Analysis for Trigger 745797

Analysis Summary

Notes:

Special note:

Due to the low partial coding fraction of this burst, the light curves and burst durations are created using the special DETECTION mask aperture. However, the spectral analysis is done using the default FLUX aperture for more accurate results, and thus the spectral analysis is only available after T+56.7 s (see figure below), when the burst came into the BAT calibrated field of view.

FLUX-mask-weighted light curve (pcodethresh=0.05; aperture=CALDB:FLUX)

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Thu Apr  6 15:38:29 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/prebascript/trigger745797/batgroup_hand_proc
======================================================================

  Trigger: 00745797      Segment: 000

  BAT Trigger Time: 513110407.296   [s; MET]
      Trigger Stop: 513110415.488   [s; MET]
               UTC: 2017-04-05T18:39:48.432100    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 219.810293944594   Dec: -25.24359290963  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.82
     Image Trigger?:     NO
     Rate S/N Ratio:     57.5325994545701  [ if not an image trigger ]
     Image S/N Ratio:    9.82

  Analysis Position:   [ source = BAT ]
    RA: 219.810293944594   Dec: -25.24359290963  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 219.824358637399   Dec: -25.2360176682354  [deg; J2000]  
        { 14h 39m 17.8s , -25d 14' 09.7" }
         +/- 1.31644644231929 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.466748336918744 [arcmin] (formal 1-sigma fit error)
    SNR: 20.5372545906635



  Partial Coding Fraction: 0.06933594    [ including projection effects ]

  Duration
     T90: 164.65600001812 +/- 35.3909366653105
        Measured from: -16.7680000066757
                   to: 147.888000011444     [s; relative to TRIGTIME]
     T50: 47.4720000624657 +/- 2.35857584961261
        Measured from: 0.84799998998642
                   to: 48.3200000524521     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 4.72399997711182     
                   to: 5.72399997711182     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -27.1359999775887     
                   to: 242.495999991894     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     7.099721  12.100800  11.708993   3.323140
           0.314019   0.310126   0.284668   0.222188 [error]
 Peak      0.214339   0.309089   0.289326   0.132567
           0.035467   0.040904   0.040553   0.029197 [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 5.51e-07 9.60e-07 1.28e-06 3.48e-06 3.72e-06 6.26e-06   erg/cm2
              Error 6.30e-08 6.80e-08 1.10e-07 6.60e-07 2.65e-07 7.45e-07   erg/cm2
Peak flux Power-law -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s
 
Fluence   Cutoff-PL 5.48e-07 9.63e-07 1.28e-06 3.34e-06 3.71e-06 6.09e-06   erg/cm2
              Error 6.50e-08 7.25e-08 1.15e-07 1.07e-06 2.80e-07 1.24e-06   erg/cm2
Peak flux Cutoff-PL -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   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    1.588    0.119    -      -           1.64e-03 1.09e-04   56.630 57
CPL   1.526    0.297     360.8    0.0      1.76e-03 7.56e-04   56.660 56
 
 
(1-s peak is outside the event data range; spectral analysis not available)
 
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
 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100  269.632  -27.136  242.496
T90   164.656  -16.768  147.888
T50    47.472    0.848   48.320
Peak    1.000    4.724    5.724

Image

15.0-350.0 keV image (Event data with DETECTION mask)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  219.8244   -25.2360   0.0095    41.3806    77.7872        28.2578041     20.537 TRIG_00745797                 
 
Foreground time interval of the image:
-27.136  50.605 (delta_t =  77.741 [sec])
Background time interval of the image:
-131.195 -27.136 (delta_t = 104.059 [sec])

Lightcurves

Notes:

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)

Spectra

Notes:

Time averaged spectrum fit using an average DRM

Power-law model
Time interval is from    56.7 sec. to  242.496 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.58757     ( -0.118019   0.119152 )
Norm@50keV  : 1.63914E-03    ( -0.000109373   0.000108921 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.63 using 59 PHA bins.
# Reduced chi-squared =         0.9934 for     57 degrees of freedom 
# Null hypothesis probability =   4.890564e-01
 
Photon flux (15-150 keV)    in 242.5 sec: 0.209841 ( -0.014136  0.014178 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.72368e-06 ( -2.66267e-07  2.67868e-07 ) ergs/cm2
 
Cutoff power-law model
Time interval is from    56.7 sec. to  242.496 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.52642     ( -0.433131   0.161658 )
Epeak [keV] : 360.758      ( -526.878 -526.878 )
Norm@50keV  : 1.75714E-03    ( -0.000434013   0.00107773 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.66 using 59 PHA bins.
# Reduced chi-squared =          1.012 for     56 degrees of freedom 
# Null hypothesis probability =   4.502083e-01
 
Photon flux (15-150 keV)    in 242.5 sec: 0.209475 ( -0.01485  0.01446 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.71493e-06 ( -2.88502e-07  2.73773e-07 ) ergs/cm2
 
Band function
Time interval is from    56.7 sec. to  242.496 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -0.695855   ( 1.11047   1.11047 )
beta        : -1.61349    ( 1.6061   0.13128 )
Epeak [keV] : 38.8998      ( -38.7872 450.52 )
Norm@50keV   : 7.17393E-03    ( -0.00741737   202806 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.33 using 59 PHA bins.
# Reduced chi-squared =          1.024 for     55 degrees of freedom 
# Null hypothesis probability =   4.247978e-01
 
Photon flux (15-150 keV)    in 242.5 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]    : 14.9928  (  )
R^2/D10^2   : 2.26833E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         127.10 using 59 PHA bins.
# Reduced chi-squared =         2.2297 for     57 degrees of freedom 
# Null hypothesis probability =   2.924707e-07
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.589e-07   3.477e-08
25- 50  1.028e-06   9.021e-08
50-150  1.573e-06   1.987e-07
15-150  2.860e-06   2.449e-07
Thermal bremsstrahlung (OTTB)
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 198.417       (-59.6701      -198.426)
Norm        : 0.847144       (-0.0548935     0.0630584)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.84 using 59 PHA bins.
# Reduced chi-squared =          1.015 for     57 degrees of freedom 
# Null hypothesis probability =   4.439090e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.119e-07   4.729e-08
25- 50  9.841e-07   1.434e-07
50-150  2.155e-06   7.692e-07
15-150  3.651e-06   8.608e-07
Double BB
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.20653        (-1.08964      1.30078)
R1^2/D10^2  : 0.360540        (-0.179178      0.402715)
kT2 [keV]   : 25.7061        (-4.06548      6.40869)
R2^2/D10^2  : 2.79808E-03    (-0.00151034   0.0024379)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.71 using 59 PHA bins.
# Reduced chi-squared =          1.013 for     55 degrees of freedom 
# Null hypothesis probability =   4.480418e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.458e-07   1.479e-07
25- 50  9.445e-07   1.889e-07
50-150  2.206e-06   5.447e-07
15-150  3.697e-06   7.936e-07
Webpage updated on:
Thu Apr  6 21:07:34 EDT 2017