GRB150720A

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: Fri Aug  7 22:43:33 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger649706
======================================================================

  Trigger: 00649706      Segment: 000

  BAT Trigger Time: 459093744   [s; MET]
      Trigger Stop: 459093808   [s; MET]
               UTC: 2015-07-20T14:02:09.120700    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 119.582501208641   Dec: -28.3009627793679  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.55
     Image Trigger?:     YES
     Rate S/N Ratio:     0  [ if not an image trigger ]
     Image S/N Ratio:    7.55

  Analysis Position:   [ source = BAT ]
    RA: 119.582501208641   Dec: -28.3009627793679  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 119.583   Dec: -28.301  [deg; J2000]
        { 07h 58m 19.9s , -28d -18' -3.6" }
        +/- 2.14183486279 [arcmin] (estimated 90% radius based on SNR)
    SNR: 10.2476384118
 
 
  Angular difference between the analysis and refined position is 0.026445 arcmin
 
  Partial Coding Fraction: 1.015625    [ including projection effects ]

  Duration
     T90: 238.535999953747 +/- 44.4195098491896
        Measured from: -122.34399998188
                   to: 116.191999971867     [s; relative to TRIGTIME]
     T50: 138.075999975204 +/- 56.825518919244
        Measured from: -91.160000026226
                   to: 46.9159999489784     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -182.276000022888     
                   to: -181.276000022888     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -182.639999985695     
                   to: 122.867999970913     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.899414   0.563440   0.207311   0.096377
           0.101130   0.103665   0.088545   0.074619 [error]
 Peak      0.045225   0.024130   0.009531   0.012343
           0.018471   0.018702   0.015488   0.012972 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  305.508 -182.640  122.868
T90   238.536 -122.344  116.192
T50   138.076  -91.160   46.916
Peak    1.000 -182.276 -181.276
 
 
====== 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      -2.478    -0.419      0.359       -           -               -         2.55e-04     -7.67e-05          7.64e-05      50.310   57
CPL     -1.983    -0.016      1.656        1.205      -0.658        25.957      5.30e-04     -4.51e-04          -2.06e-04      50.930   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      -3.592     -2.331     1.165       -           -               -         2.56e-03     -2.56e-03          3.92e-03      59.690   57
CPL     -1.893      N/A       N/A           1.781      N/A           N/A         4.22e-02        N/A               N/A         59.540   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   2.51e-07  2.56e-07  1.84e-07  2.11e-07  7.75e-07  9.03e-07   erg/cm2
      90%_error_low -4.87e-08 -5.23e-08 -7.05e-08 -1.21e-07 -1.67e-07 -2.39e-07   erg/cm2
      90%_error_hi   4.88e-08  4.96e-08  8.05e-08  2.06e-07  1.79e-07  3.07e-07   erg/cm2
Peak flux       PL   8.22e-01  2.49e-01  4.14e-02  7.93e-03  1.12e+00  1.12e+00   ph/cm2/s
      90%_error_low -4.49e-01 -1.92e-01 -4.14e-02 -7.93e-03 -5.83e-01 -5.85e-01   ph/cm2/s
      90%_error_hi   4.58e-01  1.97e-01  9.28e-02  5.27e-02  5.88e-01  5.90e-01   ph/cm2/s
 
Fluence        CPL   2.47e-07  2.31e-07  1.57e-07  2.03e-07  7.06e-07  8.37e-07   erg/cm2
      90%_error_low -5.29e-08 -9.84e-08 -1.03e-07 -1.68e-07 -2.85e-07 -3.94e-07   erg/cm2
      90%_error_hi   5.18e-08  7.34e-08  1.08e-07  2.90e-07  2.53e-07  4.44e-07   erg/cm2
Peak flux      CPL     N/A      N/A      N/A      N/A      N/A      N/A     ph/cm2/s
      90%_error_low -4.49e-01 -1.92e-01 -4.14e-02 -7.93e-03 -5.83e-01 -5.85e-01   ph/cm2/s
      90%_error_hi   4.58e-01  1.97e-01  9.28e-02  5.27e-02  5.88e-01  5.90e-01   ph/cm2/s
 
======================================================================

Special notes of this burst

Image

Pre-slew 15.0-50.0 keV image (Event data)

#RAcent DECcent POSerr Theta  Phi  Peak_Cts  SNR Name
119.583 -28.301 0.000 16.960 -168.686 0.574 10.248 TRIG_00649706
 
Image time interval: 0.000 to 64.000 [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 -182.640 sec. to  122.868 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.47811     ( -0.419331   0.359337 )
Norm@50keV  : 2.54963E-04    ( -7.67376e-05   7.63848e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.31 using 59 PHA bins.
# Reduced chi-squared =         0.8827 for     57 degrees of freedom 
# Null hypothesis probability =   7.222544e-01
 
Photon flux (15-150 keV)    in 305.5 sec: 4.94304E-02 ( -0.0079925  0.0080005 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.74571e-07 ( -1.67302e-07  1.79282e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from -182.640 sec. to  122.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.70295     ( -0.0158011   1.65579 )
Epeak [keV] : 251.336      ( -0.657675 25.9574 )
Norm@50keV  : 1.91432E-04    ( -0.000112798   0.000132288 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.12 using 59 PHA bins.
# Reduced chi-squared =         0.8950 for     56 degrees of freedom 
# Null hypothesis probability =   6.959463e-01
 
Photon flux (15-150 keV)    in 305.5 sec: 4.94774E-02 ( -0.008173  0.0077417 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.06206e-07 ( -2.85061e-07  2.52601e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from -182.276 sec. to -181.276 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -3.59155     ( -2.33476   1.16102 )
Norm@50keV  : 2.56147E-03    ( -0.00256651   0.00391279 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.69 using 59 PHA bins.
# Reduced chi-squared =          1.047 for     57 degrees of freedom 
# Null hypothesis probability =   3.781747e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.11701 ( -0.583377  0.58782 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.27199e-08 ( -2.46261e-08  2.85818e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from -182.276 sec. to -181.276 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.89348     (       )
Epeak [keV] : 1.78097      (   )
Norm@50keV  : 4.22357E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.54 using 59 PHA bins.
# Reduced chi-squared =          1.063 for     56 degrees of freedom 
# Null hypothesis probability =   3.482397e-01
 
Photon flux (15-150 keV)    in 1 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 238.536 sec.
Hardness ratio (energy fluence ratio) = 0.717959547554

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

S(15-50 keV)  = 5.079157e-07
S(50-150 keV) = 2.6666299e-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 = -0.29903606316, IMY = 0.0598278270123

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:

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

Time interval of the image:
-82.099400 72.700610
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.3964 -40.6670    7.9  17.7  128.4   0.2104   1.5    9.0	Vela X-1                      
 91.3761 -57.4191    2.4  47.7  154.9   2.0362   4.8 ------	UNKNOWN                       
119.6001 -28.2940    1.7  16.9 -168.7   0.8950   6.8 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
122.900600 963.107000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5559 -40.5237   63.8  17.9   47.3  -0.0817  -0.2    2.2	Vela X-1                      
 73.8149 -25.5760    3.1  40.7  173.0   2.7841   3.8 ------	UNKNOWN                       
156.5810 -20.3823    2.5  34.5   -4.8   2.7468   4.6 ------	UNKNOWN                       
169.9974 -11.2112    2.9  50.0   -9.3   3.8100   4.0 ------	UNKNOWN                       
 64.6146  -3.9698    2.9  57.5 -165.4   9.9175   4.0 ------	UNKNOWN                       
116.1475   2.2290    2.8  30.7  -96.6   3.0004   4.1 ------	UNKNOWN                       
117.1374  12.4855    3.5  40.9  -93.5   8.3983   3.3 ------	UNKNOWN

Analysis Summary

Notes:

Image

Pre-slew 15.0-50.0 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