GRB171120A: 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: Sat Jan 20 04:53:30 EST 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger791201
======================================================================

  Trigger: 00791201      Segment: 000

  BAT Trigger Time: 532876822.528   [s; MET]
      Trigger Stop: 532876822.784   [s; MET]
               UTC: 2017-11-20T13:20:02.497620    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 163.78729657664   Dec: 22.4495879527507  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    15.59
     Image Trigger?:     NO
     Rate S/N Ratio:     121.482509029078  [ if not an image trigger ]
     Image S/N Ratio:    15.59

  Analysis Position:   [ source = BAT ]
    RA: 163.78729657664   Dec: 22.4495879527507  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 163.774638463656   Dec: 22.4607281461912  [deg; J2000]  
        { 10h 55m 05.9s , +22d 27' 38.6" }
         +/- 1.2241508470428 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.559257194323208 [arcmin] (formal 1-sigma fit error)
    SNR: 22.7845207449016
 
  Angular difference between the analysis and refined position is 0.969247 arcmin
 
  Partial Coding Fraction: 0.1484375    [ including projection effects ]

  Duration
     T90: 64 +/- 16
        Measured from: -15.527999997139
                   to: 48.472000002861     [s; relative to TRIGTIME]
     T50: 32 +/- 16
        Measured from: 0.472000002861023
                   to: 32.472000002861     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 39.972000002861     
                   to: 40.972000002861     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -15.527999997139     
                   to: 64.472000002861     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     2.998048   4.580810   3.714740   1.071555
           0.129457   0.141077   0.127265   0.109066 [error]
 Peak      0.285227   0.438616   0.293792   0.066468
           0.012097   0.014240   0.012332   0.007959 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   80.000  -15.528   64.472
T90    64.000  -15.528   48.472
T50    32.000    0.472   32.472
Peak    1.000   39.972   40.972
 
 
====== 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: CPL)
 
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      -1.528    -0.064      0.064       -           -               -         1.10e-02     -3.93e-04          3.93e-04      62.800   57
CPL     -1.075    -0.260      0.276      111.630     -23.075        73.996      1.78e-02     -4.22e-03          5.92e-03      53.600   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: CPL)
 
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      -1.652     -0.068     0.068       -           -               -         7.15e-02     -2.92e-03          2.92e-03      58.060   57
CPL     -0.945     -0.301     0.324       75.372      -9.964        20.024      1.61e-01     -4.64e-02          7.17e-02      40.380   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   1.15e-06  2.08e-06  2.89e-06  8.35e-06  8.31e-06  1.45e-05   erg/cm2
      90%_error_low -7.68e-08 -8.37e-08 -1.27e-07 -7.88e-07 -3.13e-07 -8.72e-07   erg/cm2
      90%_error_hi   7.87e-08  8.34e-08  1.27e-07  8.39e-07  3.13e-07  9.12e-07   erg/cm2
Peak flux       PL   3.41e+00  3.13e+00  1.99e+00  1.95e+00  9.34e+00  1.05e+01   ph/cm2/s
      90%_error_low -2.31e-01 -1.34e-01 -1.01e-01 -1.91e-01 -3.91e-01 -4.17e-01   ph/cm2/s
      90%_error_hi   2.36e-01  1.34e-01  1.00e-01  2.03e-01  3.91e-01  4.17e-01   ph/cm2/s
 
Fluence        CPL   1.04e-06  2.15e-06  3.01e-06  4.80e-06  8.11e-06  1.10e-05   erg/cm2
      90%_error_low -9.70e-08 -9.34e-08 -1.46e-07 -1.21e-06 -3.36e-07 -1.25e-06   erg/cm2
      90%_error_hi   9.92e-08  9.42e-08  1.48e-07  1.73e-06  3.36e-07  1.73e-06   erg/cm2
Peak flux      CPL   2.98e+00  3.33e+00  2.12e+00  9.83e-01  9.04e+00  9.40e+00   ph/cm2/s
      90%_error_low -2.81e-01 -1.60e-01 -1.17e-01 -2.37e-01 -4.08e-01 -4.86e-01   ph/cm2/s
      90%_error_hi   2.87e-01  1.62e-01  1.18e-01  3.14e-01  4.08e-01  5.13e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  163.7746    22.4607   0.0085    55.1704   -10.6579         5.1845359     22.785 TRIG_00791201                 
 
Foreground time interval of the image:
-15.528   9.173 (delta_t =  24.701 [sec])
Background time interval of the image:
-239.528 -15.528 (delta_t = 224.000 [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  -15.528 sec. to   64.472 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.52763     ( -0.0638722   0.063741 )
Norm@50keV  : 1.09966E-02    ( -0.000393015   0.000392946 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.80 using 59 PHA bins.
# Reduced chi-squared =          1.102 for     57 degrees of freedom 
# Null hypothesis probability =   2.782439e-01
 
Photon flux (15-150 keV)    in 80 sec: 1.38330 ( -0.05361  0.05377 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.3104e-06 ( -3.12794e-07  3.13227e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -15.528 sec. to   64.472 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.07523     ( -0.259889   0.275825 )
Epeak [keV] : 111.630      ( -23.0752 73.9955 )
Norm@50keV  : 1.78340E-02    ( -0.0042207   0.00591566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.60 using 59 PHA bins.
# Reduced chi-squared =         0.9572 for     56 degrees of freedom 
# Null hypothesis probability =   5.661448e-01
 
Photon flux (15-150 keV)    in 80 sec: 1.34493 ( -0.0574  0.05767 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.10736e-06 ( -3.36484e-07  3.35702e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   39.972 sec. to   40.972 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.65234     ( -0.0681368   0.0676115 )
Norm@50keV  : 7.14941E-02    ( -0.00292308   0.00291766 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.06 using 59 PHA bins.
# Reduced chi-squared =          1.019 for     57 degrees of freedom 
# Null hypothesis probability =   4.358590e-01
 
Photon flux (15-150 keV)    in 1 sec: 9.34293 ( -0.39051  0.39112 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.6486e-07 ( -2.84749e-08  2.85498e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   39.972 sec. to   40.972 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.944906     ( -0.300518   0.323856 )
Epeak [keV] : 75.3723      ( -9.9638 20.0236 )
Norm@50keV  : 0.161494    ( -0.0464146   0.0716631 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.38 using 59 PHA bins.
# Reduced chi-squared =         0.7211 for     56 degrees of freedom 
# Null hypothesis probability =   9.425012e-01
 
Photon flux (15-150 keV)    in 1 sec: 9.04432 ( -0.40785  0.40847 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.37808e-07 ( -3.10856e-08  3.10132e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 64.0 sec.
Hardness ratio (energy fluence ratio) = 1.40019971457

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

S(15-50 keV)  = 3.188053e-06
S(50-150 keV) = 4.919328e-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 = 1.412432995485279E+00, IMY = 2.658084607445688E-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:
-239.528000 -15.528000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.2860  35.3400   10.1  39.5 -126.4  -0.5619  -1.1    8.4	Her X-1                       
299.5225  35.1340    7.5  55.8 -171.9   1.5522   1.5    5.2	Cyg X-1                       
308.1024  40.7979    6.5  53.8  177.6   1.6185   1.9    9.3	Cyg X-3                       
236.0431  30.1645    3.9  39.9 -101.0   2.9036   3.0 ------	UNKNOWN                       
212.9096  25.5452    3.1  42.5  -69.2   3.8316   3.8 ------	UNKNOWN                       
205.9654  23.6280    3.1  44.8  -60.2   4.5335   3.7 ------	UNKNOWN                       

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

Time interval of the image:
-15.528000 9.172600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4036  35.4460    4.9  39.4 -126.6  -0.3241  -2.4    6.8	Her X-1                       
299.6902  35.2388   43.3  55.8 -172.1  -0.0689  -0.3    5.4	Cyg X-1                       
308.0151  40.8947   94.1  53.7  177.6   0.0296   0.1    5.5	Cyg X-3                       
  9.5026  68.4967    2.5  42.3  121.7   1.1069   4.7 ------	UNKNOWN                       
163.7746  22.4607    0.5  55.2  -10.7   5.1846  22.8 ------	UNKNOWN                       
285.4934  34.6954    2.3  51.0 -158.8   0.8333   5.0 ------	UNKNOWN                       
183.3639  29.5875    2.8  42.7  -29.8   0.4268   4.1 ------	UNKNOWN                       
208.6797  31.5645    2.3  36.7  -63.0   0.6748   5.1 ------	UNKNOWN                       
252.2406  29.3507    2.0  44.5 -120.9   1.6155   5.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
77.572600 714.772590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
123.8424  19.4812    3.3  37.3   68.1   3.6513   3.5 ------	UNKNOWN                       
137.6255  68.3019    4.0  48.6  142.4   5.8572   2.9 ------	UNKNOWN                       
225.0062  61.6276    2.7  56.8 -175.2  10.0643   4.3 ------	UNKNOWN                       
219.8558  54.0524    2.8  52.3 -167.0   5.5185   4.1 ------	UNKNOWN                       
192.6018  29.7139    3.0  26.8 -136.9   1.7090   3.8 ------	UNKNOWN