GRB160325A: 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: Thu Apr 14 18:20:30 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger680436
======================================================================

  Trigger: 00680436      Segment: 000

  BAT Trigger Time: 480582019.648   [s; MET]
      Trigger Stop: 480582020.16   [s; MET]
               UTC: 2016-03-25T07:00:03.619340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 15.5965562068455   Dec: -72.7063681344509  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.49
     Image Trigger?:     NO
     Rate S/N Ratio:     25.2784493195291  [ if not an image trigger ]
     Image S/N Ratio:    10.49

  Analysis Position:   [ source = BAT ]
    RA: 15.5965562068455   Dec: -72.7063681344509  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 15.6955921764478   Dec: -72.7017317557842  [deg; J2000]  
        { 01h 02m 46.9s , -72d 42' 06.2" }
         +/- 0.544890620605329 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.155575275615021 [arcmin] (formal 1-sigma fit error)
    SNR: 72.4134657961675
 
  Angular difference between the analysis and refined position is 1.788415 arcmin
 
  Partial Coding Fraction: 0.9609375    [ including projection effects ]

  Duration
     T90: 61.7239999771118 +/- 12.0532560498552
        Measured from: -40.9240000247955
                   to: 20.7999999523163     [s; relative to TRIGTIME]
     T50: 26.5359998941422 +/- 4.86102046732467
        Measured from: -35.5759999752045
                   to: -9.04000008106232     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: -33.4679999947548     
                   to: -32.4679999947548     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -51.7480000257492     
                   to: 59.3799999952316     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     2.414276   3.780245   3.385529   0.939801
           0.061473   0.065641   0.059625   0.051459 [error]
 Peak      0.134600   0.234638   0.227754   0.074036
           0.007672   0.009037   0.008956   0.006875 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  111.128  -51.748   59.380
T90    61.724  -40.924   20.800
T50    26.536  -35.576   -9.040
Peak    1.000  -33.468  -32.468
 
 
====== 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      -1.270    -0.042      0.042       -           -               -         6.42e-03     -1.40e-04          1.40e-04      37.260   57
CPL     -1.119    -0.073      0.170      340.686    -148.388      -340.686      7.46e-03     -8.44e-04          1.33e-03      34.810   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      -1.109     -0.075     0.075       -           -               -         4.52e-02     -1.89e-03          1.89e-03      44.020   57
CPL     -0.917     -0.224     0.293      316.808    -316.808      -316.808      5.53e-02     -1.16e-02          1.92e-02      42.610   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   7.35e-07  1.55e-06  2.58e-06  9.71e-06  7.10e-06  1.46e-05   erg/cm2
      90%_error_low -3.46e-08 -4.25e-08 -6.36e-08 -5.63e-07 -1.61e-07 -5.89e-07   erg/cm2
      90%_error_hi   3.53e-08  4.24e-08  6.35e-08  5.88e-07  1.61e-07  6.09e-07   erg/cm2
Peak flux       PL   1.28e+00  1.63e+00  1.51e+00  2.46e+00  5.25e+00  6.88e+00   ph/cm2/s
      90%_error_low -1.06e-01 -8.23e-02 -7.23e-02 -2.47e-01 -2.25e-01 -3.13e-01   ph/cm2/s
      90%_error_hi   1.09e-01  8.18e-02  7.20e-02  2.64e-01  2.25e-01  3.16e-01   ph/cm2/s
 
Fluence        CPL   7.04e-07  1.56e-06  2.62e-06  8.01e-06  7.04e-06  1.29e-05   erg/cm2
      90%_error_low -4.66e-08 -4.40e-08 -7.51e-08 -1.47e-06 -1.75e-07 -1.47e-06   erg/cm2
      90%_error_hi   4.76e-08  4.41e-08  7.56e-08  1.82e-06  1.74e-07  1.83e-06   erg/cm2
Peak flux      CPL   1.22e+00  1.65e+00  1.54e+00  2.00e+00  5.21e+00  6.41e+00   ph/cm2/s
      90%_error_low -1.34e-01 -8.74e-02 -8.61e-02 -5.04e-01 -2.33e-01 -5.61e-01   ph/cm2/s
      90%_error_hi   1.31e-01  8.82e-02  8.71e-02  5.40e-01  2.33e-01  6.25e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   15.6956   -72.7017   0.0026    19.9236     8.4173         8.1938033     72.413 TRIG_00680436                 
 
Foreground time interval of the image:
-37.547  10.253 (delta_t =  47.800 [sec])
Background time interval of the image:

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  -51.748 sec. to   59.380 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.27033     ( -0.0415707   0.0416918 )
Norm@50keV  : 6.42151E-03    ( -0.00014019   0.000140054 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          37.26 using 59 PHA bins.
# Reduced chi-squared =         0.6537 for     57 degrees of freedom 
# Null hypothesis probability =   9.800420e-01
 
Photon flux (15-150 keV)    in 111.1 sec: 0.762081 ( -0.018298  0.018347 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.1032e-06 ( -1.60729e-07  1.60937e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -51.748 sec. to   59.380 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.11926     ( -0.0734339   0.170199 )
Epeak [keV] : 340.686      ( -148.392 -340.689 )
Norm@50keV  : 7.45783E-03    ( -0.000844095   0.00132833 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          34.81 using 59 PHA bins.
# Reduced chi-squared =         0.6216 for     56 degrees of freedom 
# Null hypothesis probability =   9.882856e-01
 
Photon flux (15-150 keV)    in 111.1 sec: 0.753525 ( -0.020324  0.020436 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.04132e-06 ( -1.74839e-07  1.74143e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from  -33.468 sec. to  -32.468 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.10914     ( -0.0745419   0.0748868 )
Norm@50keV  : 4.52392E-02    ( -0.00188758   0.0018872 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.02 using 59 PHA bins.
# Reduced chi-squared =         0.7723 for     57 degrees of freedom 
# Null hypothesis probability =   8.959240e-01
 
Photon flux (15-150 keV)    in 1 sec: 5.25219 ( -0.22456  0.22473 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.71672e-07 ( -2.20578e-08  2.21268e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -33.468 sec. to  -32.468 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.917082     ( -0.223566   0.292646 )
Epeak [keV] : 316.808      ( -316.808 -316.808 )
Norm@50keV  : 5.53485E-02    ( -0.0115679   0.0191703 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          42.61 using 59 PHA bins.
# Reduced chi-squared =         0.7609 for     56 degrees of freedom 
# Null hypothesis probability =   9.063593e-01
 
Photon flux (15-150 keV)    in 1 sec: 5.20682 ( -0.23346  0.23346 ) ph/cm2/s
Energy fluence (15-150 keV)             : 4.66692e-07 ( -2.34203e-08  2.33011e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 61.724 sec.
Hardness ratio (energy fluence ratio) = 1.65828907173

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

S(15-50 keV)  = 2.2894759e-06
S(50-150 keV) = 4.813702e-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 = 3.585564300898409E-01, IMY = -5.305764088187091E-02

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:
-37.547400 10.252640
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
264.6237 -44.3193   11.3  41.2  129.9   0.3432   1.0    9.4	4U 1735-44                    
276.0682 -30.2768    6.2  47.1  152.4  -0.6545  -1.9    9.2	H1820-303                     
285.1301 -24.7392    0.0  47.9  165.6   0.2498   0.8   12.0	HT1900.1-2455                 
122.0331 -65.4158    3.0  51.2   31.7   2.1894   3.8 ------	UNKNOWN                       
176.4752 -83.8875    3.0  33.9   51.3   0.7153   3.8 ------	UNKNOWN                       
 15.6956 -72.7017    0.2  19.9    8.4   8.1926  72.4 ------	UNKNOWN                       
330.8671 -11.9719    2.9  49.7 -133.3   2.1688   4.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
55.252600 962.377000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
264.6485 -44.6010    5.2  53.5  157.3   6.7691   2.2    9.9	4U 1735-44                    
 63.4289 -73.4413    2.8  13.6   37.4   2.0784   4.1 ------	UNKNOWN                       
284.2304 -38.3343    3.4  54.1  177.0   7.0620   3.3 ------	UNKNOWN                       
 16.6505 -36.5788    4.1  36.1  -77.1   4.4449   2.8 ------	UNKNOWN