GRB050819: 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: Wed Jan 22 20:52:03 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger151131
======================================================================

  Trigger: 00151131      Segment: 000

  BAT Trigger Time: 146161434.816   [s; MET]
      Trigger Stop: 146161461.696   [s; MET]
               UTC: 2005-08-19T16:23:55.132880    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 358.735497383504   Dec: 24.8535340564834  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.79
     Image Trigger?:     NO
     Rate S/N Ratio:     9.9498743710662  [ if not an image trigger ]
     Image S/N Ratio:    8.79

  Analysis Position:   [ source = BAT ]
    RA: 358.735497383504   Dec: 24.8535340564834  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 358.751657545976   Dec: 24.8705118605285  [deg; J2000]  
        { 23h 55m 00.4s , +24d 52' 13.8" }
         +/- 2.0651053722736 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.83206117663201 [arcmin] (formal 1-sigma fit error)
    SNR: 10.7944601618508
 
  Angular difference between the analysis and refined position is 1.345973 arcmin
 
  Partial Coding Fraction: 0.765625    [ including projection effects ]

  Duration
     T90: 37.7159999907017 +/- 7.33119826972135
        Measured from: -3.32800000905991
                   to: 34.3879999816418     [s; relative to TRIGTIME]
     T50: 18.2520000040531 +/- 5.40635663989368
        Measured from: 5.3759999871254
                   to: 23.6279999911785     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 9.50399997830391     
                   to: 10.5039999783039     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -7.216000020504     
                   to: 40.0839999914169     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.395149   0.340908   0.044823   0.013295
           0.034391   0.035265   0.030030   0.025407 [error]
 Peak      0.018571   0.015891   0.009983   0.011320
           0.004916   0.005094   0.004321   0.003732 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   47.300   -7.216   40.084
T90    37.716   -3.328   34.388
T50    18.252    5.376   23.628
Peak    1.000    9.504   10.504
 
 
====== 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      -2.637    -0.294      0.262       -           -               -         7.06e-04     -1.57e-04          1.59e-04      48.070   57
CPL     -0.488    -1.363      2.070       23.318     -21.372         6.050      1.81e-02     -1.81e-02          4.41e-01      41.350   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      -1.817     -0.717     0.609       -           -               -         2.85e-03     -1.16e-03          1.02e-03      56.560   57
CPL     -2.077     -1.310     1.082       31.455      N/A           N/A         1.95e-03        N/A               N/A         55.950   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   1.26e-07  1.17e-07  7.50e-08  7.43e-08  3.48e-07  3.92e-07   erg/cm2
      90%_error_low -1.78e-08 -1.76e-08 -2.14e-08 -3.32e-08 -5.33e-08 -7.18e-08   erg/cm2
      90%_error_hi   1.79e-08  1.72e-08  2.38e-08  4.87e-08  5.59e-08  8.32e-08   erg/cm2
Peak flux       PL   1.59e-01  1.33e-01  7.54e-02  6.34e-02  3.95e-01  4.31e-01   ph/cm2/s
      90%_error_low -7.17e-02 -3.93e-02 -3.86e-02 -4.64e-02 -1.17e-01 -1.31e-01   ph/cm2/s
      90%_error_hi   7.68e-02  3.92e-02  3.81e-02  8.93e-02  1.17e-01  1.33e-01   ph/cm2/s
 
Fluence        CPL   1.19e-07  1.39e-07  4.52e-08  2.49e-09  3.05e-07  3.05e-07   erg/cm2
      90%_error_low -2.00e-08 -2.37e-08 -2.46e-08    N/A    -4.54e-08 -4.56e-08   erg/cm2
      90%_error_hi   1.96e-08  2.43e-08  3.16e-08    N/A     5.24e-08  5.45e-08   erg/cm2
Peak flux      CPL   1.45e-01  1.06e-01  5.58e-02  4.92e-02  3.98e-01  4.35e-01   ph/cm2/s
      90%_error_low     N/A   -5.98e-02 -3.15e-02 -2.83e-02 -1.20e-01 -1.37e-01   ph/cm2/s
      90%_error_hi      N/A    6.04e-02  2.73e-02  2.13e-02  1.14e-01  1.15e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  358.7517    24.8705   0.0178    20.6516  -113.9978         0.7327576     10.794 TRIG_00151131                 
 
Foreground time interval of the image:
 -7.216  40.084 (delta_t =  47.300 [sec])
Background time interval of the image:
-299.816  -7.216 (delta_t = 292.600 [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   -7.216 sec. to   40.084 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.63682     ( -0.29381   0.261606 )
Norm@50keV  : 7.06398E-04    ( -0.000156998   0.000159246 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.07 using 59 PHA bins.
# Reduced chi-squared =         0.8434 for     57 degrees of freedom 
# Null hypothesis probability =   7.941485e-01
 
Photon flux (15-150 keV)    in 47.3 sec: 0.151290 ( -0.018349  0.018357 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.48049e-07 ( -5.3308e-08  5.5876e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -7.216 sec. to   40.084 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.48808     ( -1.36551   2.06835 )
Epeak [keV] : 23.3179      ( -21.3976 6.02428 )
Norm@50keV  : 1.81330E-02    ( -0.0183863   0.440327 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.35 using 59 PHA bins.
# Reduced chi-squared =         0.7384 for     56 degrees of freedom 
# Null hypothesis probability =   9.282342e-01
 
Photon flux (15-150 keV)    in 47.3 sec: 0.151276 ( -0.018271  0.018377 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.0519e-07 ( -4.54312e-08  5.23961e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    9.504 sec. to   10.504 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.81651     ( -0.717126   0.609304 )
Norm@50keV  : 2.84842E-03    ( -0.00115969   0.00101735 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.56 using 59 PHA bins.
# Reduced chi-squared =         0.9922 for     57 degrees of freedom 
# Null hypothesis probability =   4.916281e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.395070 ( -0.116898  0.116889 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.62114e-08 ( -9.80286e-09  1.02741e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    9.504 sec. to   10.504 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.35308     ( -1.03144   1.36008 )
Epeak [keV] : 127.822      (   )
Norm@50keV  : 1.46525E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.57 using 59 PHA bins.
# Reduced chi-squared =         0.9923 for     56 degrees of freedom 
# Null hypothesis probability =   4.912038e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.398249 ( -0.120245  0.114004 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.18328e-08 ( -1.24037e-08  1.00723e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 37.716 sec.
Hardness ratio (energy fluence ratio) = 0.643176057811

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

S(15-50 keV)  = 2.422859e-07
S(50-150 keV) = 1.0577525e-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 = -1.532870115865904E-01, IMY = 3.443242978496762E-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:
-299.816000 -7.216000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5820  35.2055    0.9  55.4  174.2  10.0228  12.5    0.5	Cyg X-1                       
308.0498  40.8709   10.1  51.7 -175.9   0.5339   1.1    5.6	Cyg X-3                       
326.1837  38.2959    3.1  39.4 -166.0   0.8597   3.7    1.6	Cyg X-2                       
347.0113 -13.1931    2.4  19.3   55.6   0.8687   4.9 ------	UNKNOWN                       
312.3129  22.5361    2.2  40.6  163.1   1.5243   5.2 ------	UNKNOWN                       
 25.9530 -23.7288    3.1  45.3   -3.3   1.1805   3.8 ------	UNKNOWN                       

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

Time interval of the image:
-7.216000 40.084000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5612  35.2099    4.7  55.4  174.2  -0.7579  -2.5    1.5	Cyg X-1                       
308.1314  40.9392    7.7  51.7 -175.8   0.2357   1.5    1.3	Cyg X-3                       
326.2988  38.2324    8.8  39.3 -166.0   0.1136   1.3    8.0	Cyg X-2                       
340.0761  -1.2234    2.1  12.7  101.7   0.3352   5.4 ------	UNKNOWN                       
 30.7329 -33.6243    2.6  54.6    3.7   1.1122   4.4 ------	UNKNOWN                       
329.3315  21.9454    2.4  26.2  175.0   0.3175   4.8 ------	UNKNOWN                       
358.7516  24.8705    1.1  20.7 -114.0   0.7326  10.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
125.084590 302.215000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
299.5652  35.1778    2.3  51.5  165.2   2.2156   5.0    1.9	Cyg X-1                       
308.1363  40.9661    2.3  44.7  172.9   1.1545   5.0    1.4	Cyg X-3                       
326.2069  38.3354    3.5  30.6  172.9   0.4814   3.3    1.9	Cyg X-2                       
317.3130  26.9081    3.0  37.2  151.3   0.7545   3.8 ------	UNKNOWN                       
 44.0631  -9.1827    3.2  55.7   -9.3   1.6383   3.6 ------	UNKNOWN                       
292.6896  65.1683    3.0  57.6 -158.2   2.7539   3.9 ------	UNKNOWN