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: Wed Apr 26 14:19:58 EDT 2017
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger745797
======================================================================

  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: 219.82396483382   Dec: -25.2364074660541  [deg; J2000]  
        { 14h 39m 17.8s , -25d 14' 11.1" }
         +/- 1.31214961623829 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.471966533934874 [arcmin] (formal 1-sigma fit error)
    SNR: 20.633396604929
 
  Angular difference between the analysis and refined position is 0.858108 arcmin
 
  Partial Coding Fraction: 0.06933594    [ including projection effects ]

  Duration
     T90: 165.31200003624 +/- 32.8929220435928
        Measured from: -16.8159999847412
                   to: 148.496000051498     [s; relative to TRIGTIME]
     T50: 47.5200000405312 +/- 2.54092891581977
        Measured from: 0.751999974250793
                   to: 48.272000014782     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 4.30799996852875     
                   to: 5.30799996852875     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -27.1040000319481     
                   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     6.726083  11.928841  12.148617   3.838516
           0.312249   0.314560   0.289388   0.228585 [error]
 Peak      0.214446   0.306150   0.378312   0.076191
           0.036772   0.041449   0.043702   0.031248 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  269.600  -27.104  242.496
T90   165.312  -16.816  148.496
T50    47.520    0.752   48.272
Peak    1.000    4.308    5.308
 
 
====== 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      -1.515    -0.119      0.118       -           -               -         2.20e-03     -1.43e-04          1.43e-04      63.350   57
CPL     -1.516    -0.116      0.158     9999.360    -9999.360      -9999.360      2.21e-03     -5.04e-04          7.78e-04      63.370   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      N/A         N/A       N/A          -           -               -           N/A           N/A               N/A         N/A        N/A   
CPL     N/A         N/A       N/A          N/A         N/A           N/A           N/A           N/A               N/A         N/A        N/A   
 
 
=== 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   5.30e-07  9.66e-07  1.35e-06  3.96e-06  3.88e-06  6.81e-06   erg/cm2
      90%_error_low -6.13e-08 -6.70e-08 -1.14e-07 -6.93e-07 -2.73e-07 -7.80e-07   erg/cm2
      90%_error_hi   6.36e-08  6.66e-08  1.14e-07  7.89e-07  2.75e-07  8.56e-07   erg/cm2
Peak flux       PL     N/A      N/A      N/A      N/A      N/A      N/A     ph/cm2/s
  • Special notes of this burst




    Image




    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:




    Spectra

    Notes:

    Time averaged spectrum fit using the average DRM

    Power-law model
    Time interval is from   56.700 sec. to  242.496 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.5148     ( -0.118727   0.118421 )
Norm@50keV  : 2.20437E-03    ( -0.000143329   0.000142976 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.35 using 59 PHA bins.
# Reduced chi-squared =          1.111 for     57 degrees of freedom 
# Null hypothesis probability =   2.624303e-01
 
Photon flux (15-150 keV)    in 185.8 sec: 0.276308 ( -0.018512  0.018569 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.87664e-06 ( -2.73299e-07  2.7496e-07 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   56.700 sec. to  242.496 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.51618     ( -0.116146   0.157876 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 2.20664E-03    ( -0.000507137   0.000774694 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.37 using 59 PHA bins.
# Reduced chi-squared =          1.132 for     56 degrees of freedom 
# Null hypothesis probability =   2.325820e-01
 
Photon flux (15-150 keV)    in 185.8 sec: 0.277438 ( -0.023788  0.021511 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.9136e-06 ( -3.11581e-07  2.37047e-07 ) ergs/cm2

    1-s peak spectrum fit

    1-s peak spectrum unavailable, likely because there are no event data in the 1-s peak range.

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 165.312 sec.
Hardness ratio (energy fluence ratio) = 1.39981310254

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

    S(15-50 keV)  = 1.4959559e-06
S(50-150 keV) = 2.380749e-06

    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.




    Spacecraft aspect plot

    Bright source in the event data image

    Event data image of 15-350 keV band 

    Time interval of the image:
-27.104000 50.604600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
245.0193 -15.5905    4.4  23.8  113.6  -0.6572  -2.6    3.8	Sco X-1                       
256.1332 -38.0218    0.0  12.4   34.8  -0.1799  -1.1   12.7	4U 1700-377                   
256.2902 -36.2461    0.0  11.2   41.0   0.1280   0.7   12.7	GX 349+2                      
262.8677 -24.5779    0.0   5.4  137.5  -0.4946  -2.8   12.7	GX 1+4                        
264.5410 -44.4380    7.3  15.5   -1.0  -0.2661  -1.6    8.7	4U 1735-44                    
268.2219  -1.5752   23.6  27.5  177.9  -0.1003  -0.5   11.4	SW J1753.5-0127               
270.1271 -25.0954    4.4   5.1 -144.8  -0.4512  -2.6    8.6	GX 5-1                        
270.2859 -25.7696    7.7   4.7 -138.2   0.2708   1.5    1.8	GRS 1758-258                  
274.0533 -14.0183    6.8  16.6 -159.1  -0.3009  -1.7    3.0	GX 17+2                       
275.8760 -30.2177    9.6   8.3  -85.2  -0.2052  -1.2    9.3	H1820-303                     
285.1141 -24.7743    3.2  17.2 -105.8  -0.5875  -3.6    9.7	HT1900.1-2455                 
288.8859  11.0761    8.4  45.6 -154.3  -0.3515  -1.4    9.4	GRS 1915+105                  
263.0403 -33.8545   81.6   5.7   23.8  -0.0239  -0.1    2.8	GX 354-0                      
224.0955 -16.1367    3.4  40.9   92.9   4.1724   3.4 ------	UNKNOWN                       
219.8240 -25.2364    0.6  41.4   77.8  28.5590  20.6 ------	UNKNOWN                       
283.2185 -26.1987    2.5  15.1 -102.6   0.7911   4.7 ------	UNKNOWN                       

    Webpage updated on:
Wed Apr 26 16:41:20 EDT 2017