GRB150402A: 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 GROUND-DETECTED GRB DATA PROCESSING REPORT                 
            (This burst occurred during telescope slew)                  
    Process Script Ver: batgrbproduct v2.46
    Process Start Time: Fri Apr  3 13:20:05 EDT 2015
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger636865
======================================================================

  Trigger: 00636865      Segment: 000

  BAT Trigger Time: 449627880.0
               UTC: 2015-04-02T00:37:46.694   [includes UTCF correction]
       Where From?: Ground analysis (best_duration.txt)
  NOTE: BAT trigger time for ground-detected burst during slew is the T100 start time.
 
  Analysis Position:   [ source = GCN ]
    RA: 173.604   Dec: 40.988  [deg; J2000]
 
  Refined Position:   [ source = BAT mosaic image ]
    RA: 173.625622355006   Dec: 40.9819564484979  [deg; J2000]
        { 11h 34m 30.1s , +40d 58' 55.0" }
        +/- 2.58845709262 [arcmin] (estimated 90% radius based on SNR)
    SNR: 7.81837808864
 
 
  Angular difference between the analysis and refined position is 1.044315 arcmin
 
  Partial Coding Fraction: Unavailable because the burst occurred during slew.
 
  Duration
     T90: 14.4000000357628 +/- 1.6
        Measured from: 0
                   to: 14.4     [s; relative to TRIGTIME]
     T50: 8.00000005960464 +/- 1.6
        Measured from: 3.2
                   to: 11.2     [s; relative to TRIGTIME]
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   14.400    0.000   14.400
T90    14.400    0.000   14.400
T50     8.000    3.200   11.200
Peak    1.000   13.100   14.100
 
 
====== 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      -2.277    -0.521      0.442       -           -               -         1.88e-03     -6.66e-04          6.42e-04      53.040   57
CPL     -1.889     N/A        N/A          10.208      N/A           N/A         3.34e-03        N/A               N/A         53.090   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      N/A         N/A       N/A          -           -               -           N/A           N/A               N/A         N/A        N/A   
CPL     N/A         N/A       N/A          N/A         N/A           N/A           N/A           N/A               N/A         N/A        N/A   
 
 
=== 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   4.05e-08  4.65e-08  3.84e-08  5.32e-08  1.45e-07  1.78e-07   erg/cm2
      90%_error_low -1.16e-08 -1.18e-08 -1.71e-08 -3.46e-08 -4.08e-08 -6.22e-08   erg/cm2
      90%_error_hi   1.18e-08  1.14e-08  1.91e-08  6.39e-08  4.34e-08  8.41e-08   erg/cm2
Peak flux       PL     N/A      N/A      N/A      N/A      N/A      N/A     ph/cm2/s

Special notes of this burst

Image

Note1: The mosaic image is made with timebin = 0.05 s; energybin = 15-100 keV

Note2: The mosaic image uses Galactic coordinate.

#RAcent DECcent POSerr Theta  Phi  Peak_Cts  SNR Name
173.626 40.982 0.009 20.049 -76.806 0.063 7.818 UNKNOWN
 
Image time interval: 0.000 to 3.000 [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.

Best duration plot

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    0.000 sec. to    8.070 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.27697     ( -0.520578   0.441912 )
Norm@50keV  : 1.88229E-03    ( -0.000666231   0.000642283 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.04 using 59 PHA bins.
# Reduced chi-squared =         0.9306 for     57 degrees of freedom 
# Null hypothesis probability =   6.242896e-01
 
Photon flux (15-150 keV)    in 8.07 sec: 0.324820 ( -0.073897  0.073903 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.44592e-07 ( -4.08262e-08  4.33674e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    0.000 sec. to    8.070 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.88872     (       )
Epeak [keV] : 10.2078      (   )
Norm@50keV  : 3.34049E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.09 using 59 PHA bins.
# Reduced chi-squared =         0.9480 for     56 degrees of freedom 
# Null hypothesis probability =   5.857182e-01
 
Photon flux (15-150 keV)    in 8.07 sec: 0.324828 ( -0.073852  0.073856 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.38913e-07 ( -4.84869e-08  4.96662e-08 ) ergs/cm2
 

1-s peak spectrum fit

1-s peak spectrum unavailable, likely because there are no event data in the 1-s peak range.

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 14.4 sec.
Hardness ratio (energy fluence ratio) = 0.825372539185

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

S(15-50 keV)  = 8.695463e-08
S(50-150 keV) = 5.763666e-08

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

Mask shadow pattern unavailable because this burst occurs during telescope slews.

Spacecraft aspect plot