GRB160127A: 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 Mar 17 18:51:30 EDT 2016
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger671828
======================================================================

  Trigger: 00671828      Segment: 000

  BAT Trigger Time: 475577003.072   [s; MET]
      Trigger Stop: 475577004.096   [s; MET]
               UTC: 2016-01-27T08:43:07.315740    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 225.956116498615   Dec: 0.0890830115484875  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.7
     Image Trigger?:     NO
     Rate S/N Ratio:     11.13552872566  [ if not an image trigger ]
     Image S/N Ratio:    7.7

  Analysis Position:   [ source = BAT ]
    RA: 225.956116498615   Dec: 0.0890830115484875  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 225.965815369058   Dec: 0.0795022165088216  [deg; J2000]  
        { 15h 03m 51.8s , +00d 04' 46.2" }
         +/- 1.79449983656284 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.704551751244017 [arcmin] (formal 1-sigma fit error)
    SNR: 13.1929543970037
 
  Angular difference between the analysis and refined position is 0.817982 arcmin
 
  Partial Coding Fraction: 0.4179688    [ including projection effects ]

  Duration
     T90: 6.15599989891052 +/- 0.936657860780595
        Measured from: -0.708000004291534
                   to: 5.44799989461899     [s; relative to TRIGTIME]
     T50: 3.57199996709824 +/- 0.672059531867363
        Measured from: 0.74399995803833
                   to: 4.31599992513657     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 3.34399998188019     
                   to: 4.34399998188019     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -1.43600004911423     
                   to: 5.7039999961853     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.357084   0.306302   0.091129   0.000785
           0.030976   0.030671   0.025385   0.021638 [error]
 Peak      0.081051   0.060077   0.038366   0.005418
           0.012629   0.012282   0.010053   0.007853 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    7.140   -1.436    5.704
T90     6.156   -0.708    5.448
T50     3.572    0.744    4.316
Peak    1.000    3.344    4.344
 
 
====== 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      -2.433    -0.243      0.223       -           -               -         5.19e-03     -9.29e-04          9.21e-04      50.220   57
CPL     -0.986    -0.898      1.329       25.593      N/A           N/A         4.16e-02        N/A               N/A         44.140   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      -2.255     -0.393     0.340       -           -               -         8.52e-03     -2.46e-03          2.40e-03      64.420   57
CPL     -0.498     -1.460     1.925       35.012      N/A           N/A         9.26e-02        N/A               N/A         59.970   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   1.14e-07  1.20e-07  8.89e-08  1.06e-07  3.64e-07  4.30e-07   erg/cm2
      90%_error_low -1.62e-08 -1.52e-08 -2.08e-08 -4.06e-08 -5.04e-08 -7.38e-08   erg/cm2
      90%_error_hi   1.64e-08  1.50e-08  2.21e-08  5.49e-08  5.19e-08  8.39e-08   erg/cm2
Peak flux       PL   7.29e-01  4.71e-01  1.97e-01  1.13e-01  1.45e+00  1.51e+00   ph/cm2/s
      90%_error_low -1.86e-01 -1.02e-01 -6.98e-02 -5.94e-02 -3.04e-01 -3.18e-01   ph/cm2/s
      90%_error_hi   1.93e-01  1.01e-01  7.36e-02  8.73e-02  3.04e-01  3.19e-01   ph/cm2/s
 
Fluence        CPL    N/A      N/A      N/A      N/A      N/A      N/A      erg/cm2
      90%_error_low -1.62e-08 -1.52e-08 -2.08e-08 -4.06e-08 -5.04e-08 -7.38e-08   erg/cm2
      90%_error_hi   1.64e-08  1.50e-08  2.21e-08  5.49e-08  5.19e-08  8.39e-08   erg/cm2
Peak flux      CPL   6.36e-01  5.86e-01  1.96e-01  1.93e-02  1.44e+00  1.43e+00   ph/cm2/s
      90%_error_low -2.22e-01 -1.38e-01 -8.98e-02 -1.93e-02 -3.01e-01 -2.98e-01   ph/cm2/s
      90%_error_hi   2.18e-01  1.43e-01  9.22e-02  6.59e-02  3.00e-01  3.08e-01   ph/cm2/s
 
======================================================================

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  225.9658     0.0795   0.0146    32.1552  -109.8064         0.7811506     13.193 TRIG_00671828                 
 
Foreground time interval of the image:
 -1.436   5.704 (delta_t =   7.140 [sec])
Background time interval of the image:
-239.072  -1.436 (delta_t = 237.636 [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   -1.436 sec. to    5.704 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.43252     ( -0.243464   0.223304 )
Norm@50keV  : 5.18734E-03    ( -0.000929417   0.000920944 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          50.22 using 59 PHA bins.
# Reduced chi-squared =         0.8810 for     57 degrees of freedom 
# Null hypothesis probability =   7.254129e-01
 
Photon flux (15-150 keV)    in 7.14 sec: 0.978500 ( -0.112169  0.11217 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.6414e-07 ( -5.03651e-08  5.18551e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from   -1.436 sec. to    5.704 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.986438     ( -0.898092   1.3295 )
Epeak [keV] : 25.5934      (   )
Norm@50keV  : 4.15770E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.14 using 59 PHA bins.
# Reduced chi-squared =         0.7882 for     56 degrees of freedom 
# Null hypothesis probability =   8.742817e-01
 
Photon flux (15-150 keV)    in 7.14 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2
 

1-s peak spectrum fit

Power-law model

Time interval is from    3.344 sec. to    4.344 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -2.25497     ( -0.392635   0.340579 )
Norm@50keV  : 8.52384E-03    ( -0.0024608   0.00240409 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.42 using 59 PHA bins.
# Reduced chi-squared =          1.130 for     57 degrees of freedom 
# Null hypothesis probability =   2.329904e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.45337 ( -0.3045  0.30449 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.08202e-08 ( -1.97457e-08  2.04659e-08 ) ergs/cm2
 

Cutoff power-law model

Time interval is from    3.344 sec. to    4.344 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.498128     ( -1.45459   1.93017 )
Epeak [keV] : 35.0120      (   )
Norm@50keV  : 9.26196E-02    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          59.97 using 59 PHA bins.
# Reduced chi-squared =          1.071 for     56 degrees of freedom 
# Null hypothesis probability =   3.338199e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.43701 ( -0.3007  0.30041 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.65086e-08 ( -1.84536e-08  1.92064e-08 ) ergs/cm2
 

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 6.156 sec.
Hardness ratio (energy fluence ratio) = 0.741037206785

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

S(15-50 keV)  = 2.343906e-07
S(50-150 keV) = 1.297516e-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 = -2.130115013309690E-01, IMY = 5.914544981454837E-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:
-239.072000 -1.436000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
163.5627 -42.2802    2.4  50.4    9.1   2.8358   4.7 ------	UNKNOWN                       
216.7139 -33.0149    2.5  39.5  -50.7   2.1702   4.6 ------	UNKNOWN                       
225.7382 -11.7509    2.3  33.8  -88.2   2.3024   4.9 ------	UNKNOWN                       

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

Time interval of the image:
-1.436000 5.704000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
154.5416   5.1872    2.6  39.5   78.3   0.6188   4.5 ------	UNKNOWN                       
159.3237 -28.5383    2.6  43.7   26.3   0.3211   4.5 ------	UNKNOWN                       
225.9658   0.0795    0.9  32.2 -109.8   0.7812  13.2 ------	UNKNOWN                       

Post-slew image of 15-350 keV band

Time interval of the image:
62.828600 962.998800
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
244.9793 -15.6311    0.2  24.5  -67.7  70.1824  60.1    0.5	Sco X-1                       
254.5696  35.4592    6.7  44.3 -164.5  -3.2289  -1.7    8.9	Her X-1                       
255.8578 -37.7256    0.0  46.8  -51.3  -5.2593  -1.2    9.4	4U 1700-377                   
256.5032 -36.4435    9.5  46.2  -53.0   5.3671   1.2    3.5	GX 349+2                      
241.8848  45.2197    4.7  47.3  176.8   6.2162   2.5 ------	UNKNOWN                       
244.6206  19.9070    2.3  27.0 -156.9   5.3522   5.0 ------	UNKNOWN                       
219.6895 -57.7941    3.0  58.1  -14.6  17.5143   3.9 ------	UNKNOWN