GRB160220B

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: Thu Mar 17 18:24:23 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger674734
======================================================================

  Trigger: 00674734      Segment: 000

  BAT Trigger Time: 477659469.696   [s; MET]
      Trigger Stop: 477659470.72   [s; MET]
               UTC: 2016-02-20T11:10:53.826540    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 259.854260978407   Dec: -18.1230465541461  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.83
     Image Trigger?:     NO
     Rate S/N Ratio:     20.8086520466848  [ if not an image trigger ]
     Image S/N Ratio:    10.83

  Analysis Position:   [ source = BAT ]
    RA: 259.854260978407   Dec: -18.1230465541461  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 259.851012840328   Dec: -18.1236946040632  [deg; J2000]  
        { 17h 19m 24.2s , -18d 07' 25.3" }
         +/- 0.688840270580772 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.212199186327149 [arcmin] (formal 1-sigma fit error)
    SNR: 51.8057093617244
 
  Angular difference between the analysis and refined position is 0.189257 arcmin
 
  Partial Coding Fraction: 0.3867188    [ including projection effects ]

  Duration
     T90: 31.1159999370575 +/- 3.01692293709113
        Measured from: -3.62799996137619
                   to: 27.4879999756813     [s; relative to TRIGTIME]
     T50: 8.2399999499321 +/- 0.554400592062718
        Measured from: 4.80800002813339
                   to: 13.0479999780655     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 6.46000003814697     
                   to: 7.46000003814697     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -7.57599997520447     
                   to: 37.4840000271797     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.768582   3.389573   3.475739   1.114980
           0.078213   0.083086   0.074934   0.057145 [error]
 Peak      0.127068   0.278745   0.317604   0.111362
           0.013595   0.016535   0.016728   0.012705 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   45.060   -7.576   37.484
T90    31.116   -3.628   27.488
T50     8.240    4.808   13.048
Peak    1.000    6.460    7.460
 
 
====== 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      -1.192    -0.046      0.047       -           -               -         1.54e-02     -4.19e-04          4.18e-04      56.740   57
CPL     -0.735    -0.194      0.203      166.842     -32.966        75.238      2.40e-02     -4.02e-03          5.02e-03      39.560   56
 
 
=== 1-s peak 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      -0.985     -0.097     0.099       -           -               -         5.73e-02     -3.50e-03          3.50e-03      64.180   57
CPL     -0.112     -0.446     0.497      127.933     -26.282        70.107      1.37e-01     -4.83e-02          8.34e-02      52.030   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   6.65e-07  1.48e-06  2.58e-06  1.06e-05  7.06e-06  1.53e-05   erg/cm2
      90%_error_low -3.73e-08 -5.02e-08 -7.33e-08 -6.70e-07 -1.91e-07 -7.00e-07   erg/cm2
      90%_error_hi   3.81e-08  5.01e-08  7.31e-08  7.00e-07  1.91e-07  7.25e-07   erg/cm2
Peak flux       PL   1.44e+00  1.98e+00  2.00e+00  3.66e+00  6.60e+00  9.08e+00   ph/cm2/s
      90%_error_low -1.71e-01 -1.50e-01 -1.27e-01 -4.60e-01 -4.10e-01 -5.82e-01   ph/cm2/s
      90%_error_hi   1.79e-01  1.49e-01  1.26e-01  4.98e-01  4.10e-01  5.89e-01   ph/cm2/s
 
Fluence        CPL   5.83e-07  1.50e-06  2.72e-06  6.39e-06  6.96e-06  1.12e-05   erg/cm2
      90%_error_low -4.81e-08 -5.37e-08 -9.31e-08 -1.13e-06 -1.98e-07 -1.13e-06   erg/cm2
      90%_error_hi   4.93e-08  5.38e-08  9.38e-08  1.44e-06  1.97e-07  1.42e-06   erg/cm2
Peak flux      CPL   1.14e+00  2.06e+00  2.23e+00  1.83e+00  6.44e+00  7.26e+00   ph/cm2/s
      90%_error_low -2.13e-01 -1.69e-01 -1.72e-01 -4.95e-01 -4.17e-01 -6.53e-01   ph/cm2/s
      90%_error_hi   2.25e-01  1.69e-01  1.75e-01  7.22e-01  4.18e-01  8.02e-01   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
  259.8510   -18.1237   0.0037    40.7650    10.9593        10.2785765     51.806 TRIG_00674734                 
 
Foreground time interval of the image:
 -7.576  37.484 (delta_t =  45.060 [sec])
Background time interval of the image:
-518.195 -407.172 (delta_t = 111.023 [sec])
-239.696  -7.576 (delta_t = 232.120 [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   -7.576 sec. to   37.484 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.19177     ( -0.0464309   0.0467533 )
Norm@50keV  : 1.54061E-02    ( -0.000418707   0.000418013 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.74 using 59 PHA bins.
# Reduced chi-squared =         0.9954 for     57 degrees of freedom 
# Null hypothesis probability =   4.848752e-01
 
Photon flux (15-150 keV)    in 45.06 sec: 1.80631 ( -0.05313  0.05326 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.06027e-06 ( -1.90517e-07  1.90617e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -7.576 sec. to   37.484 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.734944     ( -0.193596   0.202535 )
Epeak [keV] : 166.842      ( -32.9657 75.2378 )
Norm@50keV  : 2.40196E-02    ( -0.00401571   0.00502484 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          39.56 using 59 PHA bins.
# Reduced chi-squared =         0.7065 for     56 degrees of freedom 
# Null hypothesis probability =   9.528441e-01
 
Photon flux (15-150 keV)    in 45.06 sec: 1.76106 ( -0.05586  0.05605 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.95524e-06 ( -1.97812e-07  1.97318e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    6.460 sec. to    7.460 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.98472     ( -0.0972645   0.0987314 )
Norm@50keV  : 5.73360E-02    ( -0.00350428   0.0034957 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.18 using 59 PHA bins.
# Reduced chi-squared =          1.126 for     57 degrees of freedom 
# Null hypothesis probability =   2.393922e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.59605 ( -0.40964  0.41022 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.23462e-07 ( -3.96003e-08  3.96853e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    6.460 sec. to    7.460 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.111769     ( -0.446324   0.497343 )
Epeak [keV] : 127.933      ( -26.2817 70.1071 )
Norm@50keV  : 0.137341    ( -0.0483403   0.0833729 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.03 using 59 PHA bins.
# Reduced chi-squared =         0.9291 for     56 degrees of freedom 
# Null hypothesis probability =   6.258415e-01
 
Photon flux (15-150 keV)    in 1 sec: 6.43579 ( -0.41737  0.41785 ) ph/cm2/s
Energy fluence (15-150 keV)             : 6.09425e-07 ( -4.15536e-08  4.14087e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 31.116 sec.
Hardness ratio (energy fluence ratio) = 1.81150721737

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

S(15-50 keV)  = 2.086494e-06
S(50-150 keV) = 4.868672e-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 = 8.463877121934957E-01, IMY = -1.638978551286601E-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:
-518.195400 -407.172500
-239.696000 -7.576000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3567  35.2453   10.6  39.5   99.7  -1.3259  -1.1    7.6	Her X-1                       
256.4363 -36.4229   16.4  56.3   -2.7   1.2116   0.7    0.0	GX 349+2                      
262.8983 -24.7109  242.0  43.7    1.2   0.0283   0.0    6.4	GX 1+4                        
268.3258  -1.2461    0.0  23.7   26.5   0.2170   0.6   12.6	SW J1753.5-0127               
270.2846 -25.0745   96.1  40.3   -7.4  -0.0587  -0.1    0.3	GX 5-1                        
270.3027 -25.7430   14.5  40.9   -7.9   0.3794   0.8    0.0	GRS 1758-258                  
273.9137 -13.9518    3.8  29.0   -2.8   1.0348   3.0    7.4	GX 17+2                       
275.9152 -30.3033   37.1  43.1  -17.5  -0.1586  -0.3    3.9	H1820-303                     
285.0218 -25.0788    7.3  36.2  -28.0  -0.6563  -1.6    9.5	HT1900.1-2455                 
288.7363  10.9469    1.6   0.1   35.8   2.0434   7.1    3.7	GRS 1915+105                  
299.5890  35.2051    0.2  26.2  166.5  15.1972  46.6    0.2	Cyg X-1                       
308.1076  40.9559    1.9  34.5  172.4   2.5796   6.1    0.2	Cyg X-3                       
326.1187  38.1291    0.0  43.0 -169.4  -0.1818  -0.4   11.8	Cyg X-2                       
263.1347 -33.8129    6.1  51.0   -6.2  -1.6004  -1.9    7.4	GX 354-0                      
260.6924 -35.1517    2.5  53.2   -5.1   4.4066   4.6 ------	UNKNOWN                       
335.5571  22.6490    3.4  46.1 -144.8   2.0041   3.4 ------	UNKNOWN                       
345.5946  23.7078    2.5  55.3 -145.1   9.2857   4.7 ------	UNKNOWN

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

Time interval of the image:
-7.576000 37.484000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3399  35.3467   53.9  39.6   99.8   0.0954   0.2    5.8	Her X-1                       
256.4317 -36.4197  396.9  56.3   -2.6  -0.0195  -0.0    0.3	GX 349+2                      
263.1290 -24.7810    5.0  43.6    0.9   0.4921   2.3    6.9	GX 1+4                        
268.3489  -1.4223   20.5  23.8   26.1  -0.0706  -0.6    2.1	SW J1753.5-0127               
270.2278 -25.1325   10.4  40.4   -7.4  -0.1884  -1.1    4.4	GX 5-1                        
270.3809 -25.6104  170.6  40.7   -7.9   0.0118   0.1    9.0	GRS 1758-258                  
273.9812 -13.8399    0.0  28.8   -2.8  -0.3173  -2.5   11.9	GX 17+2                       
275.8274 -30.4051    6.4  43.2  -17.4   0.2960   1.8    5.5	H1820-303                     
285.0648 -24.9546    9.5  36.1  -28.1   0.1695   1.2    2.6	HT1900.1-2455                 
289.0103  10.9866    0.0   0.2 -129.4   0.1389   1.4   12.7	GRS 1915+105                  
299.5727  35.1869  173.5  26.1  166.5  -0.0083  -0.1    1.2	Cyg X-1                       
307.8716  40.9455    5.4  34.4  172.1   0.2923   2.1   10.8	Cyg X-3                       
326.2741  38.2449    5.2  43.2 -169.5  -0.3473  -2.2    6.7	Cyg X-2                       
263.1286 -33.7659    4.7  51.0   -6.2   0.6717   2.5    8.1	GX 354-0                      
259.8510 -18.1237    0.2  40.8   11.0  10.2782  51.8 ------	UNKNOWN                       
293.3451 -18.3826    2.2  29.7  -42.6   0.6245   5.4 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
241.604600 357.686000
360.304000 412.204590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
308.1762  40.9885    5.7  58.1  -15.9   1.5608   2.1    3.7	Cyg X-3                       
326.2846  38.3955    3.3  44.0  -16.6   0.8342   3.5    6.9	Cyg X-2                       
 56.7383   1.7196    2.1  47.3  142.2   4.0409   5.4 ------	UNKNOWN                       
309.1987  36.3895    2.2  57.2  -21.3   3.2896   5.2 ------	UNKNOWN                       
335.4808  12.9904    2.6  35.1  -56.9   0.9940   4.5 ------	UNKNOWN                       
 13.3043 -36.8263    3.5  55.3 -144.9   3.0575   3.3 ------	UNKNOWN                       
316.2640  19.7284    2.9  52.1  -42.2   3.2003   4.0 ------	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