GRB070220: 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: Mon Jan 20 11:29:01 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger261299
======================================================================

  Trigger: 00261299      Segment: 000

  BAT Trigger Time: 193639474.688   [s; MET]
      Trigger Stop: 193639475.712   [s; MET]
               UTC: 2007-02-20T04:44:32.912080    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 34.8193073293135   Dec: 68.8182975953661  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    10.51
     Image Trigger?:     NO
     Rate S/N Ratio:     20.8326666559997  [ if not an image trigger ]
     Image S/N Ratio:    10.51

  Analysis Position:   [ source = BAT ]
    RA: 34.8193073293135   Dec: 68.8182975953661  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 34.7970294812238   Dec: 68.8026811112005  [deg; J2000]  
        { 02h 19m 11.3s , +68d 48' 09.7" }
         +/- 0.671473247251799 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.158854406686084 [arcmin] (formal 1-sigma fit error)
    SNR: 53.7304176991178
 
  Angular difference between the analysis and refined position is 1.054219 arcmin
 
  Partial Coding Fraction: 0.640625    [ including projection effects ]

  Duration
     T90: 125.396000027657 +/- 20.6414407381691
        Measured from: -1.26399999856949
                   to: 124.132000029087     [s; relative to TRIGTIME]
     T50: 34.8600000143051 +/- 1.66012047274466
        Measured from: 8.95199999213219
                   to: 43.8120000064373     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 11.8600000143051     
                   to: 12.8600000143051     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -17.1200000047684     
                   to: 239.087999999523     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     3.918818   5.641653   4.975998   1.627286
           0.087647   0.093529   0.086604   0.082865 [error]
 Peak      0.141334   0.247157   0.252257   0.079830
           0.008838   0.010466   0.010715   0.009097 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100  256.208  -17.120  239.088
T90   125.396   -1.264  124.132
T50    34.860    8.952   43.812
Peak    1.000   11.860   12.860
 
 
====== 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      -1.373    -0.042      0.042       -           -               -         4.24e-03     -9.01e-05          9.00e-05      48.270   57
CPL     -1.334    -0.062      0.139      994.876    -994.876      -994.876      4.40e-03     -2.42e-04          6.22e-04      48.330   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      -1.158     -0.080     0.080       -           -               -         5.03e-02     -2.28e-03          2.28e-03      54.600   57
CPL     -0.913     -0.275     0.330      248.253      N/A           N/A         6.52e-02        N/A               N/A         52.780   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   1.23e-06  2.44e-06  3.78e-06  1.28e-05  1.06e-05  2.02e-05   erg/cm2
      90%_error_low -5.70e-08 -6.49e-08 -9.37e-08 -7.51e-07 -2.33e-07 -7.87e-07   erg/cm2
      90%_error_hi   5.82e-08  6.47e-08  9.35e-08  7.84e-07  2.33e-07  8.14e-07   erg/cm2
Peak flux       PL   1.49e+00  1.84e+00  1.65e+00  2.56e+00  5.88e+00  7.55e+00   ph/cm2/s
      90%_error_low -1.33e-01 -1.01e-01 -8.55e-02 -2.74e-01 -2.74e-01 -3.63e-01   ph/cm2/s
      90%_error_hi   1.37e-01  9.99e-02  8.50e-02  2.95e-01  2.75e-01  3.66e-01   ph/cm2/s
 
Fluence        CPL   1.23e-06  2.44e-06  3.85e-06  1.26e-05  1.05e-05  1.99e-05   erg/cm2
      90%_error_low -8.24e-08 -5.80e-08 -1.73e-07 -2.36e-06 -2.38e-07 -2.27e-06   erg/cm2
      90%_error_hi   3.97e-08  6.69e-08  3.52e-08  6.43e-07  2.40e-07  1.03e-06   erg/cm2
Peak flux      CPL   1.41e+00  1.87e+00  1.70e+00  1.98e+00  5.82e+00  6.97e+00   ph/cm2/s
      90%_error_low -1.68e-01 -1.08e-01 -1.04e-01 -5.32e-01 -2.85e-01 -6.13e-01   ph/cm2/s
      90%_error_hi   1.72e-01  1.09e-01  1.05e-01  6.78e-01  2.85e-01  7.65e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
   34.7970    68.8027   0.0036    38.4674  -167.8726         4.9412357     53.730 TRIG_00261299                 
 
Foreground time interval of the image:
-17.120  10.813 (delta_t =  27.933 [sec])
Background time interval of the image:
-239.688 -17.120 (delta_t = 222.568 [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  -17.120 sec. to  239.088 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.37253     ( -0.0419239   0.0420061 )
Norm@50keV  : 4.23690E-03    ( -9.00816e-05   9.00321e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.27 using 59 PHA bins.
# Reduced chi-squared =         0.8468 for     57 degrees of freedom 
# Null hypothesis probability =   7.883612e-01
 
Photon flux (15-150 keV)    in 256.2 sec: 0.512858 ( -0.01233  0.012393 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.05506e-05 ( -2.32564e-07  2.32836e-07 ) ergs/cm2
 

Cutoff power-law model

Time interval is from  -17.120 sec. to  239.088 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.36887     ( -0.061566   0.138871 )
Epeak [keV] : 9998.45      ( -9998.43 -9998.43 )
Norm@50keV  : 4.25259E-03    ( -8.97721e-05   0.00077407 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.26 using 59 PHA bins.
# Reduced chi-squared =         0.8617 for     56 degrees of freedom 
# Null hypothesis probability =   7.594844e-01
 
Photon flux (15-150 keV)    in 256.2 sec: 0.512342 ( -0.01424  0.012872 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.05429e-05 ( -2.37859e-07  2.40102e-07 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from   11.860 sec. to   12.860 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.15832     ( -0.0795549   0.0799316 )
Norm@50keV  : 5.03378E-02    ( -0.00227607   0.00227564 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          54.60 using 59 PHA bins.
# Reduced chi-squared =         0.9579 for     57 degrees of freedom 
# Null hypothesis probability =   5.656639e-01
 
Photon flux (15-150 keV)    in 1 sec: 5.87632 ( -0.27429  0.27458 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.16964e-07 ( -2.58187e-08  2.59112e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   11.860 sec. to   12.860 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.913451     ( -0.275435   0.330435 )
Epeak [keV] : 248.253      (   )
Norm@50keV  : 6.52102E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          52.78 using 59 PHA bins.
# Reduced chi-squared =         0.9424 for     56 degrees of freedom 
# Null hypothesis probability =   5.976964e-01
 
Photon flux (15-150 keV)    in 1 sec: 5.81520 ( -0.2847  0.28472 ) ph/cm2/s
Energy fluence (15-150 keV)             : 5.10529e-07 ( -2.74035e-08  2.727e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 125.396 sec.
Hardness ratio (energy fluence ratio) = 1.54486275081

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

S(15-50 keV)  = 3.673972e-06
S(50-150 keV) = 6.876649e-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 = -7.767760942774423E-01, IMY = 1.669142813858942E-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:
-239.688000 -17.120000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3621  35.5028    7.6  34.0   -3.7   0.3434   1.5   10.7	Her X-1                       
299.5797  35.2070    1.2  40.3  -65.5   4.6538   9.4    0.6	Cyg X-1                       
308.0593  40.9423    3.5  37.6  -78.8   1.6311   3.3    2.4	Cyg X-3                       
 34.9018  59.4141    2.5  47.2 -162.8   1.4937   4.7 ------	UNKNOWN                       

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

Time interval of the image:
-17.120000 10.812600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.2802  35.2088    0.0  34.3   -3.6  -0.0450  -0.5   11.8	Her X-1                       
299.5076  35.3285 2700.0  40.2  -65.4   0.0005   0.0    8.6	Cyg X-1                       
308.0458  40.8227   10.0  37.7  -78.7  -0.2204  -1.2    8.3	Cyg X-3                       
 34.7970  68.8027    0.2  38.5 -167.9   4.9414  53.7 ------	UNKNOWN                       
305.0329  47.0866    2.1  31.1  -80.3   0.5988   5.4 ------	UNKNOWN                       
  3.6108  49.2526    2.5  49.0 -135.1   1.4272   4.6 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
68.012590 962.444300
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 81.4373  26.4792    3.0  50.4  152.7   6.9961   3.9 ------	UNKNOWN                       
118.1616  77.0661    2.7  23.3   64.5   2.2230   4.3 ------	UNKNOWN                       
 34.8283  68.8082    1.1   0.0  153.1   4.4116  10.1 ------	UNKNOWN                       
  6.9739  43.3124    3.1  29.3 -105.7   2.6660   3.7 ------	UNKNOWN