GRB130131A: 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 05:50:27 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger547407
======================================================================

  Trigger: 00547407      Segment: 000

  BAT Trigger Time: 381333392.192   [s; MET]
      Trigger Stop: 381333393.216   [s; MET]
               UTC: 2013-01-31T13:56:22.028180    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 171.108082478216   Dec: 48.0695104914022  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    9.89
     Image Trigger?:     NO
     Rate S/N Ratio:     13.228756555323  [ if not an image trigger ]
     Image S/N Ratio:    9.89

  Analysis Position:   [ source = BAT ]
    RA: 171.108082478216   Dec: 48.0695104914022  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 171.092733997921   Dec: 48.075575385707  [deg; J2000]  
        { 11h 24m 22.3s , +48d 04' 32.1" }
         +/- 2.20501738668926 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.00971025974905 [arcmin] (formal 1-sigma fit error)
    SNR: 9.8294627789625
 
  Angular difference between the analysis and refined position is 0.714887 arcmin
 
  Partial Coding Fraction: 0.9765625    [ including projection effects ]

  Duration
     T90: 51.5239999294281 +/- 2.51219424154756
        Measured from: -0.295999944210052
                   to: 51.227999985218     [s; relative to TRIGTIME]
     T50: 45.4199999570847 +/- 2.64419366495476
        Measured from: 1.14000004529953
                   to: 46.5600000023842     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.0399999618530273     
                   to: 0.960000038146973     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.951999962329865     
                   to: 52.0680000185966     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.267691   0.235574   0.121162   0.014423
           0.034899   0.035785   0.030948   0.026430 [error]
 Peak      0.027968   0.046365   0.018981   0.004544
           0.005168   0.005349   0.004660   0.003706 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   53.020   -0.952   52.068
T90    51.524   -0.296   51.228
T50    45.420    1.140   46.560
Peak    1.000   -0.040    0.960
 
 
====== 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      -2.134    -0.337      0.299       -           -               -         6.20e-04     -1.45e-04          1.40e-04      47.360   57
CPL     -1.513    -0.600      1.592       30.760     -24.671       -30.760      1.47e-03     -1.47e-03          1.26e-02      46.620   56
 
 
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
 
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      -1.782     -0.259     0.241       -           -               -         5.40e-03     -1.02e-03          9.99e-04      72.940   57
CPL      1.226     -1.491     2.102       43.834      -6.207         8.768      2.99e-01     -2.99e-01          4.82e+00      57.920   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   7.64e-08  9.56e-08  8.71e-08  1.38e-07  3.06e-07  3.97e-07   erg/cm2
      90%_error_low -1.52e-08 -1.61e-08 -2.66e-08 -6.74e-08 -6.12e-08 -1.05e-07   erg/cm2
      90%_error_hi   1.56e-08  1.57e-08  2.82e-08  1.00e-07  6.41e-08  1.31e-07   erg/cm2
Peak flux       PL   2.92e-01  2.48e-01  1.44e-01  1.25e-01  7.39e-01  8.10e-01   ph/cm2/s
      90%_error_low -6.13e-02 -3.97e-02 -3.37e-02 -4.70e-02 -1.18e-01 -1.33e-01   ph/cm2/s
      90%_error_hi   6.35e-02  3.97e-02  3.44e-02  6.10e-02  1.18e-01  1.35e-01   ph/cm2/s
 
Fluence        CPL   7.36e-08  1.03e-07  8.23e-08  4.55e-08  2.87e-07  3.05e-07   erg/cm2
      90%_error_low -1.68e-08 -1.99e-08 -3.35e-08 -4.07e-08 -6.42e-08 -8.04e-08   erg/cm2
      90%_error_hi   1.64e-08  2.25e-08  3.12e-08  1.91e-07  7.34e-08  2.15e-07   erg/cm2
Peak flux      CPL   2.22e-01  3.43e-01  1.33e-01  7.02e-03  7.05e-01  7.06e-01   ph/cm2/s
      90%_error_low -7.22e-02 -5.93e-02 -4.80e-02 -7.02e-03 -1.15e-01 -1.15e-01   ph/cm2/s
      90%_error_hi   7.44e-02  6.13e-02  4.72e-02  2.09e-02  1.16e-01  1.17e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  171.0927    48.0756   0.0196     9.7529   -87.2823         0.3914883      9.829 TRIG_00547407                 
 
Foreground time interval of the image:
 -0.952  18.509 (delta_t =  19.461 [sec])
Background time interval of the image:
-239.192  -0.952 (delta_t = 238.240 [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   -0.952 sec. to   52.068 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.13423     ( -0.337227   0.299325 )
Norm@50keV  : 6.19532E-04    ( -0.000144508   0.000139676 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.36 using 59 PHA bins.
# Reduced chi-squared =         0.8309 for     57 degrees of freedom 
# Null hypothesis probability =   8.149168e-01
 
Photon flux (15-150 keV)    in 53.02 sec: 9.91569E-02 ( -0.0154338  0.0154371 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.06337e-07 ( -6.1245e-08  6.40959e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.952 sec. to   52.068 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.51273     ( -0.600003   1.59225 )
Epeak [keV] : 30.7599      ( -24.6707 -30.7591 )
Norm@50keV  : 1.46876E-03    ( -0.00146868   0.0126102 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.62 using 59 PHA bins.
# Reduced chi-squared =         0.8325 for     56 degrees of freedom 
# Null hypothesis probability =   8.099081e-01
 
Photon flux (15-150 keV)    in 53.02 sec: 9.73196E-02 ( -0.0157026  0.0158024 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.87263e-07 ( -6.42242e-08  7.33569e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.040 sec. to    0.960 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.78177     ( -0.257282   0.242834 )
Norm@50keV  : 5.40075E-03    ( -0.00101626   0.00100086 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          72.94 using 59 PHA bins.
# Reduced chi-squared =          1.280 for     57 degrees of freedom 
# Null hypothesis probability =   7.578158e-02
 
Photon flux (15-150 keV)    in 1 sec: 0.739048 ( -0.118232  0.118234 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.97416e-08 ( -9.41422e-09  9.69035e-09 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.040 sec. to    0.960 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.22595     ( -1.51439   2.0787 )
Epeak [keV] : 43.8335      ( -6.17183 8.80326 )
Norm@50keV  : 0.299385    ( -0.314834   4.80722 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.92 using 59 PHA bins.
# Reduced chi-squared =          1.034 for     56 degrees of freedom 
# Null hypothesis probability =   4.042251e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.705278 ( -0.114936  0.11599 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.15901e-08 ( -7.77272e-09  8.7391e-09 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 51.524 sec.
Hardness ratio (energy fluence ratio) = 0.911191973166

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

S(15-50 keV)  = 1.7194084e-07
S(50-150 keV) = 1.3440102e-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 = 8.149817189806598E-03, IMY = 1.716909899493872E-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:
-239.192000 -0.952000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
185.0483  -8.2768    3.6  55.7   11.0   3.3969   3.3 ------	UNKNOWN                       
 73.6947  55.5627    2.7  54.2  177.7   2.7114   4.2 ------	UNKNOWN                       
216.6938  22.9125    4.6  50.7  -44.4   2.3094   2.5 ------	UNKNOWN                       

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

Time interval of the image:
-0.952000 18.508600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
155.1234  13.9292    2.6  28.8   51.1   0.2601   4.5 ------	UNKNOWN                       
104.5524  43.4678    2.4  39.6  152.7   0.3765   4.9 ------	UNKNOWN                       
155.6504  49.1195    2.7   7.2 -159.9   0.1672   4.3 ------	UNKNOWN                       
171.0926  48.0756    1.2   9.8  -87.3   0.3914   9.8 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
47.908600 839.499400
840.808000 962.855400
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 70.2698  65.6083    2.5  51.3 -178.1   5.7645   4.6 ------	UNKNOWN                       
182.6281  39.4763    2.6  11.9  -15.1   1.8662   4.5 ------	UNKNOWN                       
225.2557  21.1789    5.1  50.7  -44.5   6.5008   2.4 ------	UNKNOWN                       
224.8690  18.9567    3.0  52.0  -42.2  10.2280   3.8 ------	UNKNOWN                       
225.4821  21.0833    4.5  50.9  -44.6   8.6974   3.0 ------	UNKNOWN