GRB151215A: 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 Mar 13 22:04:06 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger667392
======================================================================

  Trigger: 00667392      Segment: 000

  BAT Trigger Time: 471841304.512   [s; MET]
      Trigger Stop: 471841305.024   [s; MET]
               UTC: 2015-12-15T03:01:28.957040    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 93.5948780255951   Dec: 35.5094452220509  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.38
     Image Trigger?:     NO
     Rate S/N Ratio:     13.4164078649987  [ if not an image trigger ]
     Image S/N Ratio:    8.38

  Analysis Position:   [ source = BAT ]
    RA: 93.5948780255951   Dec: 35.5094452220509  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 93.6220121456678   Dec: 35.5311972156442  [deg; J2000]  
        { 06h 14m 29.3s , +35d 31' 52.3" }
         +/- 2.7617075848905 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.23891785382886 [arcmin] (formal 1-sigma fit error)
    SNR: 7.12630709045457
 
  Angular difference between the analysis and refined position is 1.859888 arcmin
 
  Partial Coding Fraction: 0.515625    [ including projection effects ]

  Duration
     T90: 17.8479999899864 +/- 1.01371396706698
        Measured from: -15.0800000429153
                   to: 2.76799994707108     [s; relative to TRIGTIME]
     T50: 13.4359999895096 +/- 12.6524377315551
        Measured from: -12.7880000472069
                   to: 0.647999942302704     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.164000034332275     
                   to: 0.835999965667725     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -15.460000038147     
                   to: 3.12799996137619     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.234536   0.215552   0.108779   0.021743
           0.035345   0.036595   0.031921   0.026498 [error]
 Peak      0.037885   0.087559   0.067219   0.008438
           0.008981   0.009913   0.009055   0.006769 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   18.588  -15.460    3.128
T90    17.848  -15.080    2.768
T50    13.436  -12.788    0.648
Peak    1.000   -0.164    0.836
 
 
====== 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      -1.990    -0.344      0.312       -           -               -         1.80e-03     -4.27e-04          4.14e-04      70.280   57
CPL     -1.095    -1.090      2.055       39.093      N/A           N/A         6.32e-03        N/A               N/A         68.950   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      -1.427     -0.218     0.215       -           -               -         1.29e-02     -1.92e-03          1.91e-03      66.710   57
CPL      0.452     -1.074     1.399       65.239     -11.341        24.403      1.16e-01     -1.16e-01          4.40e-01      56.330   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   6.77e-08  9.25e-08  9.32e-08  1.70e-07  3.08e-07  4.24e-07   erg/cm2
      90%_error_low -1.59e-08 -1.70e-08 -2.87e-08 -8.36e-08 -6.75e-08 -1.23e-07   erg/cm2
      90%_error_hi   1.63e-08  1.69e-08  3.01e-08  1.25e-07  7.02e-08  1.55e-07   erg/cm2
Peak flux       PL   4.97e-01  5.22e-01  3.88e-01  4.67e-01  1.59e+00  1.87e+00   ph/cm2/s
      90%_error_low -1.10e-01 -8.01e-02 -6.85e-02 -1.41e-01 -2.32e-01 -2.78e-01   ph/cm2/s
      90%_error_hi   1.16e-01  7.97e-02  6.81e-02  1.71e-01  2.33e-01  2.81e-01   ph/cm2/s
 
Fluence        CPL   6.50e-08  1.04e-07  8.50e-08  3.63e-08  2.79e-07  2.90e-07   erg/cm2
      90%_error_low -1.72e-08 -2.30e-08 -4.40e-08    N/A    -7.25e-08    N/A      erg/cm2
      90%_error_hi   1.72e-08  2.50e-08  3.57e-08    N/A     8.16e-08    N/A      erg/cm2
Peak flux      CPL   3.60e-01  6.26e-01  4.55e-01  1.09e-01  1.53e+00  1.55e+00   ph/cm2/s
      90%_error_low -1.28e-01 -1.04e-01 -8.82e-02     N/A   -2.34e-01 -2.44e-01   ph/cm2/s
      90%_error_hi   1.37e-01  1.08e-01  8.95e-02     N/A    2.35e-01  2.53e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   93.6220    35.5312   0.0269    28.6473    47.6567         0.5469556      7.126 TRIG_00667392                 
 
Foreground time interval of the image:
-15.460   3.128 (delta_t =  18.588 [sec])
Background time interval of the image:
-59.811 -15.460 (delta_t =  44.351 [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  -15.460 sec. to    3.128 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.98956     ( -0.343733   0.312456 )
Norm@50keV  : 1.79848E-03    ( -0.000427002   0.00041375 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          70.28 using 59 PHA bins.
# Reduced chi-squared =          1.233 for     57 degrees of freedom 
# Null hypothesis probability =   1.112693e-01
 
Photon flux (15-150 keV)    in 18.59 sec: 0.268505 ( -0.048201  0.0482 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.08218e-07 ( -6.75166e-08  7.02148e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -15.460 sec. to    3.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.09512     ( -1.09177   2.05266 )
Epeak [keV] : 39.0931      (   )
Norm@50keV  : 6.32491E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          68.95 using 59 PHA bins.
# Reduced chi-squared =          1.231 for     56 degrees of freedom 
# Null hypothesis probability =   1.145580e-01
 
Photon flux (15-150 keV)    in 18.59 sec: 0.262298 ( -0.048672  0.048983 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.78869e-07 ( -7.254e-08  8.16099e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.164 sec. to    0.836 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.42737     ( -0.217519   0.214755 )
Norm@50keV  : 1.29492E-02    ( -0.00191838   0.00191136 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          66.71 using 59 PHA bins.
# Reduced chi-squared =          1.170 for     57 degrees of freedom 
# Null hypothesis probability =   1.777593e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.58711 ( -0.23249  0.23275 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.24454e-07 ( -1.99339e-08  2.01399e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.164 sec. to    0.836 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.452103     ( -1.07351   1.39915 )
Epeak [keV] : 65.2387      ( -11.3414 24.4028 )
Norm@50keV  : 0.115866    ( -0.115865   0.440154 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.33 using 59 PHA bins.
# Reduced chi-squared =          1.006 for     56 degrees of freedom 
# Null hypothesis probability =   4.624742e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.53016 ( -0.23415  0.23494 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.14839e-07 ( -1.99185e-08  2.07111e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 17.848 sec.
Hardness ratio (energy fluence ratio) = 1.00732584297

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

S(15-50 keV)  = 1.6023533e-07
S(50-150 keV) = 1.4798569e-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 = 3.679645698738787E-01, IMY = -4.037742182533751E-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:
-59.811400 -15.460000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6396  21.9893    1.0  34.4   76.8   1.9109  11.4    1.6	Crab                          
132.1162  46.2794    2.2  46.0    4.3   0.7260   5.2 ------	UNKNOWN                       
136.9102  68.5761    2.2  39.2  -27.5   0.5532   5.2 ------	UNKNOWN                       

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

Time interval of the image:
-15.460000 3.128000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.7274  22.0745  130.7  34.3   76.6   0.0111   0.1    6.4	Crab                          
 39.6392   5.7473    2.6  48.2  145.7   1.0848   4.4 ------	UNKNOWN                       
 93.6220  35.5312    1.6  28.6   47.7   0.5470   7.1 ------	UNKNOWN                       
133.0173  48.2503    1.9  45.5    1.6   0.6146   6.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
151.988600 962.627100
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6277  22.0124    0.3  16.0   83.6  32.6461  46.1    0.3	Crab                          
  6.2042  65.2752    3.1  57.1 -161.7  12.9011   3.7 ------	UNKNOWN                       
150.8424  13.6545    3.0  55.6  -34.0  19.6259   3.9 ------	UNKNOWN                       
150.9906  23.2802    5.1  50.8  -44.4  11.2728   2.2 ------	UNKNOWN