GRB150120B: 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 Feb 11 07:45:39 EST 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger627170
======================================================================

  Trigger: 00627170      Segment: 000

  BAT Trigger Time: 443431328.704   [s; MET]
      Trigger Stop: 443431330.752   [s; MET]
               UTC: 2015-01-20T07:21:55.628600    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 39.2941689420528   Dec: 8.07853027689263  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.1
     Image Trigger?:     NO
     Rate S/N Ratio:     7.74596669241483  [ if not an image trigger ]
     Image S/N Ratio:    7.1

  Analysis Position:   [ source = BAT ]
    RA: 39.2941689420528   Dec: 8.07853027689263  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 39.307209627024   Dec: 8.06433552121301  [deg; J2000]  
        { 02h 37m 13.7s , +08d 03' 51.6" }
         +/- 2.29447489656789 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.15458113426643 [arcmin] (formal 1-sigma fit error)
    SNR: 9.28659504231606
 
  Angular difference between the analysis and refined position is 1.151309 arcmin
 
  Partial Coding Fraction: 0.3554688    [ including projection effects ]

  Duration
     T90: 24.3359999656677 +/- 3.27792376660314
        Measured from: -15.7319999933243
                   to: 8.60399997234344     [s; relative to TRIGTIME]
     T50: 14.0119999647141 +/- 6.95071221860736
        Measured from: -10.9480000138283
                   to: 3.06399995088577     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.583999991416931     
                   to: 1.58399999141693     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -17.6359999775887     
                   to: 10.5440000295639     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.396165   0.392244   0.190429   0.022831
           0.045335   0.046000   0.039353   0.033665 [error]
 Peak      0.048064   0.044288   0.034724   0.009731
           0.009213   0.009460   0.007741   0.006082 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   28.180  -17.636   10.544
T90    24.336  -15.732    8.604
T50    14.012  -10.948    3.064
Peak    1.000    0.584    1.584
 
 
====== 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      -2.236    -0.271      0.247       -           -               -         2.00e-03     -3.76e-04          3.66e-04      46.930   57
CPL     -2.221     N/A        N/A        10000.000      N/A           N/A         2.03e-03        N/A               N/A         46.950   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      -1.938     -0.381     0.341       -           -               -         8.37e-03     -2.01e-03          1.91e-03      60.280   57
CPL     -1.683     -0.518     1.981       57.099      N/A           N/A         1.16e-02        N/A               N/A         60.210   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   1.45e-07  1.70e-07  1.45e-07  2.08e-07  5.34e-07  6.68e-07   erg/cm2
      90%_error_low -2.44e-08 -2.32e-08 -3.58e-08 -8.51e-08 -8.35e-08 -1.36e-07   erg/cm2
      90%_error_hi   2.49e-08  2.30e-08  3.74e-08  1.17e-07  8.59e-08  1.59e-07   erg/cm2
Peak flux       PL   5.25e-01  4.08e-01  2.13e-01  1.61e-01  1.22e+00  1.31e+00   ph/cm2/s
      90%_error_low -1.47e-01 -7.99e-02 -6.54e-02 -7.90e-02 -2.41e-01 -2.56e-01   ph/cm2/s
      90%_error_hi   1.56e-01  7.98e-02  6.48e-02  1.10e-01  2.41e-01  2.57e-01   ph/cm2/s
 
Fluence        CPL   1.39e-07  1.85e-07  1.36e-07  6.29e-08  5.01e-07  5.22e-07   erg/cm2
      90%_error_low -2.70e-08    N/A    -4.67e-08    N/A    -8.94e-08 -1.09e-07   erg/cm2
      90%_error_hi   2.62e-08    N/A     4.26e-08    N/A     9.80e-08  1.32e-07   erg/cm2
Peak flux      CPL   5.09e-01  4.21e-01  2.17e-01  1.17e-01  1.21e+00  1.26e+00   ph/cm2/s
      90%_error_low     N/A   -1.05e-01     N/A   -1.17e-01 -2.48e-01 -2.88e-01   ph/cm2/s
      90%_error_hi      N/A    1.17e-01     N/A    1.26e-01  2.46e-01  2.91e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   39.3072     8.0643   0.0208    37.2135   146.5094         0.9767557      9.287 TRIG_00627170                 
 
Foreground time interval of the image:
-17.636  10.544 (delta_t =  28.180 [sec])
Background time interval of the image:
-63.603 -17.636 (delta_t =  45.967 [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  -17.636 sec. to   10.544 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.23627     ( -0.270794   0.24687 )
Norm@50keV  : 2.00490E-03    ( -0.000376279   0.000366019 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.93 using 59 PHA bins.
# Reduced chi-squared =         0.8232 for     57 degrees of freedom 
# Null hypothesis probability =   8.269769e-01
 
Photon flux (15-150 keV)    in 28.18 sec: 0.338414 ( -0.043661  0.043663 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.34183e-07 ( -8.35416e-08  8.59445e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -17.636 sec. to   10.544 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.22079     (       )
Epeak [keV] : 1.00000E+04      (   )
Norm@50keV  : 2.03242E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          46.95 using 59 PHA bins.
# Reduced chi-squared =         0.8383 for     56 degrees of freedom 
# Null hypothesis probability =   8.002571e-01
 
Photon flux (15-150 keV)    in 28.18 sec: 0.331431 ( -0.044718  0.044804 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.00694e-07 ( -8.93822e-08  9.79948e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.584 sec. to    1.584 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.93752     ( -0.381415   0.341447 )
Norm@50keV  : 8.36696E-03    ( -0.00200835   0.00191167 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.28 using 59 PHA bins.
# Reduced chi-squared =          1.058 for     57 degrees of freedom 
# Null hypothesis probability =   3.580096e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.22041 ( -0.240593  0.24082 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.69857e-08 ( -1.7392e-08  1.76881e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.584 sec. to    1.584 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.68255     ( -0.517112   1.98158 )
Epeak [keV] : 57.0992      (   )
Norm@50keV  : 1.15523E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.21 using 59 PHA bins.
# Reduced chi-squared =          1.075 for     56 degrees of freedom 
# Null hypothesis probability =   3.260391e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.21203 ( -0.248231  0.2456 ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 24.336 sec.
Hardness ratio (energy fluence ratio) = 0.848985324773

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

S(15-50 keV)  = 3.151945e-07
S(50-150 keV) = 2.1899088e-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 = -6.333327799551866E-01, IMY = -4.190438209869349E-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:
-63.603400 -17.636000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.2660  40.9006   10.5  48.7  -43.7  -0.2463  -1.1    7.7	Cyg X-3                       
326.1872  38.1970    6.0  35.6  -51.2   0.1852   1.9    7.5	Cyg X-2                       
 40.4090  62.6001    2.5  34.2   43.2   0.4799   4.6 ------	UNKNOWN                       
 27.0051  -3.5422    2.6  40.7  173.0   0.4505   4.4 ------	UNKNOWN                       
 23.6430 -22.8729    2.7  58.3 -175.4   1.6455   4.3 ------	UNKNOWN                       

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

Time interval of the image:
-17.636000 10.544000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.1059  40.9036    5.3  48.8  -43.6   0.4538   2.2    2.9	Cyg X-3                       
326.3884  38.3210    6.6  35.4  -51.0  -0.1517  -1.8   10.2	Cyg X-2                       
 58.2308  35.0339    1.9  39.1   93.5   1.4603   6.0 ------	UNKNOWN                       
 39.3072   8.0643    1.2  37.2  146.5   0.9765   9.3 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
411.896610 962.324800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 21.0265  40.6988    2.6  36.4   -4.2   1.7602   4.4 ------	UNKNOWN                       
 26.2867  31.2668    3.5  26.2   -6.4   0.9661   3.3 ------	UNKNOWN                       
 57.8779 -47.8163    2.8  58.3 -175.2   7.4336   4.1 ------	UNKNOWN                       
  6.6485 -20.8370    2.2  43.2 -113.2   7.2336   5.2 ------	UNKNOWN