batgrbproduct analysis for trigger=851855

batgrbproduct Analysis for Trigger=851855

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 (local 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

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

  Ground 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 Flight and Ground 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 ] 

======================================================================
 
=== 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   Power-law 7.13e-08 1.68e-07 3.19e-07 1.46e-06 8.63e-07 2.01e-06   erg/cm2
              Error 2.53e-08 3.54e-08 6.42e-08 6.97e-07 1.66e-07 7.29e-07   erg/cm2
Peak flux Power-law 3.10e-01 4.79e-01 5.55e-01 1.24e+00 1.71e+00 2.58e+00   ph/cm2/s
              Error 8.45e-02 8.11e-02 6.94e-02 3.30e-01 2.18e-01 3.60e-01   ph/cm2/s
 
Fluence   Cutoff-PL 7.15e-08 1.68e-07 3.17e-07 1.44e-06 8.65e-07 2.01e-06   erg/cm2
              Error -------- 3.35e-08 7.05e-08 -------- 1.73e-07 7.66e-07   erg/cm2
Peak flux Cutoff-PL 1.85e-01 4.80e-01 6.55e-01 4.49e-01 1.61e+00 1.77e+00   ph/cm2/s
              Error 1.08e-01 1.00e-01 1.00e-01 3.21e-01 2.34e-01 4.03e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s

 
=== Time-averaged spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.085    0.321    -      -           6.49e-04 1.14e-04   54.420 57
CPL   1.085    0.323    9999.4    0.0      6.52e-04 8.85e-04   54.430 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    0.786    0.211    -      -           1.49e-02 1.95e-03   57.830 57
CPL  -0.764    1.369     111.3   73.1      6.15e-02 1.05e-01   51.660 56
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^-{Ph_index} (minus sign is not included in the 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 PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedom

 
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
 
T90 in the 50-300 keV band: 123.200000 sec.
T50 in the 50-300 keV band: 54.080000 sec.

 
=== 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

Click here for the BAT GCN circular template

Special notes of this burst

Estimated redshift from machine learning (Ukwatta et al. 2016) - may take a few minute to calcaulte

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])

Lightcurves

Notes:

1) The mask-weighted light curves are using the flight position.
2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
5) Time of each bin is in the middle of the bin.

1 s binning

From T0-310 s to T0+310 s

From T100_start - 20 s to T100_end + 30 s

Full time interval

64 ms binning

Full time interval

From T100_start to T100_end

From T0-5 sec to T0+5 sec

16 ms binning

From T100_start-5 s to T100_start+5 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

8 ms binning

From T100_start-3 s to T100_start+3 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

2 ms binning

From T100_start-1 s to T100_start+1 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

SN=5 or 10 sec. binning (whichever binning is satisfied first)

SN=5 or 10 sec. binning (T < 200 sec)

Quad-rate summed light curves (from T0-300s to T0+1000s)

Spectral Evolution

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     ( -0.330275   0.311049 )
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     ( -0.335684   0.310154 )
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

Band function

Time interval is from   -0.100 sec. to  126.532 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 20.0665  (-4.54398  6.80574)
R^2/D10^2   : 3.42649E-03  (-0.00206061   0.00452178)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.06 using 59 PHA bins.
# Reduced chi-squared =          1.089 for     57 degrees of freedom 
# Null hypothesis probability =   3.005787e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.363e-08   1.348e-08
25- 50  1.679e-07   5.920e-08
50-150  5.013e-07   1.846e-07
15-150  7.029e-07   2.122e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-56.1154      -200)
Norm        : 0.309130       (-0.0556878     0.0556878)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.46 using 59 PHA bins.
# Reduced chi-squared =          1.061 for     57 degrees of freedom 
# Null hypothesis probability =   3.519139e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  9.750e-08   5.632e-08
25- 50  1.875e-07   1.061e-07
50-150  4.113e-07   2.355e-07
15-150  6.964e-07   4.002e-07

Double BB

------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.53 using 59 PHA bins.
#Fit statistic : Chi-Squared =          54.47 using 59 PHA bins.
#Fit statistic : Chi-Squared =          54.45 using 59 PHA bins.
#Fit statistic : Chi-Squared =          54.43 using 59 PHA bins.
# Reduced chi-squared =         0.9914 for     55 degrees of freedom 
# Reduced chi-squared =         0.9903 for     55 degrees of freedom 
# Reduced chi-squared =         0.9900 for     55 degrees of freedom 
# Reduced chi-squared =         0.9897 for     55 degrees of freedom 
# Null hypothesis probability =   4.925535e-01
# Null hypothesis probability =   4.949954e-01
# Null hypothesis probability =   4.956578e-01
# Null hypothesis probability =   4.961636e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  6.794e-08   4.119e-08
25- 50  1.790e-07   9.868e-08
50-150  6.168e-07   3.406e-07
15-150  8.637e-07   4.551e-07

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     ( -0.216181   0.205117 )
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     ( -1.61431   1.123 )
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

Band function

Time interval is from   -0.108 sec. to    0.892 sec.
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 25.1154  (-3.44869  4.44229)
R^2/D10^2   : 4.43938E-02  (-0.017265   0.0256828)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.98 using 59 PHA bins.
# Reduced chi-squared =         0.9119 for     57 degrees of freedom 
# Null hypothesis probability =   6.633855e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.853e-09   1.202e-09
25- 50  2.759e-08   6.650e-09
50-150  1.290e-07   2.634e-08
15-150  1.614e-07   2.985e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (-21.7067      -200)
Norm        : 6.72948       (-0.913888     0.913889)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          92.85 using 59 PHA bins.
# Reduced chi-squared =          1.629 for     57 degrees of freedom 
# Null hypothesis probability =   1.897687e-03
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.675e-08   9.360e-09
25- 50  3.222e-08   1.805e-08
50-150  7.066e-08   3.953e-08
15-150  1.196e-07   6.640e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 3.51671        (-3.32176      -3.32176)
R1^2/D10^2  : 6.74820        (-8.30631      -8.30631)
kT2 [keV]   : 26.2261        (-3.85465      -26.1062)
R2^2/D10^2  : 3.83064E-02    (-0.0388721   0.0243068)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.48 using 59 PHA bins.
# Reduced chi-squared =         0.9179 for     55 degrees of freedom 
# Null hypothesis probability =   6.476252e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  7.633e-09   3.074e-09
25- 50  2.669e-08   6.910e-09
50-150  1.310e-07   2.959e-08
15-150  1.654e-07   4.007e-08

Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)

Power-law model

 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.632131     ( -0.775274   0.617746 )
Norm@50keV  : 1.13668E-03    ( -0.000471067   0.000421466 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.58 using 59 PHA bins.
# Reduced chi-squared =         0.9575 for     57 degrees of freedom 
# Null hypothesis probability =   5.664855e-01
 
Photon flux (15-150 keV)    in 15.54 sec: 0.132225 ( -0.0452757  0.0466049 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.22472e-07 ( -7.13901e-08  7.17776e-08 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.619942     ( -0.916772   0.623793 )
Epeak [keV] : 9998.80      ( -9999.29 -9999.29 )
Norm@50keV  : 1.14308E-03    ( -0.000450881   0.0203936 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.58 using 59 PHA bins.
# Reduced chi-squared =         0.9746 for     56 degrees of freedom 
# Null hypothesis probability =   5.287688e-01
 
Photon flux (15-150 keV)    in 15.54 sec: 0.132436 ( -0.0460252  0.046263 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.22537e-07 ( -7.17707e-08  7.15633e-08 ) ergs/cm2

Band function

 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       :    (     )
beta        :     (     )
Epeak [keV] :       (   )
Norm@50keV   :     (     )
------------------------------------------------------------
 
Photon flux (15-150 keV)    in  sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

S(25-50 keV) vs. S(50-100 keV) plot

S(25-50 keV)  = 1.68e-07
S(50-100 keV) = 3.19e-07

T90 vs. Hardness ratio plot

T90                                   = 122.239999890327 sec.
Hardness ratio (energy fluence ratio) = 1.89881

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.21954
Count Ratio (50-100 keV) / (15-25 keV) = 1.26306

Mask shadow pattern

IMX = 4.067641114553334E-01, IMY = 3.681423310960769E-01

TIME vs. PHA plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

TIME vs. DetID plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

100 us light curve (15-350 keV)

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 0.256000

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

Plot creation:
Fri Oct 26 12:42:49 EDT 2018