GRB080516: 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 02:04:31 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger311762
======================================================================

  Trigger: 00311762      Segment: 000

  BAT Trigger Time: 232589829.824   [s; MET]
      Trigger Stop: 232589830.336   [s; MET]
               UTC: 2008-05-16T00:17:07.030760    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 120.629533847551   Dec: -26.1760175623149  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.61
     Image Trigger?:     NO
     Rate S/N Ratio:     15.0665191733194  [ if not an image trigger ]
     Image S/N Ratio:    8.61

  Analysis Position:   [ source = BAT ]
    RA: 120.629533847551   Dec: -26.1760175623149  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 120.661366398219   Dec: -26.1488751984184  [deg; J2000]  
        { 08h 02m 38.7s , -26d 08' 56.0" }
         +/- 2.17010907859261 [arcmin] (estimated 90% radius based on SNR)
         +/- 1.21551020393041 [arcmin] (formal 1-sigma fit error)
    SNR: 10.0561196413796
 
  Angular difference between the analysis and refined position is 2.364505 arcmin
 
  Partial Coding Fraction: 0.3828125    [ including projection effects ]

  Duration
     T90: 5.76400002837181 +/- 0.223212908197741
        Measured from: 0.15599998831749
                   to: 5.9200000166893     [s; relative to TRIGTIME]
     T50: 5.0160000026226 +/- 0.415716250511535
        Measured from: 0.444000005722046
                   to: 5.46000000834465     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.0519999861717224     
                   to: 1.05199998617172     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0839999914169312     
                   to: 6.05599999427795     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.142337   0.167476   0.096463   0.016133
           0.021073   0.022218   0.019634   0.016992 [error]
 Peak      0.041052   0.080558   0.057517   0.010654
           0.009324   0.010127   0.008997   0.007418 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    5.972    0.084    6.056
T90     5.764    0.156    5.920
T50     5.016    0.444    5.460
Peak    1.000    0.052    1.052
 
 
====== 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      -1.820    -0.271      0.255       -           -               -         4.86e-03     -8.18e-04          7.94e-04      59.140   57
CPL     -1.557    -0.700      1.188       76.567     -76.355       -76.567      6.78e-03        N/A               N/A         58.930   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      -1.457     -0.232     0.231       -           -               -         1.37e-02     -2.02e-03          2.01e-03      63.890   57
CPL     -0.268     -1.066     1.454       71.259     -18.082       164.643      5.64e-02     -5.64e-02          2.58e-01      60.190   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   5.01e-08  7.58e-08  8.59e-08  1.85e-07  2.67e-07  3.97e-07   erg/cm2
      90%_error_low -1.05e-08 -1.08e-08 -1.93e-08 -7.26e-08 -4.47e-08 -9.46e-08   erg/cm2
      90%_error_hi   1.10e-08  1.08e-08  1.94e-08  9.77e-08  4.55e-08  1.14e-07   erg/cm2
Peak flux       PL   5.43e-01  5.60e-01  4.08e-01  4.78e-01  1.70e+00  1.99e+00   ph/cm2/s
      90%_error_low -1.28e-01 -8.83e-02 -7.19e-02 -1.48e-01 -2.52e-01 -2.92e-01   ph/cm2/s
      90%_error_hi   1.36e-01  8.74e-02  7.12e-02  1.82e-01  2.53e-01  2.93e-01   ph/cm2/s
 
Fluence        CPL   4.87e-08  7.84e-08  8.64e-08  1.19e-07  2.61e-07  3.32e-07   erg/cm2
      90%_error_low -1.21e-08 -1.29e-08 -2.04e-08 -9.37e-08 -4.97e-08 -1.10e-07   erg/cm2
      90%_error_hi   1.21e-08  1.48e-08  2.05e-08  1.27e-07  4.49e-08  1.12e-07   erg/cm2
Peak flux      CPL   4.47e-01  6.31e-01  4.45e-01  1.56e-01  1.64e+00  1.68e+00   ph/cm2/s
      90%_error_low -1.50e-01 -1.12e-01 -8.60e-02 -1.06e-01 -2.60e-01 -2.85e-01   ph/cm2/s
      90%_error_hi   1.59e-01  1.19e-01  8.73e-02  2.67e-01  2.59e-01  3.33e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  120.6614   -26.1489   0.0191    38.7053   154.8100         0.4024027     10.056 TRIG_00311762                 
 
Foreground time interval of the image:
  0.084   6.056 (delta_t =   5.972 [sec])
Background time interval of the image:
-239.824 -65.655 (delta_t = 174.169 [sec])
-64.824   0.084 (delta_t =  64.908 [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    0.084 sec. to    6.056 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.82046     ( -0.270577   0.254713 )
Norm@50keV  : 4.86370E-03    ( -0.000818354   0.000794245 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.14 using 59 PHA bins.
# Reduced chi-squared =          1.038 for     57 degrees of freedom 
# Null hypothesis probability =   3.973626e-01
 
Photon flux (15-150 keV)    in 5.972 sec: 0.675633 ( -0.096911  0.096973 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.67276e-07 ( -4.46784e-08  4.55409e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.084 sec. to    6.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.55746     ( -0.699755   1.18775 )
Epeak [keV] : 76.5675      ( -76.3549 -76.5674 )
Norm@50keV  : 6.77900E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.93 using 59 PHA bins.
# Reduced chi-squared =          1.052 for     56 degrees of freedom 
# Null hypothesis probability =   3.687305e-01
 
Photon flux (15-150 keV)    in 5.972 sec: 0.669122 ( -0.10035  0.099786 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.61331e-07 ( -4.96944e-08  4.48939e-08 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    0.052 sec. to    1.052 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.45682     ( -0.231912   0.23077 )
Norm@50keV  : 1.37446E-02    ( -0.00202049   0.00201417 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          63.89 using 59 PHA bins.
# Reduced chi-squared =          1.121 for     57 degrees of freedom 
# Null hypothesis probability =   2.473386e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.69674 ( -0.25191  0.2525 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.3138e-07 ( -2.07533e-08  2.09376e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.052 sec. to    1.052 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.267739     ( -1.06562   1.4537 )
Epeak [keV] : 71.2591      ( -18.0807 164.644 )
Norm@50keV  : 5.63819E-02    ( -0.0563855   0.258181 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.19 using 59 PHA bins.
# Reduced chi-squared =          1.075 for     56 degrees of freedom 
# Null hypothesis probability =   3.267838e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.63690 ( -0.25958  0.25937 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.21593e-07 ( -2.28992e-08  2.31575e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 5.764 sec.
Hardness ratio (energy fluence ratio) = 1.13255690111

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

S(15-50 keV)  = 1.2597445e-07
S(50-150 keV) = 1.4129744e-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 = -7.251013151863204E-01, IMY = -3.410517312909804E-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:
-239.824000 -65.654800
-64.824000 0.084000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6305  22.0240    0.5  35.0  -92.2  10.4337  24.3    0.6	Crab                          
158.9303  18.7139    2.8  38.8   52.8   1.7250   4.2 ------	UNKNOWN                       
164.9035  57.4247    3.2  56.7    4.7   3.7985   3.6 ------	UNKNOWN                       
108.9960  -1.6591    2.9  17.3 -167.1   0.6223   3.9 ------	UNKNOWN                       
148.1573  66.5624    2.6  57.4   -9.6   3.5508   4.3 ------	UNKNOWN                       
 88.1625 -28.2782    2.6  50.6 -167.0   1.8318   4.5 ------	UNKNOWN                       

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

Time interval of the image:
0.084000 6.056000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.4855  22.0936    5.5  35.2  -92.1  -0.1004  -2.1    9.5	Crab                          
119.1174 -31.3095    2.2  43.8  157.0   0.2815   5.3 ------	UNKNOWN                       
120.6613 -26.1489    1.1  38.7  154.8   0.4021  10.0 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
66.876610 962.274200
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
135.5126 -40.5765    1.1  19.0  115.9   5.4663  10.7    1.5	Vela X-1                      
 89.9315 -67.5319    2.3  45.4  168.6   5.3786   5.1 ------	UNKNOWN                       
 70.1656 -69.7376    2.8  52.3  172.4   6.6566   4.1 ------	UNKNOWN                       
108.4363 -46.0654    2.9  22.2  175.6   1.7083   3.9 ------	UNKNOWN                       
 53.7984 -66.0701    4.4  56.9  179.2   8.3807   2.7 ------	UNKNOWN                       
 87.6726 -41.9093    2.7  31.3 -156.0   2.2792   4.3 ------	UNKNOWN                       
137.7218  28.9122    2.8  57.5   -9.5  10.5551   4.1 ------	UNKNOWN                       
105.1478   5.7571    2.2  35.3  -54.7   3.8796   5.3 ------	UNKNOWN