batgrbproduct analysis for trigger=373458

batgrbproduct Analysis for Trigger=373458

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 (local time): Sun Jan 19 13:30:44 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger373458
======================================================================

  Trigger: 00373458      Segment: 000

  BAT Trigger Time: 277767409.856   [s; MET]
      Trigger Stop: 277767410.88   [s; MET]
               UTC: 2009-10-20T21:36:44.667340    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 175.715548275446   Dec: 50.9720400823411  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    17.7
     Image Trigger?:     NO
     Rate S/N Ratio:     32.4191301548947  [ if not an image trigger ]
     Image S/N Ratio:    17.7

  Flight Position:   [ source = BAT ]
    RA: 175.715548275446   Dec: 50.9720400823411  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 175.726835303108   Dec: 50.9774125819927  [deg; J2000]  
        { 11h 42m 54.4s , +50d 58' 38.7" }
         +/- 0.757587947777491 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.243574151077148 [arcmin] (formal 1-sigma fit error)
    SNR: 45.2227397624376
 
  Angular difference between Flight and Ground position is 0.534551 arcmin
 
  Partial Coding Fraction: 0.4335938    [ including projection effects ]

  Duration
     T90: 38.9199999570847 +/- 4.88857609247848
        Measured from: -4.08399999141693
                   to: 34.8359999656677     [s; relative to TRIGTIME]
     T50: 9.59599995613098 +/- 1.17872472366142
        Measured from: 1.1599999666214
                   to: 10.7559999227524     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 1.14399999380112     
                   to: 2.14399999380112     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -8.47600001096725     
                   to: 48.2639999985695     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     1.545767   2.029628   1.723886   0.471002
           0.058557   0.063002   0.057686   0.052382 [error]
 Peak      0.106396   0.163347   0.178704   0.062414
           0.010333   0.011840   0.011522   0.009940 [error]

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

======================================================================
 
=== 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   Power-law 5.30e-07 9.55e-07 1.32e-06 3.80e-06 3.80e-06 6.60e-06   erg/cm2
              Error 3.65e-08 3.79e-08 5.97e-08 3.90e-07 1.44e-07 4.24e-07   erg/cm2
Peak flux Power-law 1.09e+00 1.32e+00 1.16e+00 1.76e+00 4.18e+00 5.32e+00   ph/cm2/s
              Error 1.53e-01 1.13e-01 9.33e-02 3.03e-01 3.08e-01 3.96e-01   ph/cm2/s
 
Fluence   Cutoff-PL 5.20e-07 9.60e-07 1.33e-06 3.38e-06 3.78e-06 6.19e-06   erg/cm2
              Error 4.50e-08 4.13e-08 6.53e-08 8.02e-07 1.19e-07 8.96e-07   erg/cm2
Peak flux Cutoff-PL 1.05e+00 1.30e+00 1.17e+00 1.81e+00 4.16e+00 5.34e+00   ph/cm2/s
              Error 1.64e-01 1.22e-01 1.08e-01 4.72e-01 3.20e-01 6.07e-01   ph/cm2/s
 
Fluence        Band -------- -------- -------- -------- -------- --------   erg/cm2
              Error -------- -------- -------- -------- -------- --------   erg/cm2
Peak flux      Band -------- -------- -------- -------- -------- --------   ph/cm2/s
              Error -------- -------- -------- -------- -------- --------   ph/cm2/s

 
=== Time-averaged spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.532    0.067    -      -           7.10e-03 2.52e-04   41.390 57
CPL   1.451    0.199     362.8    0.0      7.75e-03 1.65e-03   41.080 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.184    0.124    -      -           3.57e-02 2.53e-03   64.460 57
CPL   1.179    0.289    9996.2    0.0      3.58e-02 1.36e-02   64.460 56
 
Model      : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index   : photon index: E^-{Ph_index} (minus sign is not included in the 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 PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2       : Chi-Squared
dof        : degree of freedom

 
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
 
T90 in the 50-300 keV band: 31.872000 sec.
T50 in the 50-300 keV band: 7.744000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   56.740   -8.476   48.264
T90    38.920   -4.084   34.836
T50     9.596    1.160   10.756
Peak    1.000    1.144    2.144

Click here for the BAT GCN circular template

Special notes of this burst

Image

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

#   RAcent    DECcent   POSerr    Theta     Phi              Peak Cts       SNR   Name
  175.7268    50.9774   0.0043    41.1310  -148.6576         4.5729407     45.223 TRIG_00373458                 
 
Foreground time interval of the image:
 -8.476  11.645 (delta_t =  20.121 [sec])
Background time interval of the image:
-239.856  -8.476 (delta_t = 231.380 [sec])

Lightcurves

Notes:

1) The mask-weighted light curves are using the flight position.
2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
5) Time of each bin is in the middle of the bin.

1 s binning

From T0-310 s to T0+310 s

From T100_start - 20 s to T100_end + 30 s

Full time interval

64 ms binning

Full time interval

From T100_start to T100_end

From T0-5 sec to T0+5 sec

16 ms binning

From T100_start-5 s to T100_start+5 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

8 ms binning

From T100_start-3 s to T100_start+3 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

2 ms binning

From T100_start-1 s to T100_start+1 s

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

SN=5 or 10 sec. binning (whichever binning is satisfied first)

SN=5 or 10 sec. binning (T < 200 sec)

Quad-rate summed light curves (from T0-300s to T0+1000s)

Spectral Evolution

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   -8.476 sec. to   48.264 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.53238     ( -0.0670696   0.0672185 )
Norm@50keV  : 7.09547E-03    ( -0.000251872   0.000251693 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.39 using 59 PHA bins.
# Reduced chi-squared =         0.7262 for     57 degrees of freedom 
# Null hypothesis probability =   9.403484e-01
 
Photon flux (15-150 keV)    in 56.74 sec: 0.893731 ( -0.0342632  0.0344156 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.79988e-06 ( -1.43833e-07  1.44332e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -8.476 sec. to   48.264 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.45077     ( -0.260692   0.137092 )
Epeak [keV] : 362.833      ( -362.832 -362.832 )
Norm@50keV  : 7.74845E-03    ( -0.000862609   0.00243205 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.08 using 59 PHA bins.
# Reduced chi-squared =         0.7336 for     56 degrees of freedom 
# Null hypothesis probability =   9.324375e-01
 
Photon flux (15-150 keV)    in 56.74 sec: 0.888510 ( -0.037399  0.037357 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.78043e-06 ( -1.58197e-07  7.91807e-08 ) ergs/cm2

Band function

Time interval is from   -8.476 sec. to   48.264 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.45998   ( 1.01582   5.94974 )
beta        : -9.18666    ( 9.36203   19.362 )
Epeak [keV] : 396.251      ( -189.827 -396.418 )
Norm@50keV   : 7.67914E-03    ( -0.000794752   0.00201553 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          41.09 using 59 PHA bins.
# Reduced chi-squared =         0.7470 for     55 degrees of freedom 
# Null hypothesis probability =   9.182794e-01
 
Photon flux (15-150 keV)    in 56.74 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 16.3974  (  )
R^2/D10^2   : 7.08634E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         228.87 using 59 PHA bins.
# Reduced chi-squared =         4.0153 for     57 degrees of freedom 
# Null hypothesis probability =   1.864716e-22
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.223e-07   1.597e-08
25- 50  9.548e-07   4.851e-08
50-150  1.811e-06   1.251e-07
15-150  2.988e-06   1.271e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (      )
Norm        : 3.63513       (-0.128346     0.128345)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.97 using 59 PHA bins.
# Reduced chi-squared =         0.7890 for     57 degrees of freedom 
# Null hypothesis probability =   8.756484e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.137e-07   2.009e-08
25- 50  9.882e-07   3.915e-08
50-150  2.167e-06   8.795e-08
15-150  3.669e-06   1.436e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.29730        (-0.785451      0.897483)
R1^2/D10^2  : 1.34825        (-0.522401      0.923678)
kT2 [keV]   : 25.5392        (-2.44599      3.24122)
R2^2/D10^2  : 1.27193E-02    (-0.00444236   0.00566938)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.81 using 59 PHA bins.
# Reduced chi-squared =         0.7965 for     55 degrees of freedom 
# Null hypothesis probability =   8.610164e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  5.115e-07   7.717e-08
25- 50  9.400e-07   7.092e-08
50-150  2.288e-06   2.020e-07
15-150  3.739e-06   2.718e-07

Peak spectrum fit

Power-law model

Time interval is from    1.144 sec. to    2.144 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.18388     ( -0.125133   0.123677 )
Norm@50keV  : 3.56719E-02    ( -0.00252896   0.00252775 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.46 using 59 PHA bins.
# Reduced chi-squared =          1.131 for     57 degrees of freedom 
# Null hypothesis probability =   2.319313e-01
 
Photon flux (15-150 keV)    in 1 sec: 4.17792 ( -0.307655  0.308281 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.63573e-07 ( -2.81441e-08  2.82836e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    1.144 sec. to    2.144 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.17927     ( -0.428646   0.148394 )
Epeak [keV] : 9996.21      (   )
Norm@50keV  : 3.58490E-02    ( -0.00254348   0.0246875 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.46 using 59 PHA bins.
# Reduced chi-squared =          1.151 for     56 degrees of freedom 
# Null hypothesis probability =   2.048061e-01
 
Photon flux (15-150 keV)    in 1 sec: 4.15634 ( -0.30623  0.3339 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.62865e-07 ( -2.8965e-08  2.8957e-08 ) ergs/cm2

Band function

Time interval is from    1.144 sec. to    2.144 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : 4.94887   ( -4.94887   -4.94887 )
beta        : -1.23281    ( -0.137535   0.135689 )
Epeak [keV] : 24.8741      ( -24.8741 5.25182 )
Norm@50keV   : 2706.92    ( -191.199   8.22307e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.59 using 59 PHA bins.
# Reduced chi-squared =          1.138 for     55 degrees of freedom 
# Null hypothesis probability =   2.249030e-01
 
Photon flux (15-150 keV)    in 1 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 20.2573  (-1.92476  2.19475)
R^2/D10^2   : 0.184382  (-0.0526216   0.0716433)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         111.40 using 59 PHA bins.
# Reduced chi-squared =         1.9544 for     57 degrees of freedom 
# Null hypothesis probability =   2.210764e-05
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.451e-08   2.315e-09
25- 50  7.289e-08   7.630e-09
50-150  2.221e-07   2.865e-08
15-150  3.095e-07   2.865e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (      )
Norm        : 17.3667       (-1.25914     1.25899)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          89.84 using 59 PHA bins.
# Reduced chi-squared =          1.576 for     57 degrees of freedom 
# Null hypothesis probability =   3.593150e-03
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.324e-08   3.675e-09
25- 50  8.317e-08   8.860e-09
50-150  1.824e-07   6.669e-08
15-150  3.088e-07   6.320e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 6.80546        (-1.40016      1.90092)
R1^2/D10^2  : 4.01649        (-2.25006      5.28526)
kT2 [keV]   : 31.1975        (-5.26604      9.37193)
R2^2/D10^2  : 3.97712E-02    (-0.0222445   0.0334037)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.77 using 59 PHA bins.
# Reduced chi-squared =          1.141 for     55 degrees of freedom 
# Null hypothesis probability =   2.203362e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.491e-08   1.440e-08
25- 50  7.461e-08   1.920e-08
50-150  2.561e-07   6.570e-08
15-150  3.656e-07   8.420e-08

Pre-slew spectrum (Pre-slew PHA with pre-slew DRM)

Power-law model

 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.46126     ( -0.0622463   0.0622684 )
Norm@50keV  : 1.57340E-02    ( -0.000517626   0.000517614 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.56 using 59 PHA bins.
# Reduced chi-squared =         0.7116 for     57 degrees of freedom 
# Null hypothesis probability =   9.510494e-01
 
Photon flux (15-150 keV)    in 20.12 sec: 1.94447 ( -0.070236  0.0705586 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.02313e-06 ( -1.05569e-07  1.05839e-07 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.40260     ( -0.243418   0.0873145 )
Epeak [keV] : 524.894      ( -577.82 -577.82 )
Norm@50keV  : 1.67245E-02    ( -0.00241488   0.00459747 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.47 using 59 PHA bins.
# Reduced chi-squared =         0.7226 for     56 degrees of freedom 
# Null hypothesis probability =   9.413538e-01
 
Photon flux (15-150 keV)    in 20.12 sec: 1.93636 ( -0.0764  0.07559 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.01426e-06 ( -1.13658e-07  1.10841e-07 ) ergs/cm2

Band function

 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.41458   ( 1.05127   1.05127 )
beta        : -8.67569    ( 9.22854   19.2259 )
Epeak [keV] : 698.661      ( -332.167 -630.78 )
Norm@50keV   : 1.65212E-02    ( -0.000548257   0.000896305 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          40.38 using 59 PHA bins.
# Reduced chi-squared =         0.7343 for     55 degrees of freedom 
# Null hypothesis probability =   9.299488e-01
 
Photon flux (15-150 keV)    in 20.12 sec: 1.93807 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 0 ( 0  0 ) ergs/cm2

S(25-50 keV) vs. S(50-100 keV) plot

S(25-50 keV)  = 9.55e-07
S(50-100 keV) = 1.32e-06

T90 vs. Hardness ratio plot

T90                                   = 38.9199999570847 sec.
Hardness ratio (energy fluence ratio) = 1.3822

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.31302
Count Ratio (50-100 keV) / (15-25 keV) = 1.11523

Mask shadow pattern

IMX = -7.458696005950929E-01, IMY = 4.542515287686889E-01

TIME vs. PHA plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

TIME vs. DetID plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

100 us light curve (15-350 keV)

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 1.024000

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:
-239.856000 -8.476000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6306  22.0134    0.5  36.2   60.8   9.9748  23.8    0.2	Crab                          
133.8005  -4.4349    3.4  40.8  -36.3   1.0027   3.3 ------	UNKNOWN

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

Time interval of the image:
-8.476000 11.644600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.4695  22.0938    3.6  36.3   61.0  -0.3897  -3.2   10.3	Crab                          
102.7810  -8.5080    2.3  47.2    8.1   0.5751   5.1 ------	UNKNOWN                       
175.7266  50.9772    0.3  41.1 -148.7   4.5866  45.4 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
69.844600 962.279700
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3741  35.3187    5.2  56.6 -164.2   4.1390   2.2    4.3	Her X-1                       
274.5661  63.2862    3.5  49.4  158.2   4.4995   3.3 ------	UNKNOWN                       
218.2631  61.0869    3.0  25.3  172.5   1.8261   3.9 ------	UNKNOWN                       
144.3834  23.7437    2.4  36.4   -4.2   3.0165   4.8 ------	UNKNOWN                       
195.0593  47.2887    3.2  13.2 -138.8   1.4935   3.6 ------	UNKNOWN                       
256.0619  32.8345    3.8  59.4 -163.2  12.5035   3.0 ------	UNKNOWN                       
155.0810   0.0771    3.5  53.8  -31.7   6.3342   3.3 ------	UNKNOWN

Plot creation:
Sun May 31 02:49:20 EDT 2015