GRB130508A: Summary Image Light curves Spectra Distribution Others

Analysis Summary

Notes:

• 1) No attempt has been made to eliminate the non-significant decimal places.
• 2) This batgrbproduct analysis is done using the HEASARC data.
• 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.

======================================================================
                  BAT GRB EVENT DATA PROCESSING REPORT
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Sun Jan 12 03:32:02 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger555413
======================================================================

  Trigger: 00555413      Segment: 000

  BAT Trigger Time: 389725744   [s; MET]
      Trigger Stop: 389725808   [s; MET]
               UTC: 2013-05-08T17:08:53.468120    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 305.312531851058   Dec: 34.9494108084652  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.58
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    10.58

  Analysis Position:   [ source = BAT ]
    RA: 305.312531851058   Dec: 34.9494108084652  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 305.355067905114   Dec: 34.9773647885541  [deg; J2000]  
        { 20h 21m 25.2s , +34d 58' 38.5" }
         +/- 1.91253012898756 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.857067080276658 [arcmin] (formal 1-sigma fit error)
    SNR: 12.0453889818615
 
  Angular difference between the analysis and refined position is 2.680987 arcmin
 
  Partial Coding Fraction: 0.609375    [ including projection effects ]

  Duration
     T90: 42.9120000600815 +/- 10.1276240195608
        Measured from: 11.3519999980927
                   to: 54.2640000581741     [s; relative to TRIGTIME]
     T50: 22.6080000400543 +/- 5.75297350205848
        Measured from: 15.2400000095367
                   to: 37.8480000495911     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 11.0519999861717     
                   to: 12.0519999861717     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 10.1520000100136     
                   to: 58.727999985218     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.391673   0.466718   0.215761   0.045362
           0.051705   0.053582   0.047808   0.044991 [error]
 Peak      0.018086   0.029338   0.026861   0.009417
           0.007364   0.007743   0.007004   0.006760 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   48.576   10.152   58.728
T90    42.912   11.352   54.264
T50    22.608   15.240   37.848
Peak    1.000   11.052   12.052
 
 
====== 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      -1.845    -0.256      0.243       -           -               -         1.38e-03     -2.35e-04          2.29e-04      57.550   57
CPL     -1.185    -0.989      1.646       48.455      N/A           N/A         3.44e-03        N/A               N/A         56.680   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      -1.272     -0.533     0.563       -           -               -         5.03e-03     -1.47e-03          1.46e-03      41.780   57
CPL     -1.270     -0.534     0.568     9999.310    -9999.310      -9999.310      5.05e-03     -1.48e-03          4.50e-02      41.780   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   1.18e-07  1.76e-07  1.96e-07  4.12e-07  6.14e-07  9.02e-07   erg/cm2
      90%_error_low -2.22e-08 -2.40e-08 -4.44e-08 -1.59e-07 -1.03e-07 -2.13e-07   erg/cm2
      90%_error_hi   2.27e-08  2.40e-08  4.57e-08  2.17e-07  1.06e-07  2.60e-07   erg/cm2
Peak flux       PL   1.66e-01  1.92e-01  1.59e-01  2.21e-01  5.97e-01  7.38e-01   ph/cm2/s
      90%_error_low -8.41e-02 -6.54e-02 -5.71e-02 -1.30e-01 -1.76e-01 -2.22e-01   ph/cm2/s
      90%_error_hi   9.69e-02  6.21e-02  5.54e-02  2.21e-01  1.77e-01  2.35e-01   ph/cm2/s
 
Fluence        CPL   1.14e-07  1.91e-07  1.84e-07  1.19e-07  5.60e-07  6.08e-07   erg/cm2
      90%_error_low -2.44e-08 -4.09e-08 -6.66e-08    N/A    -1.26e-07 -1.71e-07   erg/cm2
      90%_error_hi   2.41e-08  3.84e-08  5.35e-08    N/A     1.40e-07  3.61e-07   erg/cm2
Peak flux      CPL   1.69e-01  1.90e-01  1.57e-01  2.60e-01  6.00e-01  7.58e-01   ph/cm2/s
      90%_error_low -9.45e-02 -6.58e-02 -5.73e-02     N/A   -1.85e-01 -3.15e-01   ph/cm2/s
      90%_error_hi   8.79e-02  7.42e-02  6.24e-02     N/A    1.79e-01  2.01e-01   ph/cm2/s
 
======================================================================

Image

Pre-slew 15.0-350.0 keV image (Event data)

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  305.3551    34.9774   0.0159    20.9843    85.9116         1.3505782     12.045 TRIG_00555413                 
 
Foreground time interval of the image:
 10.152  58.728 (delta_t =  48.576 [sec])
Background time interval of the image:
-567.599 -553.259 (delta_t =  14.340 [sec])
-239.000  10.152 (delta_t = 249.152 [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

Other quick-look light curves:

• 64 ms binning (zoomed)
• 16 ms binning (zoomed)
• 8 ms binning (zoomed)
• 2 ms binning (zoomed)
• SN=5 or 10 s binning (full-time range)
• Raw light curve

Spectra

Notes:

• 1) The fitting includes the systematic errors.
• 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
• 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.

Time averaged spectrum fit using the average DRM

Power-law model

Time interval is from   10.152 sec. to   58.728 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.84532     ( -0.256309   0.24275 )
Norm@50keV  : 1.37536E-03    ( -0.000234634   0.000228556 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.55 using 59 PHA bins.
# Reduced chi-squared =          1.010 for     57 degrees of freedom 
# Null hypothesis probability =   4.545541e-01
 
Photon flux (15-150 keV)    in 48.58 sec: 0.192966 ( -0.026128  0.026128 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.14493e-07 ( -1.02968e-07  1.06328e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   10.152 sec. to   58.728 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.18523     ( -0.990018   1.64526 )
Epeak [keV] : 48.4551      (   )
Norm@50keV  : 3.44342E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.68 using 59 PHA bins.
# Reduced chi-squared =          1.012 for     56 degrees of freedom 
# Null hypothesis probability =   4.494813e-01
 
Photon flux (15-150 keV)    in 48.58 sec: 0.188132 ( -0.027569  0.027562 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.60322e-07 ( -1.25864e-07  1.40468e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   11.052 sec. to   12.052 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.27152     ( -0.53259   0.562685 )
Norm@50keV  : 5.02853E-03    ( -0.00146726   0.00146044 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.78 using 59 PHA bins.
# Reduced chi-squared =         0.7329 for     57 degrees of freedom 
# Null hypothesis probability =   9.348790e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.596888 ( -0.176167  0.176825 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.00507e-08 ( -1.62963e-08  1.67898e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   11.052 sec. to   12.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.26982     ( -0.533735   0.567986 )
Epeak [keV] : 9999.31      ( -9999.36 -9999.36 )
Norm@50keV  : 5.04942E-03    ( -0.00147807   0.0450326 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.78 using 59 PHA bins.
# Reduced chi-squared =         0.7460 for     56 degrees of freedom 
# Null hypothesis probability =   9.212593e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.599622 ( -0.184528  0.178677 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.08382e-08 ( -2.16666e-08  1.91976e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 42.912 sec.
Hardness ratio (energy fluence ratio) = 1.11321718982

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

S(15-50 keV)  = 2.940054e-07
S(50-150 keV) = 3.204906e-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 = 2.734536579764521E-02, IMY = -3.825728259447613E-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:
-567.599400 -553.259400
-239.000000 10.152000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.8091  35.1423    4.3  25.0   91.6   0.8018   2.7   11.3	Cyg X-1                       
308.0677  40.9408    1.3  16.9  100.9   2.0216   8.6    2.1	Cyg X-3                       
326.0207  38.1469    0.0   5.5   50.0   0.4481   2.3   12.7	Cyg X-2                       
342.8144  20.3716    2.6  24.2  -20.9   0.9573   4.4 ------	UNKNOWN                       
 95.2446  74.1356    3.2  57.8 -156.7   5.1245   3.6 ------	UNKNOWN                       

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

Time interval of the image:
10.152000 58.728000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.4789  35.0519   11.7  25.2   91.7   0.1303   1.0   10.5	Cyg X-1                       
307.8967  40.9504   10.8  17.0  101.1  -0.0982  -1.1    9.7	Cyg X-3                       
326.1504  38.2376    8.0   5.3   49.7  -0.1231  -1.4    5.1	Cyg X-2                       
305.3550  34.9773    1.0  21.0   85.9   1.3506  12.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
114.900600 570.400610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3255  35.2552   60.8  41.3  126.0   0.2557   0.2    8.3	Her X-1                       
288.8238  10.9324    1.0  28.3   56.3   5.7385  11.4    1.7	GRS 1915+105                  
299.5787  35.1876    1.7   4.7  114.8   2.1317   6.7    1.0	Cyg X-1                       
308.0659  40.9587    1.3   6.4 -140.9   3.1267   9.0    2.0	Cyg X-3                       
326.2106  38.3247    6.1  17.0  -87.3   0.6709   1.9    1.8	Cyg X-2                       
225.8305  66.3405    2.8  54.2  171.1   7.3603   4.2 ------	UNKNOWN                       
318.8863 -19.9374    2.2  56.4    4.9   8.6858   5.2 ------	UNKNOWN                       
235.6136  75.5145    2.5  51.3 -177.3   4.5656   4.6 ------	UNKNOWN                       
208.7522  78.1105    3.7  57.2 -173.9   5.9296   3.1 ------	UNKNOWN                       
336.5224 -14.6470    3.1  57.7  -16.1   5.5957   3.7 ------	UNKNOWN                       
118.7408  86.2517    5.1  58.8 -159.3   6.3822   2.2 ------	UNKNOWN                       
354.8777  75.3146    3.2  46.5 -144.3   2.8955   3.6 ------	UNKNOWN                       
351.2727  12.4823    3.0  47.1  -53.0   6.4597   3.9 ------	UNKNOWN