Analysis Summary

Notes:

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun May 10 04:00:45 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger531223
======================================================================

  Trigger: 00531223      Segment: 000

  BAT Trigger Time: 366837524.288   [s; MET]
      Trigger Stop: 366837528.384   [s; MET]
               UTC: 2012-08-16T19:18:34.743480    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 282.126089347899   Dec: -6.9789643544855  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    6.94
     Image Trigger?:     NO
     Rate S/N Ratio:     10.2469507659596  [ if not an image trigger ]
     Image S/N Ratio:    6.94

  Analysis Position:   [ source = BAT ]
    RA: 282.126089347899   Dec: -6.9789643544855  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 282.130627737682   Dec: -6.97900129061139  [deg; J2000]  
        { 18h 48m 31.4s , -06d 58' 44.4" }
         +/- 2.17330971092898 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.847054394451738 [arcmin] (formal 1-sigma fit error)
    SNR: 10.0349696864783
 
  Angular difference between the analysis and refined position is 0.270295 arcmin
 
  Partial Coding Fraction: 0.09277344    [ including projection effects ]

  Duration
     T90: 4.432000041008 +/- 0.976917597564729
        Measured from: 0.568000018596649
                   to: 5.00000005960464     [s; relative to TRIGTIME]
     T50: 2.2720000743866 +/- 0.679199513816435
        Measured from: 1.46399998664856
                   to: 3.73600006103516     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.828000009059906     
                   to: 1.82800000905991     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.280000030994415     
                   to: 5.06400001049042     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.296047   0.269451   0.120115   0.007397
           0.043321   0.043974   0.036089   0.030784 [error]
 Peak      0.041899   0.114316   0.043619   0.008267
           0.019554   0.019751   0.017046   0.013733 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    4.784    0.280    5.064
T90     4.432    0.568    5.000
T50     2.272    1.464    3.736
Peak    1.000    0.828    1.828
 
 
====== 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      -2.509    -0.395      0.335       -           -               -         7.77e-03     -2.17e-03          2.10e-03      54.340   57
CPL     -1.493    -0.509      1.939       18.991      N/A           N/A         3.26e-02        N/A               N/A         53.030   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      -1.989     -0.445     0.402       -           -               -         1.37e-02     -3.94e-03          3.82e-03      58.020   57
CPL      0.179     -2.332     4.821       45.071     -27.871       -45.071      2.07e-01     -2.07e-01          1.17e+02      55.650   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   1.24e-07  1.24e-07  8.69e-08  9.69e-08  3.73e-07  4.31e-07   erg/cm2
      90%_error_low -2.61e-08 -2.41e-08 -3.10e-08 -5.27e-08 -7.63e-08 -1.06e-07   erg/cm2
      90%_error_hi   2.67e-08  2.34e-08  3.35e-08  8.21e-08  7.88e-08  1.25e-07   erg/cm2
Peak flux       PL   9.02e-01  6.81e-01  3.43e-01  2.48e-01  2.04e+00  2.17e+00   ph/cm2/s
      90%_error_low -3.25e-01 -1.77e-01 -1.21e-01 -1.35e-01 -5.40e-01 -5.59e-01   ph/cm2/s
      90%_error_hi   3.54e-01  1.76e-01  1.21e-01  1.94e-01  5.43e-01  5.60e-01   ph/cm2/s
 
Fluence        CPL    N/A      N/A      N/A      N/A      N/A      N/A      erg/cm2
      90%_error_low -2.61e-08 -2.41e-08 -3.10e-08 -5.27e-08 -7.63e-08 -1.06e-07   erg/cm2
      90%_error_hi   2.67e-08  2.34e-08  3.35e-08  8.21e-08  7.88e-08  1.25e-07   erg/cm2
Peak flux      CPL   6.68e-01  8.43e-01  3.64e-01  3.86e-02  1.91e+00  1.91e+00   ph/cm2/s
      90%_error_low -3.94e-01 -2.52e-01 -1.91e-01 -3.86e-02 -5.69e-01 -5.73e-01   ph/cm2/s
      90%_error_hi   4.38e-01  2.75e-01  1.61e-01  2.66e-01  5.70e-01  5.86e-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
  282.1306    -6.9790   0.0193    46.6552   141.6466         0.8337475     10.035 TRIG_00531223                 
 
Foreground time interval of the image:
  0.280   5.064 (delta_t =   4.784 [sec])
Background time interval of the image:
-239.288   0.280 (delta_t = 239.568 [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    0.280 sec. to    5.064 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.50906     ( -0.394653   0.33506 )
Norm@50keV  : 7.76598E-03    ( -0.00216841   0.00210312 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.34 using 59 PHA bins.
# Reduced chi-squared =         0.9533 for     57 degrees of freedom 
# Null hypothesis probability =   5.755166e-01
 
Photon flux (15-150 keV)    in 4.784 sec: 1.53431 ( -0.26393  0.26394 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.72513e-07 ( -7.62608e-08  7.87829e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    0.280 sec. to    5.064 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.49334     ( -0.508637   1.9391 )
Epeak [keV] : 18.9910      (   )
Norm@50keV  : 3.25989E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.03 using 59 PHA bins.
# Reduced chi-squared =         0.9470 for     56 degrees of freedom 
# Null hypothesis probability =   5.879339e-01
 
Photon flux (15-150 keV)    in 4.784 sec: 1.50360 ( -0.26636  0.26146 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

    1-s peak spectrum fit

    Power-law model
    Time interval is from    0.828 sec. to    1.828 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.98879     ( -0.444753   0.401971 )
Norm@50keV  : 1.36839E-02    ( -0.00393964   0.0038217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.02 using 59 PHA bins.
# Reduced chi-squared =          1.018 for     57 degrees of freedom 
# Null hypothesis probability =   4.373036e-01
 
Photon flux (15-150 keV)    in 1 sec: 2.04220 ( -0.54003  0.54287 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.26145e-07 ( -3.44111e-08  3.48232e-08 ) ergs/cm2
    Cutoff power-law model
    Time interval is from    0.828 sec. to    1.828 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.17891     ( -2.35477   4.79805 )
Epeak [keV] : 45.0711      ( -27.8136 -45.0135 )
Norm@50keV  : 0.207066    ( -0.218375   116.566 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.65 using 59 PHA bins.
# Reduced chi-squared =         0.9938 for     56 degrees of freedom 
# Null hypothesis probability =   4.879118e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.91070 ( -0.56922  0.5702 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.13849e-07 ( -3.50828e-08  3.77583e-08 ) ergs/cm2

    Time-resolved spectra




    Distribution

    T90 vs. Hardness ratio plot 

    T90                                   = 4.432 sec.
Hardness ratio (energy fluence ratio) = 0.702732489143

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

    S(15-50 keV)  = 2.472756e-07
S(50-150 keV) = 1.2524261e-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 = -8.308680870820799E-01, IMY = -6.574392750988901E-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:
-239.288000 0.280000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4659  35.3615    1.6  42.0 -144.6   2.2500   7.4    1.2	Her X-1                       
268.3185  -1.3738   12.7  49.9  161.1   0.5396   0.9    5.6	SW J1753.5-0127               
288.8074  10.9207    0.8  27.8  146.6   3.5398  15.1    1.6	GRS 1915+105                  
299.5901  35.2645    2.5   5.5 -144.8   0.7670   4.6    3.8	Cyg X-1                       
308.0777  40.9382    1.3   7.3  -59.5   1.6548   9.0    1.7	Cyg X-3                       
326.1782  38.3268   24.2  16.9   -3.2   0.0806   0.5    0.4	Cyg X-2                       
357.0289  24.8628    2.7  44.9   15.5   1.4292   4.2 ------	UNKNOWN                       
320.0592  34.6900    2.5  11.6    9.9   0.7552   4.6 ------	UNKNOWN                       
 11.4501  39.5664    2.8  51.6   -8.5   1.6644   4.1 ------	UNKNOWN                       
268.5747  54.6383    2.5  33.3 -111.7   1.3843   4.6 ------	UNKNOWN

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

    Time interval of the image:
0.280000 5.064000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3376  35.4228    7.9  42.1 -144.5  -0.0537  -1.5    7.6	Her X-1                       
268.3856  -1.4282    6.6  49.9  161.0  -0.1273  -1.7    1.8	SW J1753.5-0127               
288.6092  10.9856    5.8  27.8  147.1   0.0539   2.0   11.4	GRS 1915+105                  
299.3756  35.2374    9.6   5.6 -145.5  -0.0248  -1.2   10.7	Cyg X-1                       
308.0362  40.7796    7.5   7.1  -59.5  -0.0305  -1.5   10.9	Cyg X-3                       
326.3507  38.4177    8.4  17.0   -3.4  -0.0265  -1.4   10.2	Cyg X-2                       
282.1306  -6.9790    1.2  46.7  141.6   0.8337  10.0 ------	UNKNOWN                       
266.0249  -0.8453    3.0  51.1  163.8   0.3045   3.8 ------	UNKNOWN

    Post-slew image of 15-350 keV band 

    Time interval of the image:
115.812590 962.779600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9802 -15.6457    0.3  37.4 -118.6  37.8687  38.4    0.3	Sco X-1                       
254.4939  35.3110    8.4  49.6  -41.7   2.8230   1.4    2.6	Her X-1                       
256.0985 -37.8408    4.0  38.9 -158.4   2.0263   2.9    5.3	4U 1700-377                   
256.4499 -36.4328    3.2  37.7 -157.1   2.5687   3.6    0.9	GX 349+2                      
262.9990 -24.6882    3.7  25.5 -148.1   1.5051   3.1    3.5	GX 1+4                        
264.8585 -44.5203    2.7  40.5 -172.9   3.0188   4.3    6.5	4U 1735-44                    
268.3843  -1.3562    2.8  14.8  -80.3   2.1046   4.2    5.9	SW J1753.5-0127               
270.1656 -24.9612    4.3  21.3 -160.8   1.4013   2.7    9.6	GX 5-1                        
270.3262 -25.8038    5.1  22.0 -162.4   1.1723   2.3    3.9	GRS 1758-258                  
274.0163 -14.0335    0.9  10.7 -144.2   6.2312  12.7    0.6	GX 17+2                       
275.8995 -30.3668    3.4  24.1 -178.7   1.8076   3.4    1.3	H1820-303                     
284.9773 -24.8497    5.7  18.1  159.7   1.0464   2.0    5.3	HT1900.1-2455                 
288.8055  10.9580    0.4  19.1    8.5  13.0866  27.7    0.9	GRS 1915+105                  
299.5231  35.1537    7.6  45.2    8.3   1.4744   1.5    4.4	Cyg X-1                       
308.1378  41.0173    3.4  53.6   12.4   7.9357   3.4    4.1	Cyg X-3                       
262.9754 -33.8437    6.0  32.2 -161.2   1.0761   1.9    0.9	GX 354-0                      
277.0338 -58.1284    2.8  51.3  171.5   6.1931   4.2 ------	UNKNOWN                       
287.5919  -5.8076    1.8   5.6   66.5   3.1811   6.5 ------	UNKNOWN                       
285.8213  24.5501    3.1  31.7   -5.5   2.4092   3.8 ------	UNKNOWN                       
255.1362 -41.6646    1.9  42.2 -161.6   4.3242   6.1 ------	UNKNOWN                       
238.9440 -40.7395    2.2  51.1 -150.2   7.7050   5.3 ------	UNKNOWN                       
	UNKNOWN