GRB051227

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 19:17:29 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger174738
======================================================================

  Trigger: 00174738      Segment: 000

  BAT Trigger Time: 157399635.968   [s; MET]
      Trigger Stop: 157399636.992   [s; MET]
               UTC: 2005-12-27T18:07:16.047360    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 125.270470889684   Dec: 31.9290015448698  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.59
     Image Trigger?:     NO
     Rate S/N Ratio:     22.8254244210267  [ if not an image trigger ]
     Image S/N Ratio:    10.59

  Analysis Position:   [ source = BAT ]
    RA: 125.270470889684   Dec: 31.9290015448698  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 125.23772898897   Dec: 31.9516727398996  [deg; J2000]  
        { 08h 20m 57.1s , +31d 57' 06.0" }
         +/- 2.14398761662358 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.11185493676384 [arcmin] (formal 1-sigma fit error)
    SNR: 10.2316035713982
 
  Angular difference between the analysis and refined position is 2.151630 arcmin
 
  Partial Coding Fraction: 0.9765625    [ including projection effects ]

  Duration
     T90: 115.400000035763 +/- 14.9441675577194
        Measured from: 0.127999991178513
                   to: 115.528000026941     [s; relative to TRIGTIME]
     T50: 67.4239999949932 +/- 20.5635553259871
        Measured from: 6.4360000193119
                   to: 73.8600000143051     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.00400000810623169     
                   to: 0.995999991893768     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.84799998998642     
                   to: 122.731999993324     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.325336   0.431133   0.301611   0.084727
           0.049472   0.051529   0.045519   0.040656 [error]
 Peak      0.028849   0.036106   0.046235   0.014614
           0.004844   0.005307   0.004992   0.004255 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  123.580   -0.848  122.732
T90   115.400    0.128  115.528
T50    67.424    6.436   73.860
Peak    1.000   -0.004    0.996
 
 
====== 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      -1.415    -0.237      0.237       -           -               -         5.91e-04     -8.05e-05          7.97e-05      51.790   57
CPL     -1.413    -0.898      0.416     9999.190    -9999.190      -9999.190      5.93e-04     -4.37e-04          6.47e-04      51.790   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      -1.001     -0.227     0.236       -           -               -         8.22e-03     -1.04e-03          1.04e-03      61.950   57
CPL     -0.933     -0.295     0.699      884.989    -884.989      -884.989      8.84e-03     -1.61e-03          8.47e-03      62.070   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   8.62e-08  1.67e-07  2.50e-07  8.12e-07  7.04e-07  1.32e-06   erg/cm2
      90%_error_low -1.90e-08 -2.30e-08 -4.48e-08 -2.73e-07 -1.08e-07 -3.14e-07   erg/cm2
      90%_error_hi   1.99e-08  2.27e-08  4.46e-08  3.61e-07  1.09e-07  3.88e-07   erg/cm2
Peak flux       PL   2.10e-01  2.85e-01  2.85e-01  5.15e-01  9.47e-01  1.29e+00   ph/cm2/s
      90%_error_low -5.38e-02 -4.61e-02 -3.99e-02 -1.43e-01 -1.22e-01 -1.79e-01   ph/cm2/s
      90%_error_hi   5.87e-02  4.50e-02  3.93e-02  1.78e-01  1.22e-01  1.88e-01   ph/cm2/s
 
Fluence        CPL   8.70e-08  1.65e-07  2.50e-07  8.16e-07  7.09e-07  1.33e-06   erg/cm2
      90%_error_low    N/A       N/A    -4.48e-08    N/A    -1.26e-07 -6.61e-07   erg/cm2
      90%_error_hi     N/A       N/A     4.46e-08    N/A     1.15e-07  1.56e-07   erg/cm2
Peak flux      CPL   2.17e-01  2.82e-01  2.81e-01  5.11e-01  9.52e-01  1.37e+00   ph/cm2/s
      90%_error_low     N/A       N/A       N/A       N/A   -1.58e-01 -3.79e-01   ph/cm2/s
      90%_error_hi      N/A       N/A       N/A       N/A    1.48e-01  9.60e-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
  125.2377    31.9517   0.0188    20.9660   -27.7801         0.4036440     10.232 TRIG_00174738                 
 
Foreground time interval of the image:
 -0.848  18.733 (delta_t =  19.581 [sec])
Background time interval of the image:
-299.968  -0.848 (delta_t = 299.120 [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:

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   -0.848 sec. to  122.732 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.415     ( -0.237065   0.237433 )
Norm@50keV  : 5.91471E-04    ( -8.04589e-05   7.96927e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.79 using 59 PHA bins.
# Reduced chi-squared =         0.9085 for     57 degrees of freedom 
# Null hypothesis probability =   6.704156e-01
 
Photon flux (15-150 keV)    in 123.6 sec: 7.22807E-02 ( -0.0095379  0.0095466 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.04349e-07 ( -1.07509e-07  1.09415e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.848 sec. to  122.732 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.41286     ( -0.898136   0.41609 )
Epeak [keV] : 9999.19      ( -9999.36 -9999.36 )
Norm@50keV  : 5.93435E-04    ( -0.00043735   0.00064669 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          51.79 using 59 PHA bins.
# Reduced chi-squared =         0.9249 for     56 degrees of freedom 
# Null hypothesis probability =   6.347482e-01
 
Photon flux (15-150 keV)    in 123.6 sec: 7.25490E-02 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.08758e-07 ( -1.25651e-07  1.14998e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from   -0.004 sec. to    0.996 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.00093     ( -0.227112   0.235533 )
Norm@50keV  : 8.22481E-03    ( -0.00104457   0.00104058 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.95 using 59 PHA bins.
# Reduced chi-squared =          1.087 for     57 degrees of freedom 
# Null hypothesis probability =   3.041125e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.946959 ( -0.122155  0.122491 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.89181e-08 ( -1.23549e-08  1.24497e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.004 sec. to    0.996 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.995326     ( -0.293216   0.701456 )
Epeak [keV] : 9999.36      ( -9999.36 -9999.36 )
Norm@50keV  : 8.27416E-03    ( -0.00103703   0.00904117 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          61.96 using 59 PHA bins.
# Reduced chi-squared =          1.106 for     56 degrees of freedom 
# Null hypothesis probability =   2.720997e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.952261 ( -0.158492  0.147559 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.95241e-08 ( -1.68265e-08  1.57302e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 115.4 sec.
Hardness ratio (energy fluence ratio) = 1.50006562447

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

S(15-50 keV)  = 2.5306271e-07
S(50-150 keV) = 4.512906e-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 = 3.390189792628797E-01, IMY = 1.785939202094247E-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:
-299.968000 -0.848000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6319  22.0145    0.2  18.4  124.2  13.0823  62.6    0.1	Crab                          
 90.4635  -5.1203    2.3  39.2   82.1   4.1617   4.9 ------	UNKNOWN                       
139.2812  33.3190    2.5  32.4  -35.2   1.1813   4.6 ------	UNKNOWN                       
155.8220  22.3487    2.7  49.7  -26.2   2.0541   4.3 ------	UNKNOWN

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

Time interval of the image:
-0.848000 18.732600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7894  22.0936    4.7  18.2  124.1   0.1088   2.4    9.9	Crab                          
 34.3947  40.6634    2.4  52.2 -174.9   0.4531   4.7 ------	UNKNOWN                       
125.2377  31.9517    1.1  21.0  -27.8   0.4038  10.2 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
80.732600 302.106100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6322  22.0199    0.7  38.1   97.2   9.1635  16.2    0.3	Crab                          
177.9342  43.0761    3.0  42.5 -109.1   2.6048   3.9 ------	UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

Mask shadow pattern

Spacecraft aspect plot

Bright source in the pre-burst/pre-slew/post-slew images

Pre-burst image of 15-350 keV band

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

Post-slew image of 15-350 keV band

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