Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Wed Jan 22 16:43:47 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger208275
======================================================================

  Trigger: 00208275      Segment: 000

  BAT Trigger Time: 168283482.204   [s; MET]
      Trigger Stop: 168283482.268   [s; MET]
               UTC: 2006-05-02T17:24:41.035100    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) TDRSS scaled map message

  BAT 
    RA: 278.935719107924   Dec: 52.6321691479945  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    11.47
     Image Trigger?:     NO
     Rate S/N Ratio:     32.9696830436691  [ if not an image trigger ]
     Image S/N Ratio:    11.47

  Analysis Position:   [ source = BAT ]
    RA: 278.935719107924   Dec: 52.6321691479945  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 278.961492631607   Dec: 52.6269420502663  [deg; J2000]  
        { 18h 35m 50.8s , +52d 37' 37.0" }
         +/- 1.75428350816523 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.708716180793054 [arcmin] (formal 1-sigma fit error)
    SNR: 13.6271302706973
 
  Angular difference between the analysis and refined position is 0.989630 arcmin
 
  Partial Coding Fraction: 0.921875    [ including projection effects ]

  Duration
     T90: 0.143999993801117 +/- 0.0505964225831327
        Measured from: -0.00400000810623169
                   to: 0.139999985694885     [s; relative to TRIGTIME]
     T50: 0.0479999780654907 +/- 0.0160000026226044
        Measured from: 0.0119999945163727
                   to: 0.0599999725818634     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.407999992370605     
                   to: 0.592000007629395     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.00400000810623169     
                   to: 0.171999990940094     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.009132   0.023403   0.026429   0.008236
           0.002475   0.002833   0.002766   0.002246 [error]
 Peak      0.011024   0.022911   0.032944   0.017131
           0.005164   0.005578   0.004995   0.004490 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    0.176   -0.004    0.172
T90     0.144   -0.004    0.140
T50     0.048    0.012    0.060
Peak    1.000   -0.408    0.592
 
 
====== 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      -0.985    -0.198      0.205       -           -               -         2.57e-02     -3.14e-03          3.14e-03      56.960   57
CPL     -0.105    -0.887      1.178      117.949     -39.490      -117.949      6.62e-02     -4.08e-02          1.57e-01      54.260   56
 
 
=== 1-s peak 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      -0.815     -0.342     0.379       -           -               -         5.35e-03     -1.12e-03          1.09e-03      65.160   57
CPL     -0.401     -0.696     2.105      231.430    -231.430      -231.430      8.01e-03     -3.64e-03          4.71e-02      64.940   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   3.57e-09  9.01e-09  1.82e-08  9.26e-08  4.92e-08  1.23e-07   erg/cm2
      90%_error_low -8.16e-10 -1.32e-09 -2.45e-09 -2.47e-08 -6.45e-09 -2.65e-08   erg/cm2
      90%_error_hi   8.75e-10  1.30e-09  2.43e-09  3.05e-08  6.49e-09  3.14e-08   erg/cm2
Peak flux       PL   1.15e-01  1.74e-01  1.98e-01  4.29e-01  6.15e-01  9.15e-01   ph/cm2/s
      90%_error_low -4.73e-02 -4.84e-02 -3.89e-02 -1.61e-01 -1.24e-01 -1.91e-01   ph/cm2/s
      90%_error_hi   5.63e-02  4.73e-02  3.86e-02  2.24e-01  1.25e-01  2.11e-01   ph/cm2/s
 
Fluence        CPL   2.96e-09  9.72e-09  1.98e-08  3.18e-08  4.67e-08  6.43e-08   erg/cm2
      90%_error_low -1.00e-09 -1.56e-09 -2.96e-09 -1.95e-08 -7.27e-09 -2.03e-08   erg/cm2
      90%_error_hi   1.06e-09  1.63e-09  3.05e-09  6.23e-08  7.12e-09  6.03e-08   erg/cm2
Peak flux      CPL   1.01e-01  1.76e-01  2.08e-01  2.88e-01  6.04e-01  7.74e-01   ph/cm2/s
      90%_error_low -6.09e-02 -5.12e-02 -4.66e-02 -2.88e-01 -1.31e-01 -2.64e-01   ph/cm2/s
      90%_error_hi   6.65e-02  5.17e-02  5.32e-02  1.92e-01  1.28e-01  2.87e-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
  278.9615    52.6269   0.0142    23.1736    -2.2798         0.0691768     13.627 TRIG_00208275                 
 
Foreground time interval of the image:
 -0.004   0.172 (delta_t =   0.176 [sec])
Background time interval of the image:
-239.204  -0.004 (delta_t = 239.200 [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:




    Spectra

    Notes:

    Time averaged spectrum fit using the average DRM

    Power-law model
    Time interval is from   -0.004 sec. to    0.172 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.984509     ( -0.197722   0.205259 )
Norm@50keV  : 2.56841E-02    ( -0.00314486   0.00313586 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.96 using 59 PHA bins.
# Reduced chi-squared =         0.9993 for     57 degrees of freedom 
# Null hypothesis probability =   4.766408e-01
 
Photon flux (15-150 keV)    in 0.176 sec: 2.95473 ( -0.36602  0.36674 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.91579e-08 ( -6.44952e-09  6.48926e-09 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.004 sec. to    0.172 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.105205     ( -0.886987   1.17757 )
Epeak [keV] : 117.949      ( -39.4884 -117.948 )
Norm@50keV  : 6.61776E-02    ( -0.0407555   0.157348 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.26 using 59 PHA bins.
# Reduced chi-squared =         0.9688 for     56 degrees of freedom 
# Null hypothesis probability =   5.411845e-01
 
Photon flux (15-150 keV)    in 0.176 sec: 2.87306 ( -0.38053  0.37854 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.67211e-08 ( -7.26972e-09  7.12476e-09 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.408 sec. to    0.592 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.81469     ( -0.342204   0.378748 )
Norm@50keV  : 5.35001E-03    ( -0.00112329   0.00109114 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          65.16 using 59 PHA bins.
# Reduced chi-squared =          1.143 for     57 degrees of freedom 
# Null hypothesis probability =   2.141249e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.614591 ( -0.123743  0.124867 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.21427e-08 ( -1.24903e-08  1.25761e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.408 sec. to    0.592 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.400811     ( -0.697057   2.10383 )
Epeak [keV] : 231.430      ( -230.764 -230.764 )
Norm@50keV  : 8.00821E-03    ( -0.00365104   0.0470928 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.94 using 59 PHA bins.
# Reduced chi-squared =          1.160 for     56 degrees of freedom 
# Null hypothesis probability =   1.933528e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.603705 ( -0.13115  0.127525 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.09495e-08 ( -1.39655e-08  1.32259e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 0.144 sec.
Hardness ratio (energy fluence ratio) = 2.02162380414

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

    S(15-50 keV)  = 1.2579953e-08
S(50-150 keV) = 3.65777e-08

    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 = 4.277172360753796E-01, IMY = 1.702765592760256E-02

    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:
-239.204000 -0.004000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.5182  35.3604    2.0  32.2   48.5   1.7895   5.9    3.2	Her X-1                       
299.5934  35.1977    0.5  45.7   -7.5   7.6849  23.4    0.3	Cyg X-1                       
308.2401  41.1354    0.0  44.0  -20.1  -0.3293  -1.1   12.4	Cyg X-3                       
326.2671  38.1966    0.0  53.6  -33.9   0.4770   0.5    8.8	Cyg X-2                       
 14.8768  68.8429    3.1  40.9  -87.1   3.2845   3.7 ------	UNKNOWN

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

    Time interval of the image:
-0.004000 0.172000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4158  35.2768   11.4  32.3   48.6   0.0088   1.0    4.4	Her X-1                       
299.7345  35.1788   14.1  45.8   -7.6  -0.0075  -0.8    7.2	Cyg X-1                       
307.9743  40.8321  152.1  44.2  -19.6   0.0007   0.1    9.5	Cyg X-3                       
326.2043  38.2853   30.7  53.5  -33.9  -0.0080  -0.4    2.7	Cyg X-2                       
278.9615  52.6269    0.8  23.2   -2.3   0.0692  13.6 ------	UNKNOWN                       
139.8548  43.8415    2.6  54.5 -170.9   0.0651   4.4 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
54.496590 962.846800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4447  35.3133    0.9  24.5   88.6   8.5507  12.3    1.9	Her X-1                       
288.8186  10.9581    1.1  42.4   19.4  10.2839  10.8    1.4	GRS 1915+105                  
299.5900  35.2024    0.2  22.7  -14.4  32.8112  66.3    0.1	Cyg X-1                       
307.9242  40.9284    5.9  22.8  -37.0   0.9911   2.0    8.6	Cyg X-3                       
326.1975  38.3245    4.3  35.3  -51.6   1.9256   2.7    1.2	Cyg X-2                       
254.8539  26.6079    2.6  31.6   77.9   4.1894   4.4 ------	UNKNOWN                       
140.6897  63.8636    3.2  59.1 -166.2  14.1297   3.7 ------	UNKNOWN                       
106.7038  80.0343    2.9  47.3 -148.0   4.6771   3.9 ------	UNKNOWN