Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 03:30:09 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger306858
======================================================================

  Trigger: 00306858      Segment: 000

  BAT Trigger Time: 227680661.12   [s; MET]
      Trigger Stop: 227680662.528   [s; MET]
               UTC: 2008-03-20T04:37:38.464040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 177.780563457759   Dec: 57.1439944141214  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.64
     Image Trigger?:     NO
     Rate S/N Ratio:     9.9498743710662  [ if not an image trigger ]
     Image S/N Ratio:    7.64

  Analysis Position:   [ source = BAT ]
    RA: 177.780563457759   Dec: 57.1439944141214  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 177.76947854575   Dec: 57.1649626544674  [deg; J2000]  
        { 11h 51m 04.7s , +57d 09' 53.9" }
         +/- 1.65599568147119 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.720250420995516 [arcmin] (formal 1-sigma fit error)
    SNR: 14.7971019435478
 
  Angular difference between the analysis and refined position is 1.308789 arcmin
 
  Partial Coding Fraction: 0.9375    [ including projection effects ]

  Duration
     T90: 13.8160000145435 +/- 1.8587436576694
        Measured from: -1.1240000128746
                   to: 12.6920000016689     [s; relative to TRIGTIME]
     T50: 7.22000002861023 +/- 2.25913347151323
        Measured from: 0.431999981403351
                   to: 7.65200001001358     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.0519999861717224     
                   to: 1.05199998617172     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.67199999094009     
                   to: 13.8479999899864     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.141806   0.183449   0.121112   0.050930
           0.018450   0.019370   0.017628   0.016211 [error]
 Peak      0.016449   0.027019   0.021605   0.008083
           0.004815   0.005193   0.004666   0.004124 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   15.520   -1.672   13.848
T90    13.816   -1.124   12.692
T50     7.220    0.432    7.652
Peak    1.000    0.052    1.052
 
 
====== 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      -1.623    -0.214      0.209       -           -               -         1.96e-03     -2.58e-04          2.53e-04      43.190   57
CPL     -1.508    -0.326      0.906      189.724    -189.724      -189.724      2.27e-03     -5.65e-04          4.98e-03      43.130   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      -1.327     -0.353     0.357       -           -               -         4.66e-03     -9.89e-04          9.84e-04      56.080   57
CPL     -0.734      N/A       N/A         104.773      N/A           N/A         9.43e-03        N/A               N/A         55.540   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   4.35e-08  7.42e-08  9.64e-08  2.53e-07  2.83e-07  4.67e-07   erg/cm2
      90%_error_low -7.79e-09 -8.72e-09 -1.70e-08 -8.14e-08 -3.99e-08 -9.91e-08   erg/cm2
      90%_error_hi   8.04e-09  8.70e-09  1.71e-08  1.05e-07  4.07e-08  1.18e-07   erg/cm2
Peak flux       PL   1.62e-01  1.81e-01  1.44e-01  1.91e-01  5.58e-01  6.79e-01   ph/cm2/s
      90%_error_low -5.63e-02 -4.20e-02 -3.72e-02 -8.38e-02 -1.18e-01 -1.48e-01   ph/cm2/s
      90%_error_hi   6.17e-02  4.11e-02  3.67e-02  1.18e-01  1.19e-01  1.52e-01   ph/cm2/s
 
Fluence        CPL   4.31e-08  7.53e-08  9.65e-08  2.03e-07  2.80e-07  4.18e-07   erg/cm2
      90%_error_low -8.55e-09 -9.71e-09 -1.77e-08 -1.55e-07 -4.82e-08 -1.65e-07   erg/cm2
      90%_error_hi   7.54e-09  1.19e-08  1.75e-08  6.94e-08  4.38e-08  8.25e-08   erg/cm2
Peak flux      CPL   1.48e-01  1.93e-01  1.51e-01  9.66e-02  5.47e-01  5.88e-01   ph/cm2/s
      90%_error_low -6.57e-02 -4.92e-02 -4.08e-02 -9.66e-02 -1.22e-01 -1.53e-01   ph/cm2/s
      90%_error_hi   6.97e-02  5.38e-02  4.29e-02  1.26e-01  1.22e-01  1.80e-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
  177.7695    57.1650   0.0130    22.0875  -178.3213         0.4939436     14.797 TRIG_00306858                 
 
Foreground time interval of the image:
 -1.672  13.848 (delta_t =  15.520 [sec])
Background time interval of the image:
-239.120  -1.672 (delta_t = 237.448 [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   -1.672 sec. to   13.848 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.62256     ( -0.214044   0.208911 )
Norm@50keV  : 1.95787E-03    ( -0.000257725   0.000252945 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.19 using 59 PHA bins.
# Reduced chi-squared =         0.7577 for     57 degrees of freedom 
# Null hypothesis probability =   9.117879e-01
 
Photon flux (15-150 keV)    in 15.52 sec: 0.253394 ( -0.029666  0.029672 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.83467e-07 ( -3.98696e-08  4.071e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -1.672 sec. to   13.848 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.50765     ( -0.324722   0.907669 )
Epeak [keV] : 189.724      ( -192.582 -192.582 )
Norm@50keV  : 2.27049E-03    ( -0.000559039   0.00498659 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.13 using 59 PHA bins.
# Reduced chi-squared =         0.7702 for     56 degrees of freedom 
# Null hypothesis probability =   8.961430e-01
 
Photon flux (15-150 keV)    in 15.52 sec: 0.252214 ( -0.030803  0.030476 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.79596e-07 ( -4.82234e-08  4.3783e-08 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    0.052 sec. to    1.052 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.32727     ( -0.353286   0.35733 )
Norm@50keV  : 4.65631E-03    ( -0.000988862   0.000984201 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.08 using 59 PHA bins.
# Reduced chi-squared =         0.9838 for     57 degrees of freedom 
# Null hypothesis probability =   5.097363e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.558404 ( -0.118438  0.118649 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.57193e-08 ( -1.07465e-08  1.09581e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    0.052 sec. to    1.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.733508     (       )
Epeak [keV] : 104.773      (   )
Norm@50keV  : 9.43428E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.54 using 59 PHA bins.
# Reduced chi-squared =         0.9917 for     56 degrees of freedom 
# Null hypothesis probability =   4.923194e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.546845 ( -0.122179  0.121719 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.34851e-08 ( -1.20569e-08  1.20874e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 13.816 sec.
Hardness ratio (energy fluence ratio) = 1.29909219122

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

    S(15-50 keV)  = 1.177637e-07
S(50-150 keV) = 1.6570476e-07

    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 = -4.056294241503268E-01, IMY = 1.188761161799625E-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:
-239.120000 -1.672000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3504  35.4530    9.0  37.3  -48.2   0.3554   1.3    8.5	Her X-1                       
204.9581  -2.2351    2.6  46.3   47.2   3.3904   4.4 ------	UNKNOWN                       
220.0524  24.3710    2.4  22.7   11.3   0.8379   4.8 ------	UNKNOWN                       
223.8137  42.3050    2.1  12.8  -42.8   0.8491   5.4 ------	UNKNOWN                       
272.4188  64.6508    3.3  41.1  -98.2   3.3110   3.6 ------	UNKNOWN

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

    Time interval of the image:
-1.672000 13.848000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3080  35.2121   12.6  37.4  -47.9  -0.0549  -0.9   10.7	Her X-1                       
191.1070   6.1474    2.6  40.2   69.2   0.6407   4.5 ------	UNKNOWN                       
177.7695  57.1650    0.8  22.1 -178.3   0.4939  14.8 ------	UNKNOWN                       
233.1466  20.3869    2.1  32.5   -6.6   0.2241   5.5 ------	UNKNOWN                       
207.8806  52.8815    2.0   8.9 -128.7   0.1889   5.7 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
81.980600 93.980590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3764  35.4802    6.0  20.2   21.4  -0.0599  -1.9    9.2	Her X-1                       
268.4484  -1.4423    2.6  57.4   -0.9   0.8041   4.4    4.9	SW J1753.5-0127               
288.7043  10.8776   20.3  50.2  -28.9  -0.0460  -0.6    6.9	GRS 1915+105                  
299.5540  35.1577    2.7  34.2  -60.5   0.2263   4.2    3.2	Cyg X-1                       
308.1798  41.0285    5.8  34.9  -76.3   0.1265   2.0    5.5	Cyg X-3                       
256.8826   0.3139    2.4  55.1   13.0   0.8086   4.9 ------	UNKNOWN                       
234.9479  45.9162    1.9  17.8   78.3   0.2117   6.2 ------	UNKNOWN                       
265.0477   6.2056    2.2  49.4    2.5   0.3417   5.3 ------	UNKNOWN                       
 89.7630  65.9263    2.0  58.4 -174.7   1.0499   5.6 ------	UNKNOWN                       
344.6890  56.7460    2.5  44.6 -118.5   0.5615   4.6 ------	UNKNOWN