batgrbproduct analysis for trigger=831816

batgrbproduct Analysis for Trigger=831816

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): Thu May 31 13:23:52 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger831816
======================================================================

  Trigger: 00831816      Segment: 000

  BAT Trigger Time: 547676163.2   [s; MET]
      Trigger Stop: 547676167.296   [s; MET]
               UTC: 2018-05-10T20:15:42.277740    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 77.9887913665582   Dec: -62.3350422840413  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.44
     Image Trigger?:     NO
     Rate S/N Ratio:     9.64365076099295  [ if not an image trigger ]
     Image S/N Ratio:    9.44

  Flight Position:   [ source = BAT ]
    RA: 77.9887913665582   Dec: -62.3350422840413  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 77.9617891654031   Dec: -62.3194091474247  [deg; J2000]  
        { 05h 11m 50.8s , -62d 19' 09.9" }
         +/- 1.67525278281714 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.627700451976007 [arcmin] (formal 1-sigma fit error)
    SNR: 14.5547113561785
 
  Angular difference between Flight and Ground position is 1.202482 arcmin
 
  Partial Coding Fraction: 0.4101562    [ including projection effects ]

  Duration
     T90: 134.016000032425 +/- 52.9225468980937
        Measured from: -13.1680001020432
                   to: 120.847999930382     [s; relative to TRIGTIME]
     T50: 28.8639999628067 +/- 7.80978659114986
        Measured from: 0.991999983787537
                   to: 29.8559999465942     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.96399998664856     
                   to: 1.96399998664856     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -19.9200000762939     
                   to: 137.103999972343     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.355591   1.686391   0.775132   0.207374
           0.121460   0.123199   0.103869   0.088842 [error]
 Peak      0.040811   0.059284   0.044886  -0.002253
           0.010340   0.010709   0.009052   0.007472 [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 4.77e-07 6.42e-07 6.36e-07 1.13e-06 2.12e-06 2.89e-06   erg/cm2
              Error 6.19e-08 5.79e-08 9.93e-08 3.51e-07 2.28e-07 4.58e-07   erg/cm2
Peak flux Power-law 4.47e-01 4.09e-01 2.58e-01 2.49e-01 1.22e+00 1.36e+00   ph/cm2/s
              Error 1.43e-01 8.50e-02 7.20e-02 1.38e-01 2.50e-01 2.80e-01   ph/cm2/s
 
Fluence   Cutoff-PL 4.60e-07 6.77e-07 6.19e-07 5.07e-07 2.03e-06 2.26e-06   erg/cm2
              Error 6.73e-08 8.51e-08 1.16e-07 6.68e-07 2.77e-07 8.18e-07   erg/cm2
Peak flux Cutoff-PL 4.28e-01 4.25e-01 2.64e-01 1.66e-01 1.21e+00 1.28e+00   ph/cm2/s
              Error 1.58e-01 1.03e-01 7.77e-02 1.44e-01 2.54e-01 3.25e-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    2.014    0.172    -      -           1.46e-03 1.66e-04   46.250 57
CPL   1.573    0.683      39.6    0.0      2.65e-03 0.00e+00   45.090 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.663    0.353    -      -           9.28e-03 2.04e-03   72.680 57
CPL   1.336    1.202      95.4    0.0      1.39e-02 4.21e-02   72.470 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: 35.264000 sec.
T50 in the 50-300 keV band: 17.216000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100  157.024  -19.920  137.104
T90   134.016  -13.168  120.848
T50    28.864    0.992   29.856
Peak    1.000    0.964    1.964

Click here for the BAT GCN circular template

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
   77.9618   -62.3194   0.0132    29.6528  -103.8504         4.3238461     14.555 TRIG_00831816                 
 
Foreground time interval of the image:
-19.920 137.104 (delta_t = 157.024 [sec])
Background time interval of the image:
-239.200 -19.920 (delta_t = 219.280 [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

8 ms binning

From T100_start-3 s to T100_start+3 s

2 ms binning

From T100_start-1 s to T100_start+1 s

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  -19.920 sec. to  137.104 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.01391     ( -0.168211   0.175944 )
Norm@50keV  : 1.46460E-03    ( -0.000167575   0.000164254 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.25 using 59 PHA bins.
# Reduced chi-squared =         0.8113 for     57 degrees of freedom 
# Null hypothesis probability =   8.449724e-01
 
Photon flux (15-150 keV)    in 157 sec: 0.221123 ( -0.020023  0.020033 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.12251e-06 ( -2.25548e-07  2.29715e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from  -19.920 sec. to  137.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.57317     ( -0.86097   0.504956 )
Epeak [keV] : 39.6227      (   )
Norm@50keV  : 2.65336E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.09 using 59 PHA bins.
# Reduced chi-squared =         0.8052 for     56 degrees of freedom 
# Null hypothesis probability =   8.513575e-01
 
Photon flux (15-150 keV)    in 157 sec: 0.217285 ( -0.02095  0.020906 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.01981e-06 ( -2.74667e-07  2.78881e-07 ) ergs/cm2

Band function

Time interval is from  -19.920 sec. to  137.104 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]    : 9.05669  (-0.893313  1.02208)
R^2/D10^2   : 0.149595  (-0.0514345   0.0758044)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.78 using 59 PHA bins.
# Reduced chi-squared =          1.119 for     57 degrees of freedom 
# Null hypothesis probability =   2.504768e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.763e-07   5.919e-08
25- 50  8.076e-07   9.326e-08
50-150  3.141e-07   8.337e-08
15-150  1.498e-06   1.731e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 63.3167       (-15.7206      24.1885)
Norm        : 1.12853       (-0.166795     0.192501)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.29 using 59 PHA bins.
# Reduced chi-squared =         0.7946 for     57 degrees of freedom 
# Null hypothesis probability =   8.682871e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.490e-07   6.107e-08
25- 50  6.944e-07   6.916e-08
50-150  8.256e-07   1.866e-07
15-150  1.969e-06   2.347e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 7.03495        (-1.05259      1.0834)
R1^2/D10^2  : 0.335401        (-0.135728      0.231528)
kT2 [keV]   : 30.2749        (-10.3909      31.3203)
R2^2/D10^2  : 9.65667E-04    (-0.000835185   0.00343847)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.63 using 59 PHA bins.
# Reduced chi-squared =         0.7023 for     55 degrees of freedom 
# Null hypothesis probability =   9.539920e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.424e-07   9.930e-08
25- 50  7.157e-07   2.191e-07
50-150  9.617e-07   4.995e-07
15-150  2.120e-06   6.722e-07

Peak spectrum fit

Power-law model

Time interval is from    0.964 sec. to    1.964 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.66318     ( -0.345225   0.360384 )
Norm@50keV  : 9.28494E-03    ( -0.00206269   0.00201206 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.68 using 59 PHA bins.
# Reduced chi-squared =          1.275 for     57 degrees of freedom 
# Null hypothesis probability =   7.874071e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.21775 ( -0.249739  0.25004 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.62561e-08 ( -1.98619e-08  2.02464e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.964 sec. to    1.964 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.33604     ( -1.45794   0.94639 )
Epeak [keV] : 95.4111      ( -95.4111 -95.4111 )
Norm@50keV  : 1.39286E-02    ( -0.0139286   0.0703357 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.47 using 59 PHA bins.
# Reduced chi-squared =          1.294 for     56 degrees of freedom 
# Null hypothesis probability =   6.853521e-02
 
Photon flux (15-150 keV)    in 1 sec: 1.20599 ( -0.253492  0.25354 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.41395e-08 ( -2.12845e-08  2.12895e-08 ) ergs/cm2

Band function

Time interval is from    0.964 sec. to    1.964 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]    : 12.5196  (-3.62021  5.14611)
R^2/D10^2   : 0.253642  (-0.177382   0.622193)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          80.25 using 59 PHA bins.
# Reduced chi-squared =          1.408 for     57 degrees of freedom 
# Null hypothesis probability =   2.289175e-02
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  8.429e-09   3.917e-09
25- 50  2.785e-08   1.064e-08
50-150  2.698e-08   1.408e-08
15-150  6.326e-08   2.219e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 153.440       (-86.5297      -150.81)
Norm        : 5.01308       (-1.08857     1.61585)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.48 using 59 PHA bins.
# Reduced chi-squared =          1.272 for     57 degrees of freedom 
# Null hypothesis probability =   8.111162e-02
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.285e-08   7.350e-09
25- 50  2.390e-08   1.339e-08
50-150  4.761e-08   2.882e-08
15-150  8.436e-08   4.933e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.58206        (-2.19386      2.84055)
R1^2/D10^2  : 1.90480        (-1.37875      6.54042)
kT2 [keV]   : 26.3684        (-22.0474      37.926)
R2^2/D10^2  : 1.33204E-02    (-0.0123093   0.0322005)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          70.66 using 59 PHA bins.
# Reduced chi-squared =          1.285 for     55 degrees of freedom 
# Null hypothesis probability =   7.592168e-02
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.394e-08   8.250e-09
25- 50  2.411e-08   1.295e-08
50-150  4.847e-08   2.713e-08
15-150  8.652e-08   4.549e-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: 2.01391     ( -0.168211   0.175944 )
Norm@50keV  : 1.46460E-03    ( -0.000167575   0.000164254 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.25 using 59 PHA bins.
# Reduced chi-squared =         0.8113 for     57 degrees of freedom 
# Null hypothesis probability =   8.449724e-01
 
Photon flux (15-150 keV)    in 157 sec: 0.221107 ( -0.0200213  0.0200303 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.12214e-06 ( -2.25851e-07  2.29748e-07 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.57452     ( -0.861438   0.569123 )
Epeak [keV] : 39.6405      (   )
Norm@50keV  : 2.64809E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.09 using 59 PHA bins.
# Reduced chi-squared =         0.8052 for     56 degrees of freedom 
# Null hypothesis probability =   8.513575e-01
 
Photon flux (15-150 keV)    in 157 sec: 0.217234 ( -0.020941  0.020898 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.02031e-06 ( -2.74828e-07  2.79146e-07 ) 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)  = 6.42e-07
S(50-100 keV) = 6.36e-07

T90 vs. Hardness ratio plot

T90                                   = 134.016000032425 sec.
Hardness ratio (energy fluence ratio) = 0.990654

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.24403
Count Ratio (50-100 keV) / (15-25 keV) = 0.571804

Mask shadow pattern

IMX = -1.362833035213309E-01, IMY = 5.527449941697828E-01

TIME vs. PHA plot around the trigger time

TIME vs. DetID plot around the trigger time

100 us light curve (15-350 keV)

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:
-239.200000 -19.920000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5219 -40.5346    1.5  27.1  -11.7   1.7423   7.5    1.2	Vela X-1                      
170.2985 -60.6388    1.1  10.7   79.8   2.1104  10.5    1.1	Cen X-3                       
186.5890 -62.7958    2.3  15.9  107.0   1.1129   5.0    2.4	GX 301-2                      
243.7065 -54.9592    2.3  42.7  135.2   3.1878   5.0 ------	UNKNOWN                       
215.3151 -62.6933    1.1  27.0  126.3   3.0266  10.8 ------	UNKNOWN                       
296.8690 -66.7000    3.1  44.8  175.1   1.6668   3.7 ------	UNKNOWN

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

Time interval of the image:
-19.920000 137.104000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5888 -40.6253    6.0  27.0  -11.6   0.3952   1.9    5.0	Vela X-1                      
169.9351 -60.6039    5.1  10.6   79.0  -0.3914  -2.3   11.3	Cen X-3                       
187.0189 -62.7230    7.8  16.1  107.1   0.2959   1.5   10.3	GX 301-2                      
241.0123 -54.4339    2.4  42.2  132.9   2.6371   4.8 ------	UNKNOWN                       
210.8343 -59.1936    2.4  27.5  117.3   1.2840   4.8 ------	UNKNOWN                       
 77.9618 -62.3194    0.8  29.7 -103.9   4.3238  14.5 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:

Plot creation:
Thu May 31 18:04:47 EDT 2018