GRB170728A: 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: Tue Aug 15 14:38:47 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger765008
======================================================================

  Trigger: 00765008      Segment: 000

  BAT Trigger Time: 522917628.224   [s; MET]
      Trigger Stop: 522917629.248   [s; MET]
               UTC: 2017-07-28T06:53:28.786200    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 58.8977966424924   Dec: 12.1531504042179  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.37
     Image Trigger?:     NO
     Rate S/N Ratio:     13.6014705087354  [ if not an image trigger ]
     Image S/N Ratio:    8.37

  Analysis Position:   [ source = BAT ]
    RA: 58.8977966424924   Dec: 12.1531504042179  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 58.9019491881013   Dec: 12.1623143083089  [deg; J2000]  
        { 03h 55m 36.5s , +12d 09' 44.3" }
         +/- 2.13400162372094 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.13550854820716 [arcmin] (formal 1-sigma fit error)
    SNR: 10.3000699020161
 
  Angular difference between the analysis and refined position is 0.601366 arcmin
 
  Partial Coding Fraction: 0.734375    [ including projection effects ]

  Duration
     T90: 1.24799996614456 +/- 0.246868420778323
        Measured from: 0.236000001430511
                   to: 1.48399996757507     [s; relative to TRIGTIME]
     T50: 0.519999980926514 +/- 0.206155252368384
        Measured from: 0.61599999666214
                   to: 1.13599997758865     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.200000047683716     
                   to: 1.20000004768372     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.168000042438507     
                   to: 1.58400005102158     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.054699   0.076575   0.026221   0.000316
           0.008658   0.008987   0.007517   0.006220 [error]
 Peak      0.039421   0.063677   0.022043  -0.001261
           0.007381   0.007649   0.006431   0.005260 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    1.416    0.168    1.584
T90     1.248    0.236    1.484
T50     0.520    0.616    1.136
Peak    1.000    0.200    1.200
 
 
====== 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      -2.001    -0.271      0.249       -           -               -         6.33e-03     -1.26e-03          1.23e-03      65.120   57
CPL      0.997    -1.627      2.252       38.786      -5.490         7.075      3.98e-01     -3.98e-01          8.63e+00      52.860   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      -1.959     -0.289     0.265       -           -               -         7.26e-03     -1.51e-03          1.48e-03      76.490   57
CPL      1.148     -1.769     2.561       41.000      -5.970         7.654      4.69e-01     -4.69e-01          1.31e+01      65.630   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   1.84e-08  2.49e-08  2.49e-08  4.49e-08  8.27e-08  1.13e-07   erg/cm2
      90%_error_low -3.55e-09 -3.93e-09 -6.35e-09 -1.86e-08 -1.53e-08 -2.76e-08   erg/cm2
      90%_error_hi   3.63e-09  3.91e-09  6.62e-09  2.55e-08  1.58e-08  3.30e-08   erg/cm2
Peak flux       PL   4.65e-01  3.57e-01  1.84e-01  1.36e-01  1.07e+00  1.14e+00   ph/cm2/s
      90%_error_low -9.93e-02 -5.93e-02 -4.78e-02 -5.62e-02 -1.76e-01 -1.92e-01   ph/cm2/s
      90%_error_hi   1.03e-01  5.92e-02  4.92e-02  7.52e-02  1.76e-01  1.93e-01   ph/cm2/s
 
Fluence        CPL    N/A      N/A      N/A      N/A      N/A      N/A      erg/cm2
      90%_error_low -3.55e-09 -3.93e-09 -6.35e-09 -1.86e-08 -1.53e-08 -2.76e-08   erg/cm2
      90%_error_hi   3.63e-09  3.91e-09  6.62e-09  2.55e-08  1.58e-08  3.30e-08   erg/cm2
Peak flux      CPL   3.48e-01  4.89e-01  1.65e-01  7.07e-03  1.01e+00  1.01e+00   ph/cm2/s
      90%_error_low -1.27e-01 -9.15e-02 -6.17e-02 -7.07e-03 -1.76e-01 -1.76e-01   ph/cm2/s
      90%_error_hi   1.27e-01  9.38e-02  6.45e-02  2.80e-02  1.77e-01  1.77e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   58.9019    12.1623   0.0186    18.8817    97.8247         0.1721224     10.300 TRIG_00765008                 
 
Foreground time interval of the image:
  0.168   1.584 (delta_t =   1.416 [sec])
Background time interval of the image:
-437.923 -423.568 (delta_t =  14.355 [sec])
-239.224   0.168 (delta_t = 239.392 [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    0.168 sec. to    1.584 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.00086     ( -0.270601   0.249749 )
Norm@50keV  : 6.33064E-03    ( -0.00125668   0.00123409 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.12 using 59 PHA bins.
# Reduced chi-squared =          1.142 for     57 degrees of freedom 
# Null hypothesis probability =   2.150891e-01
 
Photon flux (15-150 keV)    in 1.416 sec: 0.950033 ( -0.146273  0.146287 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.26654e-08 ( -1.53051e-08  1.58045e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.168 sec. to    1.584 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.996732     ( -1.64204   2.23683 )
Epeak [keV] : 38.7865      ( -5.48576 7.07924 )
Norm@50keV  : 0.398283    ( -0.411097   8.6162 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.86 using 59 PHA bins.
# Reduced chi-squared =         0.9439 for     56 degrees of freedom 
# Null hypothesis probability =   5.944696e-01
 
Photon flux (15-150 keV)    in 1.416 sec: 0.906039 ( -0.143595  0.144501 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.200 sec. to    1.200 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.95892     ( -0.288917   0.265312 )
Norm@50keV  : 7.25660E-03    ( -0.00150994   0.00147758 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          76.49 using 59 PHA bins.
# Reduced chi-squared =          1.342 for     57 degrees of freedom 
# Null hypothesis probability =   4.342697e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.06851 ( -0.176192  0.17619 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.68021e-08 ( -1.31409e-08  1.35524e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.200 sec. to    1.200 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.14801     ( -1.78944   2.54084 )
Epeak [keV] : 40.9998      ( -5.97408 7.65019 )
Norm@50keV  : 0.468797    ( -0.48875   13.0433 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.63 using 59 PHA bins.
# Reduced chi-squared =          1.172 for     56 degrees of freedom 
# Null hypothesis probability =   1.774627e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.00874 ( -0.175932  0.17694 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 1.248 sec.
Hardness ratio (energy fluence ratio) = 0.999078913013

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

S(15-50 keV)  = 4.325833e-08
S(50-150 keV) = 3.940919e-08

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 = -4.656366700604371E-02, IMY = -3.388349521809715E-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:
-437.923400 -423.568400
-239.224000 0.168000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6283  22.0185    0.3   7.9 -120.7  10.4089  43.5    0.4	Crab                          
 25.5859  50.3755    2.6  53.9  158.9   6.4161   4.5 ------	UNKNOWN                       
 76.2174  13.1927    2.6   3.4   47.1   1.0090   4.5 ------	UNKNOWN                       
 45.7876  67.8781    3.1  55.7 -176.4   4.1560   3.8 ------	UNKNOWN                       
 99.4086   2.7084    2.3  25.0  -42.1   1.2963   5.0 ------	UNKNOWN                       
119.7114  41.2905    2.8  43.8 -116.1   4.4055   4.1 ------	UNKNOWN                       

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

Time interval of the image:
0.168000 1.584000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7787  22.0872  123.9   8.1 -120.3   0.0012   0.1    9.2	Crab                          
 33.4436  40.1600    2.4  45.3  148.7   0.1872   4.8 ------	UNKNOWN                       
 58.9020  12.1623    1.1  18.9   97.8   0.1721  10.3 ------	UNKNOWN                       
106.4313 -29.4789    2.1  53.3  -13.6   0.1975   5.5 ------	UNKNOWN                       
121.7572  -2.1977    2.6  47.0  -53.4   0.2366   4.5 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
54.876600 437.076600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6406  21.9983    0.4  25.6 -100.3  15.4359  32.1    1.1	Crab                          
 17.9730   7.0915    3.1  40.6  102.4   5.6553   3.7 ------	UNKNOWN                       
 63.3430   9.7226    4.1   5.0  -45.6   0.8995   2.8 ------	UNKNOWN                       
 91.0944  -4.2421    3.1  35.9  -49.1   2.2766   3.8 ------	UNKNOWN