319999575615     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.700000047683716     
                   to: 1.70000004768372     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.435999989509583     
                   to: 52.2319999933243     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.515886   0.638487   0.340486   0.042848
           0.043118   0.043779   0.037046   0.031474 [error]
 Peak      0.054651   0.070699   0.051889   0.015181
           0.006725   0.007077   0.006197   0.004729 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   52.668   -0.436   52.232
T90    36.324    0.164   36.488
T50    28.412    1.920   30.332
Peak    1.000    0.700    1.700
 
 
====== 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      -1.816    -0.150      0.145       -           -               -         1.74e-03     -1.66e-04          1.64e-04      65.680   57
CPL     -0.983    -0.631      0.755       52.678      -9.961        33.967      5.12e-03     -2.82e-03          8.55e-03      60.350   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      -1.496     -0.189     0.187       -           -               -         1.17e-02     -1.34e-03          1.32e-03      61.020   57
CPL     -1.380     -0.723     0.685      246.342    -246.342      -246.342      1.34e-02     -5.60e-03          1.68e-02      60.920   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   1.58e-07  2.39e-07  2.71e-07  5.87e-07  8.43e-07  1.26e-06   erg/cm2
      90%_error_low -1.89e-08 -1.94e-08 -3.49e-08 -1.40e-07 -8.10e-08 -1.78e-07   erg/cm2
      90%_error_hi   1.94e-08  1.95e-08  3.53e-08  1.66e-07  8.24e-08  1.98e-07   erg/cm2
Peak flux       PL   4.79e-01  4.83e-01  3.43e-01  3.87e-01  1.46e+00  1.69e+00   ph/cm2/s
      90%_error_low -8.43e-02 -5.49e-02 -4.98e-02 -1.03e-01 -1.59e-01 -1.89e-01   ph/cm2/s
      90%_error_hi   8.78e-02  5.45e-02  4.93e-02  1.23e-01  1.59e-01  1.91e-01   ph/cm2/s
 
Fluence        CPL   1.45e-07  2.63e-07  2.65e-07  1.64e-07  7.75e-07  8.37e-07   erg/cm2
      90%_error_low -2.17e-08 -2.64e-08 -4.20e-08 -9.79e-08 -9.14e-08 -1.36e-07   erg/cm2
      90%_error_hi   2.18e-08  2.74e-08  4.00e-08  2.47e-07  9.53e-08  2.59e-07   erg/cm2
Peak flux      CPL   4.71e-01  4.90e-01  3.46e-01  3.30e-01  1.45e+00  1.64e+00   ph/cm2/s
      90%_error_low -9.44e-02 -6.00e-02 -5.18e-02 -1.85e-01 -1.61e-01 -2.53e-01   ph/cm2/s
      90%_error_hi   8.06e-02  6.61e-02  5.35e-02  7.22e-02  1.61e-01  2.34e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  143.4334   -17.3478   0.0116    14.2808  -116.5428         1.4928568     16.704 TRIG_00766821                 
 
Foreground time interval of the image:
 -0.436  52.232 (delta_t =  52.668 [sec])
Background time interval of the image:
-213.907  -0.436 (delta_t = 213.471 [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   -0.436 sec. to   52.232 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.81609     ( -0.149863   0.145432 )
Norm@50keV  : 1.73976E-03    ( -0.000166159   0.000163875 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.68 using 59 PHA bins.
# Reduced chi-squared =          1.152 for     57 degrees of freedom 
# Null hypothesis probability =   2.014012e-01
 
Photon flux (15-150 keV)    in 52.67 sec: 0.241260 ( -0.019775  0.019782 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.43284e-07 ( -8.10407e-08  8.2359e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.436 sec. to   52.232 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.983158     ( -0.631421   0.7553 )
Epeak [keV] : 52.6785      ( -9.96112 33.9666 )
Norm@50keV  : 5.11702E-03    ( -0.00281918   0.0085548 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.35 using 59 PHA bins.
# Reduced chi-squared =          1.078 for     56 degrees of freedom 
# Null hypothesis probability =   3.213758e-01
 
Photon flux (15-150 keV)    in 52.67 sec: 0.233034 ( -0.020654  0.020669 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.74665e-07 ( -9.14093e-08  9.53032e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.700 sec. to    1.700 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.49564     ( -0.189272   0.186697 )
Norm@50keV  : 1.16832E-02    ( -0.00133545   0.00132233 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.02 using 59 PHA bins.
# Reduced chi-squared =          1.070 for     57 degrees of freedom 
# Null hypothesis probability =   3.336298e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.45686 ( -0.15888  0.15895 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.10928e-07 ( -1.39574e-08  1.41238e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.700 sec. to    1.700 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.37992     ( -0.72615   0.68182 )
Epeak [keV] : 246.342      ( -255.185 -255.185 )
Norm@50keV  : 1.34492E-02    ( -0.00563135   0.0167295 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.92 using 59 PHA bins.
# Reduced chi-squared =          1.088 for     56 degrees of freedom 
# Null hypothesis probability =   3.034442e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.45125 ( -0.16148  0.16129 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.09845e-07 ( -1.51995e-08  1.48819e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 36.324 sec.
Hardness ratio (energy fluence ratio) = 1.13600415296

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

S(15-50 keV)  = 3.964173e-07
S(50-150 keV) = 4.468749e-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 = -1.137452022111278E-01, IMY = 2.277110940537140E-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:
-213.907410 -0.436000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5430 -40.5565    0.6  17.8  145.6   3.3177  17.8    0.7	Vela X-1                      
170.3630 -60.4518   83.6  33.6   83.9   0.0605   0.1   10.4	Cen X-3                       
186.8204 -62.8803    5.5  40.4   76.5   1.6717   2.1    8.0	GX 301-2                      
152.4332 -58.3270    0.9  29.2   99.8   3.6848  12.8 ------	UNKNOWN                       
209.1529 -29.8116    2.4  49.0   25.7   2.8529   4.9 ------	UNKNOWN                       
 89.3656 -37.2334    2.8  52.3  163.6   3.5164   4.1 ------	UNKNOWN                       
105.5963 -41.3788    2.7  39.5  159.1   1.5988   4.4 ------	UNKNOWN                       
121.0629  -9.5597    2.3  35.2 -142.6   1.3931   5.0 ------	UNKNOWN                       
198.1126   9.8616    3.7  58.9  -24.4   4.5083   3.2 ------	UNKNOWN                       
158.2470   7.4919    3.1  37.0  -70.2   1.8803   3.7 ------	UNKNOWN                       
183.2309  11.6929    3.3  50.6  -39.3   3.0481   3.5 ------	UNKNOWN                       

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

Time interval of the image:
-0.436000 52.232000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5716 -40.5809    1.8  17.8  145.5  -0.5858  -6.5    2.5	Vela X-1                      
170.2789 -60.7953  296.0  33.9   84.3   0.0072   0.0   10.4	Cen X-3                       
186.7110 -62.7173    3.3  40.3   76.4   1.3116   3.5    3.5	GX 301-2                      
154.1844 -65.4942    2.0  36.4   98.7   1.1931   5.8 ------	UNKNOWN                       
143.4334 -17.3478    0.7  14.3 -116.5   1.4925  16.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
410.892600 962.457200
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
170.3158 -60.6230  260.1  53.6  166.2  -0.0781  -0.0    0.0	Cen X-3                       
186.5203 -62.7027    6.0  52.6  156.3   4.0665   1.9    5.5	GX 301-2                      
231.1090 -34.9538    2.0  39.9  103.9   8.2444   5.8 ------	UNKNOWN                       
241.5568  16.5492    3.3  52.3   30.0   7.1780   3.5 ------	UNKNOWN                       
228.9724  -3.2052    3.3  33.2   50.2   2.1302   3.5 ------	UNKNOWN                       
182.0392 -56.2373    3.0  47.0  161.5   4.2363   3.8 ------	UNKNOWN                       
184.9997 -42.1812    2.3  33.2  166.1   2.7531   5.0 ------	UNKNOWN                       
227.1448  40.3490    3.3  58.3   -2.1   8.3014   3.5 ------	UNKNOWN                       
195.1417  34.4860    3.8  45.0  -30.8   2.0316   3.1 ------	UNKNOWN                       
146.2155 -16.0878    3.3  49.0 -131.6   6.7067   3.5 ------	UNKNOWN