GRB160726A: 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 22 15:49:26 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger706052
======================================================================

  Trigger: 00706052      Segment: 000

  BAT Trigger Time: 491189664.288   [s; MET]
      Trigger Stop: 491189664.32   [s; MET]
               UTC: 2016-07-26T01:34:07.673500    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 98.8207862266102   Dec: -6.64457301434871  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.6
     Image Trigger?:     NO
     Rate S/N Ratio:     24.2899156029822  [ if not an image trigger ]
     Image S/N Ratio:    7.6

  Analysis Position:   [ source = BAT ]
    RA: 98.8207862266102   Dec: -6.64457301434871  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 98.8097713403672   Dec: -6.61705628207127  [deg; J2000]  
        { 06h 35m 14.3s , -06d 37' 01.4" }
         +/- 1.28567004748997 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.400102829777201 [arcmin] (formal 1-sigma fit error)
    SNR: 21.2431569048477
 
  Angular difference between the analysis and refined position is 1.776730 arcmin
 
  Partial Coding Fraction: 0.5859375    [ including projection effects ]

  Duration
     T90: 0.727999925613403 +/- 0.0430813282857434
        Measured from: 0.0160000324249268
                   to: 0.74399995803833     [s; relative to TRIGTIME]
     T50: 0.179999947547913 +/- 0.168760170863201
        Measured from: 0.495999991893768
                   to: 0.675999939441681     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.103999972343445     
                   to: 0.896000027656555     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.00400000810623169     
                   to: 0.787999987602234     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.070635   0.125319   0.133469   0.053616
           0.008490   0.010123   0.009806   0.007128 [error]
 Peak      0.075867   0.131073   0.138061   0.052557
           0.009349   0.010854   0.010349   0.007611 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    0.784    0.004    0.788
T90     0.728    0.016    0.744
T50     0.180    0.496    0.676
Peak    1.000   -0.104    0.896
 
 
====== 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: N/A)
 
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      -1.138    -0.136      0.138       -           -               -         3.35e-02     -2.69e-03          2.68e-03      57.990   57
CPL     -0.961    -0.247      0.532      333.080    -333.080      -333.080      4.04e-02     -9.15e-03          2.87e-02      57.600   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
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      -1.175     -0.139     0.141       -           -               -         2.72e-02     -2.25e-03          2.25e-03      63.030   57
CPL     -0.851     -0.391     0.582      200.510    -200.510      -200.510      3.83e-02     -1.27e-02          3.06e-02      61.900   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   2.39e-08  5.49e-08  9.98e-08  4.31e-07  2.72e-07  6.10e-07   erg/cm2
      90%_error_low -3.62e-09 -5.17e-09 -9.24e-09 -8.25e-08 -2.37e-08 -8.89e-08   erg/cm2
      90%_error_hi   3.79e-09  5.11e-09  9.16e-09  9.48e-08  2.38e-08  9.92e-08   erg/cm2
Peak flux       PL   8.21e-01  1.00e+00  8.89e-01  1.36e+00  3.19e+00  4.07e+00   ph/cm2/s
      90%_error_low -1.28e-01 -9.97e-02 -8.28e-02 -2.48e-01 -2.73e-01 -3.51e-01   ph/cm2/s
      90%_error_hi   1.35e-01  9.86e-02  8.21e-02  2.80e-01  2.73e-01  3.55e-01   ph/cm2/s
 
Fluence        CPL   2.30e-08  5.58e-08  1.02e-07  3.40e-07  2.70e-07  5.21e-07   erg/cm2
      90%_error_low -4.41e-09 -5.61e-09 -1.06e-08 -1.58e-07 -2.44e-08 -1.57e-07   erg/cm2
      90%_error_hi   3.79e-09  5.75e-09  1.11e-08  1.15e-07  2.43e-08  1.27e-07   erg/cm2
Peak flux      CPL   7.59e-01  1.03e+00  9.26e-01  9.87e-01  3.15e+00  3.70e+00   ph/cm2/s
      90%_error_low -1.59e-01 -1.07e-01 -1.01e-01 -3.85e-01 -2.79e-01 -4.88e-01   ph/cm2/s
      90%_error_hi   1.62e-01  1.09e-01  1.03e-01  4.53e-01  2.79e-01  5.77e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   98.8098    -6.6171   0.0091    38.0763   -26.0833         0.3905527     21.243 TRIG_00706052                 
 
Foreground time interval of the image:
  0.004   0.788 (delta_t =   0.784 [sec])
Background time interval of the image:
-239.288   0.004 (delta_t = 239.292 [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    0.004 sec. to    0.788 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.1381     ( -0.135857   0.137543 )
Norm@50keV  : 3.35173E-02    ( -0.00268748   0.002685 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.99 using 59 PHA bins.
# Reduced chi-squared =          1.017 for     57 degrees of freedom 
# Null hypothesis probability =   4.387337e-01
 
Photon flux (15-150 keV)    in 0.784 sec: 3.90340 ( -0.32275  0.32317 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.71516e-07 ( -2.36681e-08  2.37786e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.004 sec. to    0.788 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.960741     ( -0.246724   0.531645 )
Epeak [keV] : 333.080      ( -333.08 -333.08 )
Norm@50keV  : 4.04008E-02    ( -0.0091464   0.0286824 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.60 using 59 PHA bins.
# Reduced chi-squared =          1.029 for     56 degrees of freedom 
# Null hypothesis probability =   4.158373e-01
 
Photon flux (15-150 keV)    in 0.784 sec: 3.88145 ( -0.32833  0.32848 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.69828e-07 ( -2.44043e-08  2.42865e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.104 sec. to    0.896 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.175     ( -0.139434   0.140989 )
Norm@50keV  : 2.72276E-02    ( -0.00225133   0.00224993 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.03 using 59 PHA bins.
# Reduced chi-squared =          1.106 for     57 degrees of freedom 
# Null hypothesis probability =   2.715878e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.18519 ( -0.27267  0.27311 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.78253e-07 ( -2.49269e-08  2.50523e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.104 sec. to    0.896 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.850843     ( -0.391086   0.58184 )
Epeak [keV] : 200.510      ( -200.51 -200.51 )
Norm@50keV  : 3.83119E-02    ( -0.012652   0.0305909 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.90 using 59 PHA bins.
# Reduced chi-squared =          1.105 for     56 degrees of freedom 
# Null hypothesis probability =   2.736216e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.14952 ( -0.27895  0.27909 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.74897e-07 ( -2.59425e-08  2.58006e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 0.7279999 sec.
Hardness ratio (energy fluence ratio) = 1.81748232892

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

S(15-50 keV)  = 7.885578e-08
S(50-150 keV) = 1.9266447e-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 = 7.036455956279711E-01, IMY = 3.444578927201825E-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:
-239.288000 0.004000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6261  22.0179    0.2  10.7  -77.0   9.8473  48.0    0.4	Crab                          
 39.1429  35.9405    2.2  32.4  144.6   1.6249   5.2 ------	UNKNOWN                       
 19.5494  67.9833    3.3  56.9  179.3   4.3130   3.5 ------	UNKNOWN                       
100.1169  61.6554    2.7  44.9 -141.6   2.1659   4.3 ------	UNKNOWN                       
116.9649   3.4875    3.7  46.9  -54.2   3.3593   3.1 ------	UNKNOWN                       

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

Time interval of the image:
0.004000 0.788000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6459  21.8643    5.7  10.7  -76.2   0.0260   2.0    9.0	Crab                          
 70.1698 -25.9052    2.4  47.0   22.6   0.1473   4.7 ------	UNKNOWN                       
 98.8098  -6.6170    0.5  38.1  -26.1   0.3906  21.3 ------	UNKNOWN                       
104.3029  17.7719    2.7  30.4  -69.3   0.0858   4.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
188.412600 456.012590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5442 -40.5596    1.1  23.0 -103.7   3.0344  11.0    0.8	Vela X-1                      
170.5139 -60.6896    4.3   8.0   32.6   0.6325   2.7    7.1	Cen X-3                       
186.6796 -62.7655    0.6  15.4   46.9   4.4230  19.2    0.7	GX 301-2                      
204.7187 -33.9688    2.8  41.8    8.5   1.4776   4.1 ------	UNKNOWN                       
199.7751 -17.2419    2.9  54.1   -8.0   2.7123   4.0 ------	UNKNOWN                       
172.7465 -10.3283    2.7  52.1  -42.0   5.5706   4.3 ------	UNKNOWN