GRB141220A: 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  4 09:32:41 EST 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger621915
======================================================================

  Trigger: 00621915      Segment: 000

  BAT Trigger Time: 440748185.6   [s; MET]
      Trigger Stop: 440748186.624   [s; MET]
               UTC: 2014-12-20T06:02:52.659420    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 195.049884054191   Dec: 32.1436131040692  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    15.59
     Image Trigger?:     NO
     Rate S/N Ratio:     48.2078831727758  [ if not an image trigger ]
     Image S/N Ratio:    15.59

  Analysis Position:   [ source = BAT ]
    RA: 195.049884054191   Dec: 32.1436131040692  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 195.05764349687   Dec: 32.1470666399717  [deg; J2000]  
        { 13h 00m 13.8s , +32d 08' 49.4" }
         +/- 1.12645970885531 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.359279991173662 [arcmin] (formal 1-sigma fit error)
    SNR: 25.6589489150577
 
  Angular difference between the analysis and refined position is 0.445339 arcmin
 
  Partial Coding Fraction: 0.1972656    [ including projection effects ]

  Duration
     T90: 7.23199993371964 +/- 0.479015658049012
        Measured from: -0.424000024795532
                   to: 6.8079999089241     [s; relative to TRIGTIME]
     T50: 3.06399995088577 +/- 1.30083050676259
        Measured from: 0.35999995470047
                   to: 3.42399990558624     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -0.128000020980835     
                   to: 0.871999979019165     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.90800005197525     
                   to: 7.2960000038147     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.657405   1.199131   1.274516   0.412260
           0.052709   0.059743   0.055899   0.041703 [error]
 Peak      0.144199   0.350898   0.451093   0.177381
           0.020739   0.026769   0.027535   0.019597 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    8.204   -0.908    7.296
T90     7.232   -0.424    6.808
T50     3.064    0.360    3.424
Peak    1.000   -0.128    0.872
 
 
====== 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: CPL)
 
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      -1.304    -0.083      0.083       -           -               -         3.22e-02     -1.63e-03          1.63e-03      64.410   57
CPL     -0.615    -0.366      0.399      116.098     -22.886        64.670      6.53e-02     -2.00e-02          3.15e-02      53.420   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      -1.050     -0.119     0.121       -           -               -         7.74e-02     -5.98e-03          5.96e-03      81.370   57
CPL     -0.249     -0.536     0.611      128.642     -32.163       133.958      1.75e-01     -7.21e-02          1.41e-01      74.560   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   2.80e-07  5.81e-07  9.42e-07  3.43e-06  2.61e-06  5.23e-06   erg/cm2
      90%_error_low -2.70e-08 -3.51e-08 -5.27e-08 -3.99e-07 -1.35e-07 -4.31e-07   erg/cm2
      90%_error_hi   2.79e-08  3.49e-08  5.25e-08  4.31e-07  1.36e-07  4.56e-07   erg/cm2
Peak flux       PL   4.14e-04  5.08e-03  5.68e-02  5.44e+00  2.55e-01  5.45e+00   ph/cm2/s
      90%_error_low -1.68e-06 2.72e-05 1.04e-03 -4.17e-01 6.64e-03 -3.61e-01   ph/cm2/s
      90%_error_hi   2.06e-04  2.32e-03  2.38e-02  1.07e+00  1.03e-01  1.18e+00   ph/cm2/s
 
Fluence        CPL   2.36e-07  6.09e-07  1.02e-06  1.64e-06  2.56e-06  3.51e-06   erg/cm2
      90%_error_low -3.39e-08 -3.95e-08 -6.72e-08 -4.77e-07 -1.41e-07 -4.82e-07   erg/cm2
      90%_error_hi   3.50e-08  4.00e-08  6.82e-08  7.30e-07  1.40e-07  7.18e-07   erg/cm2
Peak flux      CPL   1.68e+00  2.86e+00  2.95e+00  2.40e+00  8.79e+00  9.89e+00   ph/cm2/s
      90%_error_low -3.75e-01 -2.95e-01 -2.87e-01 -7.77e-01 -7.19e-01 -1.07e+00   ph/cm2/s
      90%_error_hi   3.98e-01  2.98e-01  2.91e-01  1.23e+00  7.20e-01  1.35e+00   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  195.0576    32.1471   0.0075    50.8232  -153.9835         3.7137945     25.659 TRIG_00621915                 
 
Foreground time interval of the image:
 -0.908   7.296 (delta_t =   8.204 [sec])
Background time interval of the image:
-294.499 -276.524 (delta_t =  17.976 [sec])
-239.600  -0.908 (delta_t = 238.692 [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   -0.908 sec. to    7.296 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.30359     ( -0.0826502   0.0832992 )
Norm@50keV  : 3.21766E-02    ( -0.00163143   0.0016301 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.41 using 59 PHA bins.
# Reduced chi-squared =          1.130 for     57 degrees of freedom 
# Null hypothesis probability =   2.333203e-01
 
Photon flux (15-150 keV)    in 8.204 sec: 3.84135 ( -0.2105  0.21109 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.60661e-06 ( -1.3542e-07  1.3557e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.908 sec. to    7.296 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.614702     ( -0.366232   0.399137 )
Epeak [keV] : 116.098      ( -22.8862 64.6692 )
Norm@50keV  : 6.52679E-02    ( -0.0200062   0.0315426 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.42 using 59 PHA bins.
# Reduced chi-squared =         0.9539 for     56 degrees of freedom 
# Null hypothesis probability =   5.731293e-01
 
Photon flux (15-150 keV)    in 8.204 sec: 3.73346 ( -0.21708  0.21809 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.55803e-06 ( -1.40536e-07  1.40053e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   -0.128 sec. to    0.872 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.04984     ( -0.118756   0.121411 )
Norm@50keV  : 7.74170E-02    ( -0.00598253   0.00595978 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          81.37 using 59 PHA bins.
# Reduced chi-squared =          1.428 for     57 degrees of freedom 
# Null hypothesis probability =   1.873043e-02
 
Photon flux (15-150 keV)    in 1 sec: 0.255427 0.280324 0.215982 0.166025 0.130088 0.104953 8.76381E-02 7.57277E-02 6.74503E-02 6.15910E-02 5.73478E-02 5.41999E-02 5.18087E-02 4.99517E-02 4.84804E-02 4.72935E-02 4.63204E-02 4.55113E-02 4.48299E-02 4.42496E-02 4.33211E-02 4.26091E-02 4.20480E-02 4.11903E-02 4.05493E-02 3.97186E-02 3.76361E-02 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.22925e-07 ( -6.41203e-08  6.42719e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -0.128 sec. to    0.872 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.249077     ( -0.536303   0.611475 )
Epeak [keV] : 128.642      ( -32.1639 133.957 )
Norm@50keV  : 0.174662    ( -0.0721079   0.14147 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          74.56 using 59 PHA bins.
# Reduced chi-squared =          1.331 for     56 degrees of freedom 
# Null hypothesis probability =   4.927705e-02
 
Photon flux (15-150 keV)    in 1 sec: 8.78846 ( -0.71857  0.72039 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.1169e-07 ( -6.67522e-08  6.63615e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 7.232 sec.
Hardness ratio (energy fluence ratio) = 1.67752894084

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

S(15-50 keV)  = 8.455602e-07
S(50-150 keV) = 1.7124699e-06

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 = -1.102785388212399E+00, IMY = 5.382570467303692E-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:
-294.499400 -276.523600
-239.600000 -0.908000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5382 -40.5620    2.3  50.9  -20.0   2.7199   5.0    0.6	Vela X-1                      
108.8093 -25.8019    2.7  50.3   14.7   3.0546   4.2 ------	UNKNOWN                       
124.1374 -20.4202    2.2  36.7    5.3   1.5345   5.3 ------	UNKNOWN                       
169.3360 -10.1920    3.4  30.6  -80.6   1.1484   3.4 ------	UNKNOWN                       
191.5253   7.6654    4.0  45.3 -121.4   2.9179   2.9 ------	UNKNOWN                       

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

Time interval of the image:
-0.908000 7.296000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.3254 -40.5700   17.6  51.0  -19.8   0.0545   0.7    9.3	Vela X-1                      
104.5958  -6.1092    2.8  43.8   40.8   0.4976   4.1 ------	UNKNOWN                       
135.1082  20.5697    2.2  15.1  108.6   0.2126   5.2 ------	UNKNOWN                       
185.1613  37.9185    2.4  45.4 -165.2   0.3760   4.9 ------	UNKNOWN                       
132.3770 -41.4883    2.6  52.4  -17.3   0.3941   4.4 ------	UNKNOWN                       
155.3725 -16.5119    2.6  27.7  -50.2   0.2248   4.5 ------	UNKNOWN                       
195.0576  32.1471    0.4  50.8 -154.0   3.7139  25.7 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
85.300600 962.477700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3559  35.1513    8.3  48.7 -139.1  -3.0202  -1.4   12.5	Her X-1                       
172.1180  45.7145    2.9  22.3  105.8   2.5300   3.9 ------	UNKNOWN                       
237.2297  52.7838    2.8  36.6 -165.4   2.8671   4.0 ------	UNKNOWN                       
227.6962  20.9927    2.8  31.1 -105.5   3.2106   4.1 ------	UNKNOWN                       
199.0103 -22.2040    2.7  54.5  -32.9  13.9709   4.3 ------	UNKNOWN                       
258.4869  34.2607    2.7  52.2 -139.1  12.5313   4.3 ------	UNKNOWN                       
250.9888  28.2425    3.7  48.0 -129.1   9.5401   3.1 ------	UNKNOWN                       
217.0670  -7.4954    6.3  44.9  -60.2   5.6241   1.8 ------	UNKNOWN