GRB170724A: 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 14:48:25 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger764204
======================================================================

  Trigger: 00764204      Segment: 000

  BAT Trigger Time: 522550144   [s; MET]
      Trigger Stop: 522550208   [s; MET]
               UTC: 2017-07-24T00:48:44.583880    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 150.081345377704   Dec: -1.04756718482438  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.43
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    8.43

  Analysis Position:   [ source = BAT ]
    RA: 150.081345377704   Dec: -1.04756718482438  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 150.059986745671   Dec: -1.02641211043445  [deg; J2000]  
        { 10h 00m 14.4s , -01d 01' 35.1" }
         +/- 2.3714513329908 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.943849677733481 [arcmin] (formal 1-sigma fit error)
    SNR: 8.85898130146444
 
  Angular difference between the analysis and refined position is 1.803575 arcmin
 
  Partial Coding Fraction: 0.5859375    [ including projection effects ]

  Duration
     T90: 98.9799999594688 +/- 20.7571577896258
        Measured from: -39.7680000066757
                   to: 59.2119999527931     [s; relative to TRIGTIME]
     T50: 43.8759999275208 +/- 21.2041981897892
        Measured from: 4.90799999237061
                   to: 48.7839999198914     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 35.9160000085831     
                   to: 36.9160000085831     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -45.6439999938011     
                   to: 63.6039999723434     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.492392   0.586664   0.498023   0.195087
           0.072252   0.075177   0.065906   0.057768 [error]
 Peak      0.025161   0.014238   0.018288   0.012139
           0.006775   0.007269   0.006504   0.005588 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  109.248  -45.644   63.604
T90    98.980  -39.768   59.212
T50    43.876    4.908   48.784
Peak    1.000   35.916   36.916
 
 
====== 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      -1.466    -0.235      0.232       -           -               -         1.03e-03     -1.35e-04          1.34e-04      49.590   57
CPL     -1.467    -0.233      0.420     9999.360    -9999.360      -9999.360      1.03e-03     -1.03e-03          1.33e-03      49.590   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      -2.431     -1.186     0.839       -           -               -         2.44e-03     -1.66e-03          1.74e-03      60.650   57
CPL     -1.977      N/A       N/A           2.980      N/A           N/A         4.10e-03        N/A               N/A         61.170   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   1.40e-07  2.62e-07  3.79e-07  1.17e-06  1.08e-06  1.95e-06   erg/cm2
      90%_error_low -3.01e-08 -3.48e-08 -6.60e-08 -3.87e-07 -1.56e-07 -4.45e-07   erg/cm2
      90%_error_hi   3.18e-08  3.44e-08  6.52e-08  5.02e-07  1.58e-07  5.41e-07   erg/cm2
Peak flux       PL   2.48e-01  1.45e-01  5.37e-02  2.64e-02  4.60e-01  4.73e-01   ph/cm2/s
      90%_error_low -1.09e-01 -7.08e-02 -4.10e-02 -2.64e-02 -1.68e-01 -1.77e-01   ph/cm2/s
      90%_error_hi   1.07e-01  6.13e-02  5.81e-02  8.16e-02  1.68e-01  1.84e-01   ph/cm2/s
 
Fluence        CPL   1.41e-07  2.60e-07  3.77e-07  1.23e-06  1.08e-06  1.90e-06   erg/cm2
      90%_error_low -3.58e-08 -3.56e-08 -6.88e-08    N/A    -1.77e-07 -7.13e-07   erg/cm2
      90%_error_hi   3.26e-08  4.20e-08  7.26e-08    N/A     1.66e-07  5.69e-07   erg/cm2
Peak flux      CPL   2.28e-01  9.21e-02  2.31e-02  8.44e-03  3.48e-01  3.50e-01   ph/cm2/s
      90%_error_low -1.13e-01 -9.21e-02     N/A   -8.44e-03     N/A       N/A     ph/cm2/s
      90%_error_hi   1.14e-01  1.06e-01     N/A    8.08e-02     N/A       N/A     ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  150.0600    -1.0264   0.0217    25.1525   -69.9172         1.7298344      8.859 TRIG_00764204                 
 
Foreground time interval of the image:
-45.644  63.604 (delta_t = 109.248 [sec])
Background time interval of the image:
-142.099 -45.644 (delta_t =  96.455 [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  -45.644 sec. to   63.604 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.46589     ( -0.235261   0.232317 )
Norm@50keV  : 1.03374E-03    ( -0.000135119   0.000133781 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.59 using 59 PHA bins.
# Reduced chi-squared =         0.8699 for     57 degrees of freedom 
# Null hypothesis probability =   7.466256e-01
 
Photon flux (15-150 keV)    in 109.2 sec: 0.127907 ( -0.01633  0.016371 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.07729e-06 ( -1.56305e-07  1.58409e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -45.644 sec. to   63.604 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.46663     ( -0.233425   0.41941 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 1.03494E-03    ( -0.00103655   0.00132983 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.59 using 59 PHA bins.
# Reduced chi-squared =         0.8855 for     56 degrees of freedom 
# Null hypothesis probability =   7.145532e-01
 
Photon flux (15-150 keV)    in 109.2 sec: 0.128449 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.08219e-06 ( -1.76991e-07  1.66152e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   35.916 sec. to   36.916 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.43134     ( -1.18602   0.839175 )
Norm@50keV  : 2.44186E-03    ( -0.00165887   0.00174075 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.65 using 59 PHA bins.
# Reduced chi-squared =          1.064 for     57 degrees of freedom 
# Null hypothesis probability =   3.457547e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.460283 ( -0.167721  0.168181 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.39988e-08 ( -1.16763e-08  1.44648e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   35.916 sec. to   36.916 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 5.55447     (       )
Epeak [keV] : 22.1472      (   )
Norm@50keV  : 4385.81    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.56 using 59 PHA bins.
# Reduced chi-squared =          1.081 for     56 degrees of freedom 
# Null hypothesis probability =   3.148384e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.347527 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 98.98 sec.
Hardness ratio (energy fluence ratio) = 1.44813854156

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

S(15-50 keV)  = 4.015335e-07
S(50-150 keV) = 6.757476e-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 = 1.612335672968598E-01, IMY = 4.410025128998756E-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:
-142.099400 -45.644000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5591 -40.4085    6.0  19.0  149.6   0.2146   1.9    8.9	Vela X-1                      
170.1587 -60.7203    4.2  37.0   96.1   0.8786   2.7    7.4	Cen X-3                       
144.4993 -60.9050    2.3  35.0  117.1   1.1654   5.1 ------	UNKNOWN                       
102.7455  -2.8001    2.9  51.6 -139.6   2.3821   4.0 ------	UNKNOWN                       

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

Time interval of the image:
-45.644000 63.604000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.4632 -40.5162   40.9  19.2  149.5  -0.0461  -0.3    3.8	Vela X-1                      
170.1661 -60.7250    7.8  37.0   96.1  -0.6214  -1.5    7.5	Cen X-3                       
176.2876 -35.0278    2.1  23.6   50.0   0.9103   5.6 ------	UNKNOWN                       
191.7959   0.9200    2.3  47.9   -6.1   1.4430   5.0 ------	UNKNOWN                       
101.3289 -24.3953    2.4  44.5 -167.2   1.2954   4.8 ------	UNKNOWN                       
150.0600  -1.0264    1.3  25.2  -69.9   1.7294   8.9 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
721.400610 963.099800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.3187 -40.4508   13.7  22.0  -75.1  -0.2177  -0.8   11.4	Vela X-1                      
170.2590 -60.6507    2.3  14.8   30.1   1.0831   5.0    2.4	Cen X-3                       
186.3927 -62.6959   63.8  21.4   44.7  -0.0381  -0.2    8.5	GX 301-2                      
 11.4846 -66.0316    3.1  46.0  139.1   2.9158   3.7 ------	UNKNOWN                       
212.4530 -33.8200    2.7  52.9   26.0   4.6353   4.3 ------	UNKNOWN