GRB180805B

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: Fri Oct 19 18:50:22 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger851855
======================================================================

  Trigger: 00851855      Segment: 000

  BAT Trigger Time: 555166977.856   [s; MET]
      Trigger Stop: 555166978.112   [s; MET]
               UTC: 2018-08-05T13:02:36.477100    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 25.8134664618429   Dec: -17.5033792589829  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.44
     Image Trigger?:     NO
     Rate S/N Ratio:     27.9821371592664  [ if not an image trigger ]
     Image S/N Ratio:    10.44

  Analysis Position:   [ source = BAT ]
    RA: 25.8134664618429   Dec: -17.5033792589829  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 25.8683304030413   Dec: -17.4813917776302  [deg; J2000]  
        { 01h 43m 28.4s , -17d 28' 53.0" }
         +/- 3.18066339331012 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.51010569104555 [arcmin] (formal 1-sigma fit error)
    SNR: 5.82419539117454
 
  Angular difference between the analysis and refined position is 3.405522 arcmin
 
  Partial Coding Fraction: 0.6796875    [ including projection effects ]

  Duration
     T90: 122.239999890327 +/- 18.0105578431205
        Measured from: 0.116000056266785
                   to: 122.355999946594     [s; relative to TRIGTIME]
     T50: 64.972000002861 +/- 32.5822332280177
        Measured from: 31.8880000114441
                   to: 96.8600000143051     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.107999920845032     
                   to: 0.892000079154968     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.0999999046325684     
                   to: 126.53200006485     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.311885   0.380356   0.393929   0.280514
           0.073273   0.076450   0.067945   0.061943 [error]
 Peak      0.033836   0.058124   0.096342   0.029780
           0.008145   0.009456   0.009015   0.007657 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  126.632   -0.100  126.532
T90   122.240    0.116  122.356
T50    64.972   31.888   96.860
Peak    1.000   -0.108    0.892
 
 
====== 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      -1.085    -0.311      0.330       -           -               -         6.49e-04     -1.14e-04          1.13e-04      54.420   57
CPL     -1.085    -0.309      0.337     9999.360    -9999.360      -9999.360      6.52e-04     -1.13e-04          1.66e-03      54.430   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      -0.786     -0.205     0.216       -           -               -         1.49e-02     -1.96e-03          1.93e-03      57.830   57
CPL      0.764     -1.123     1.615      111.252     -26.264       119.953      6.15e-02     -3.89e-02          1.71e-01      51.660   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   7.12e-08  1.69e-07  3.18e-07  1.45e-06  8.63e-07  2.01e-06   erg/cm2
      90%_error_low -2.40e-08 -3.61e-08 -6.48e-08 -5.73e-07 -1.65e-07 -6.22e-07   erg/cm2
      90%_error_hi   2.66e-08  3.48e-08  6.36e-08  8.20e-07  1.67e-07  8.36e-07   erg/cm2
Peak flux       PL   3.10e-01  4.79e-01  5.55e-01  1.24e+00  1.71e+00  2.58e+00   ph/cm2/s
      90%_error_low -8.00e-02 -8.14e-02 -6.95e-02 -3.00e-01 -2.18e-01 -3.51e-01   ph/cm2/s
      90%_error_hi   8.89e-02  8.07e-02  6.93e-02  3.60e-01  2.19e-01  3.70e-01   ph/cm2/s
 
Fluence        CPL   7.16e-08  1.68e-07  3.16e-07  1.44e-06  8.65e-07  2.02e-06   erg/cm2
      90%_error_low    N/A    -2.72e-08 -6.54e-08    N/A    -1.79e-07 -1.15e-06   erg/cm2
      90%_error_hi     N/A     3.98e-08  7.55e-08    N/A     1.67e-07  3.82e-07   erg/cm2
Peak flux      CPL   1.85e-01  4.80e-01  6.55e-01  4.49e-01  1.61e+00  1.77e+00   ph/cm2/s
      90%_error_low -9.77e-02 -1.03e-01 -9.83e-02 -2.10e-01 -2.35e-01 -3.28e-01   ph/cm2/s
      90%_error_hi   1.18e-01  9.70e-02  1.02e-01  4.32e-01  2.33e-01  4.78e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   25.8683   -17.4814   0.0330    28.7501   -42.1467         0.3396585      5.824 TRIG_00851855                 
 
Foreground time interval of the image:
 -0.100  15.445 (delta_t =  15.545 [sec])
Background time interval of the image:
-239.856  -0.100 (delta_t = 239.756 [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

Bokeh Plot

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   -0.100 sec. to  126.532 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.08548     ( -0.311049   0.330275 )
Norm@50keV  : 6.48936E-04    ( -0.000113679   0.000113388 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.42 using 59 PHA bins.
# Reduced chi-squared =         0.9548 for     57 degrees of freedom 
# Null hypothesis probability =   5.723494e-01
 
Photon flux (15-150 keV)    in 126.6 sec: 7.51699E-02 ( -0.0135163  0.0135796 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.63065e-07 ( -1.65293e-07  1.67354e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.100 sec. to  126.532 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.08468     ( -0.310154   0.335684 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 6.52062E-04    ( -0.000113513   0.00165585 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.43 using 59 PHA bins.
# Reduced chi-squared =         0.9719 for     56 degrees of freedom 
# Null hypothesis probability =   5.346306e-01
 
Photon flux (15-150 keV)    in 126.6 sec: 7.52970E-02 ( -0.0139106  0.0135709 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.64875e-07 ( -1.79302e-07  1.67063e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   -0.108 sec. to    0.892 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.785931     ( -0.205117   0.216181 )
Norm@50keV  : 1.48578E-02    ( -0.00195805   0.00193259 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.83 using 59 PHA bins.
# Reduced chi-squared =          1.015 for     57 degrees of freedom 
# Null hypothesis probability =   4.444942e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.70854 ( -0.218  0.21897 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.74679e-07 ( -2.24666e-08  2.25542e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.108 sec. to    0.892 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.763505     ( -1.123   1.61431 )
Epeak [keV] : 111.252      ( -26.2527 119.964 )
Norm@50keV  : 6.15484E-02    ( -0.0388905   0.170903 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.66 using 59 PHA bins.
# Reduced chi-squared =         0.9225 for     56 degrees of freedom 
# Null hypothesis probability =   6.396535e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.60611 ( -0.23475  0.23344 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.65863e-07 ( -2.45344e-08  2.42361e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 122.24 sec.
Hardness ratio (energy fluence ratio) = 1.88499415138

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

S(15-50 keV)  = 2.4017861e-07
S(50-150 keV) = 6.228993e-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 = 4.067641114553334E-01, IMY = 3.681423310960769E-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:
-239.856000 -0.100000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.2718  38.4038    5.2  52.1  161.8   2.3689   2.2    6.8	Cyg X-2                       
340.2847 -44.0150    3.1  44.8   36.5   2.2151   3.7 ------	UNKNOWN                       
  8.9877 -27.7380    2.4  26.0   -1.4   1.1075   4.8 ------	UNKNOWN

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

Time interval of the image:
-0.100000 15.444590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
326.1119  38.1971    5.7  52.0  161.5   0.4263   2.0    8.0	Cyg X-2                       
333.6822  -6.8009    2.1  27.0   96.7   0.3757   5.5 ------	UNKNOWN                       
 12.5695 -45.1981    2.0  43.5    3.5   0.4426   5.9 ------	UNKNOWN                       
 25.8683 -17.4814    2.0  28.8  -42.1   0.3398   5.8 ------	UNKNOWN                       
 47.2112 -26.3316    2.1  50.4  -41.9   1.1314   5.7 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
65.644590 962.184400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 34.8294 -38.9119    4.0  22.8   -6.9   1.7996   2.9 ------	UNKNOWN                       
 66.9446 -70.1167    3.7  58.2   -3.8  12.9879   3.1 ------	UNKNOWN                       
 71.3835 -68.8457    3.1  58.6   -6.1  13.6531   3.7 ------	UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

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

Post-slew image of 15-350 keV band

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