Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Mon Jan 20 08:32:41 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger284856
======================================================================

  Trigger: 00284856      Segment: 000

  BAT Trigger Time: 206081971.712   [s; MET]
      Trigger Stop: 206081971.84   [s; MET]
               UTC: 2007-07-14T04:59:29.626060    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 57.8541785265274   Dec: 28.2952010314712  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    12.12
     Image Trigger?:     NO
     Rate S/N Ratio:     76.5963445602987  [ if not an image trigger ]
     Image S/N Ratio:    12.12

  Analysis Position:   [ source = BAT ]
    RA: 57.8541785265274   Dec: 28.2952010314712  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 57.8580069318728   Dec: 28.2938793564468  [deg; J2000]  
        { 03h 51m 25.9s , +28d 17' 38.0" }
         +/- 1.37861138043568 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.624620880094939 [arcmin] (formal 1-sigma fit error)
    SNR: 19.2271858352427
 
  Angular difference between the analysis and refined position is 0.217250 arcmin
 
  Partial Coding Fraction: 0.9375    [ including projection effects ]

  Duration
     T90: 65.636000007391 +/- 9.50873367717039
        Measured from: -0.496000021696091
                   to: 65.1399999856949     [s; relative to TRIGTIME]
     T50: 40.1800000071526 +/- 8.52704874666197
        Measured from: 0.123999983072281
                   to: 40.3039999902248     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.388000011444092     
                   to: 0.611999988555908     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.792000025510788     
                   to: 74.6399999856949     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.332500   0.392123   0.354491   0.144105
           0.040891   0.042994   0.039253   0.037870 [error]
 Peak      0.066627   0.115140   0.134143   0.055229
           0.005636   0.006609   0.006767   0.006027 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   75.432   -0.792   74.640
T90    65.636   -0.496   65.140
T50    40.180    0.124   40.304
Peak    1.000   -0.388    0.612
 
 
====== 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      -1.368    -0.191      0.191       -           -               -         1.01e-03     -1.10e-04          1.10e-04      51.340   57
CPL     -1.154    -0.386      0.882      192.503    -192.503      -192.503      1.30e-03     -5.42e-04          2.33e-03      51.120   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      -0.882     -0.103     0.105       -           -               -         2.40e-02     -1.36e-03          1.35e-03      38.960   57
CPL     -0.878     -0.102     0.192     9999.360    -9999.360      -9999.360      2.41e-02     -1.33e-03          8.39e-03      38.990   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   8.57e-08  1.71e-07  2.65e-07  9.01e-07  7.39e-07  1.42e-06   erg/cm2
      90%_error_low -1.55e-08 -1.91e-08 -3.80e-08 -2.51e-07 -9.20e-08 -2.84e-07   erg/cm2
      90%_error_hi   1.62e-08  1.90e-08  3.79e-08  3.14e-07  9.34e-08  3.38e-07   erg/cm2
Peak flux       PL   5.48e-01  7.98e-01  8.66e-01  1.76e+00  2.75e+00  3.97e+00   ph/cm2/s
      90%_error_low -6.53e-02 -5.77e-02 -5.33e-02 -2.34e-01 -1.55e-01 -2.63e-01   ph/cm2/s
      90%_error_hi   6.82e-02  5.71e-02  5.29e-02  2.58e-01  1.55e-01  2.72e-01   ph/cm2/s
 
Fluence        CPL   8.30e-08  1.75e-07  2.67e-07  6.26e-07  7.23e-07  1.15e-06   erg/cm2
      90%_error_low -1.85e-08 -2.23e-08 -3.94e-08 -4.31e-07 -1.09e-07 -4.45e-07   erg/cm2
      90%_error_hi   1.57e-08  2.46e-08  4.04e-08  3.19e-07  1.05e-07  3.67e-07   erg/cm2
Peak flux      CPL   5.47e-01  7.98e-01  8.67e-01  1.74e+00  2.75e+00  4.13e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A   -1.55e-01 -7.28e-01   ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A    1.55e-01  9.18e-02   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
   57.8580    28.2939   0.0100    13.1589   -74.7912         0.7654362     19.227 TRIG_00284856                 
 
Foreground time interval of the image:
 -0.792  16.589 (delta_t =  17.381 [sec])
Background time interval of the image:
-239.712  -0.792 (delta_t = 238.920 [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   -0.792 sec. to   74.640 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.36782     ( -0.1914   0.191101 )
Norm@50keV  : 1.00719E-03    ( -0.000110233   0.000109566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.34 using 59 PHA bins.
# Reduced chi-squared =         0.9008 for     57 degrees of freedom 
# Null hypothesis probability =   6.863172e-01
 
Photon flux (15-150 keV)    in 75.43 sec: 0.121793 ( -0.013012  0.01302 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.39187e-07 ( -9.19937e-08  9.34472e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.792 sec. to   74.640 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.15382     ( -0.386284   0.881769 )
Epeak [keV] : 192.503      ( -192.564 -192.564 )
Norm@50keV  : 1.29988E-03    ( -0.000542281   0.00233166 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.12 using 59 PHA bins.
# Reduced chi-squared =         0.9128 for     56 degrees of freedom 
# Null hypothesis probability =   6.599072e-01
 
Photon flux (15-150 keV)    in 75.43 sec: 0.120535 ( -0.013836  0.013702 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.22976e-07 ( -1.09307e-07  1.05241e-07 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from   -0.388 sec. to    0.612 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.882076     ( -0.103392   0.104985 )
Norm@50keV  : 2.39804E-02    ( -0.00135538   0.00135024 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.96 using 59 PHA bins.
# Reduced chi-squared =         0.6834 for     57 degrees of freedom 
# Null hypothesis probability =   9.675984e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.75217 ( -0.1551  0.15524 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.71044e-07 ( -1.71163e-08  1.72131e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from   -0.388 sec. to    0.612 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.87783     ( -0.102189   0.192298 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 2.41288E-02    ( -0.0013436   0.00837026 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.99 using 59 PHA bins.
# Reduced chi-squared =         0.6962 for     56 degrees of freedom 
# Null hypothesis probability =   9.592945e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.75138 ( -0.15507  0.15516 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.72264e-07 ( -1.84883e-08  1.57741e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 65.636 sec.
Hardness ratio (energy fluence ratio) = 1.54995819251

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

    S(15-50 keV)  = 2.5649926e-07
S(50-150 keV) = 4.826799e-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 = 6.133183606488909E-02, IMY = 2.256021352703911E-01

    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:
-239.712000 -0.792000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6355  22.0197    0.5  37.3  -76.7   9.9636  24.4    0.3	Crab                          
  2.7555  78.3615    2.7  51.2 -179.1   1.8848   4.3 ------	UNKNOWN                       
 65.8802  -7.3724    2.6  43.6  -23.7   1.2445   4.5 ------	UNKNOWN                       
 79.0084  33.7353    2.3  30.6  -95.6   1.3887   5.1 ------	UNKNOWN                       
 94.1564  41.1172    2.5  42.4 -108.9   3.4068   4.6 ------	UNKNOWN

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

    Time interval of the image:
-0.792000 16.588590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.4543  21.9367    7.2  37.1  -76.5   0.1508   1.6   11.0	Crab                          
  7.2265  18.8591    1.9  34.2   89.4   0.6140   6.0 ------	UNKNOWN                       
  2.9835  29.9667    2.1  34.4  110.4   0.4982   5.5 ------	UNKNOWN                       
 31.4762  -5.3897    2.2  37.3   29.5   0.3644   5.2 ------	UNKNOWN                       
 57.8580  28.2939    0.6  13.2  -74.8   0.7655  19.2 ------	UNKNOWN                       
 75.3790  31.0026    2.2  27.8  -89.5   0.2899   5.3 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
50.788590 962.391300
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6278  22.0126    0.2  24.1  -75.1  39.3700  61.3    0.3	Crab                          
 26.9041  52.3975    3.9  33.2  150.8   2.1986   3.0 ------	UNKNOWN                       
 75.7635  61.0816    3.8  34.9 -159.3   1.6818   3.0 ------	UNKNOWN                       
125.6337  82.4054    3.3  59.1 -166.1  12.2620   3.5 ------	UNKNOWN                       
103.8272  44.6027    2.2  39.8 -121.2   5.5468   5.1 ------	UNKNOWN