batgrbproduct analysis for trigger=457553

batgrbproduct Analysis for Trigger=457553

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): Mon Jan 13 21:41:13 EST 2014
             Host Name: batevent1
   Current Working Dir: /local/data/batevent/batevent_reproc/trigger457553
======================================================================

  Trigger: 00457553      Segment: 000

  BAT Trigger Time: 332748559.04   [s; MET]
      Trigger Stop: 332748562.112   [s; MET]
               UTC: 2011-07-19T06:09:11.868540    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 24.5635253949573   Dec: 34.5721395739793  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.49
     Image Trigger?:     NO
     Rate S/N Ratio:     10.295630140987  [ if not an image trigger ]
     Image S/N Ratio:    7.49

  Flight Position:   [ source = BAT ]
    RA: 24.5635253949573   Dec: 34.5721395739793  [deg; J2000]

  Ground Position:   [ source = BAT pre-slew burst ]
    RA: 24.5780256402192   Dec: 34.5752863203935  [deg; J2000]  
        { 01h 38m 18.7s , +34d 34' 31.0" }
         +/- 1.55676516608891 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.561395910584576 [arcmin] (formal 1-sigma fit error)
    SNR: 16.1627011849492
 
  Angular difference between Flight and Ground position is 0.740830 arcmin
 
  Partial Coding Fraction: 0.3085938    [ including projection effects ]

  Duration
     T90: 41.227999985218 +/- 9.59850761999267
        Measured from: -1.02000004053116
                   to: 40.2079999446869     [s; relative to TRIGTIME]
     T50: 22.5159999728203 +/- 4.45701697537329
        Measured from: 4.97599995136261
                   to: 27.4919999241829     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 2.01599997282028     
                   to: 3.01599997282028     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -2.36400002241135     
                   to: 53.7159999608994     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.901103   1.190309   0.772925   0.146143
           0.086965   0.092097   0.084442   0.079513 [error]
 Peak      0.055737   0.027598   0.054838   0.009708
           0.012051   0.013296   0.012344   0.010860 [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 3.31e-07 5.25e-07 6.27e-07 1.46e-06 1.91e-06 2.94e-06   erg/cm2
              Error 4.64e-08 4.68e-08 8.24e-08 3.97e-07 1.94e-07 4.72e-07   erg/cm2
Peak flux Power-law 4.75e-01 4.24e-01 2.60e-01 2.42e-01 1.26e+00 1.40e+00   ph/cm2/s
              Error 2.15e-01 1.16e-01 1.09e-01 2.12e-01 3.40e-01 3.82e-01   ph/cm2/s
 
Fluence   Cutoff-PL 3.17e-07 5.46e-07 6.33e-07 8.38e-07 1.85e-06 2.33e-06   erg/cm2
              Error 5.26e-08 6.02e-08 8.75e-08 6.08e-07 2.18e-07 7.77e-07   erg/cm2
Peak flux Cutoff-PL 4.73e-01 4.23e-01 2.61e-01 2.43e-01 1.26e+00 1.40e+00   ph/cm2/s
              Error 2.16e-01 1.14e-01 9.54e-02 2.52e-01 3.38e-01 3.81e-01   ph/cm2/s
 
Fluence        Band 3.06e-07 5.57e-07 6.09e-07 1.25e-06 1.86e-06 2.73e-06   erg/cm2
              Error -------- -------- 8.69e-08 -------- 1.99e-07 --------   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    1.742    0.160    -      -           3.68e-03 3.58e-04   45.880 57
CPL   1.400    0.576      81.3  -29.5      5.62e-03 4.81e-03   44.940 56
 
 
=== 1-s peak spectral analysis ===
 
Model Ph_index Ph_90err Epeak  Epeak_90err Norm     Nomr_90err chi2   dof
PL    1.706    0.574    -      -           9.48e-03 2.98e-03   48.330 57
CPL   2.578    0.000     196.8    0.0      3.48e-03 0.00e+00   47.440 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: 23.424000 sec.
T50 in the 50-300 keV band: 14.848000 sec.

 
=== Table of the duration information ==
 
        Value   tstart    tstop
T100   56.080   -2.364   53.716
T90    41.228   -1.020   40.208
T50    22.516    4.976   27.492
Peak    1.000    2.016    3.016

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
   24.5780    34.5753   0.0119    43.5513   166.9462         2.8893371     16.163 TRIG_00457553                 
 
Foreground time interval of the image:
 -2.364  40.061 (delta_t =  42.425 [sec])
Background time interval of the image:
-239.040  -2.364 (delta_t = 236.676 [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 3.072000

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 3.072000

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 3.072000

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   -2.364 sec. to   53.716 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.74211     ( -0.157552   0.16169 )
Norm@50keV  : 3.67986E-03    ( -0.000360298   0.000355666 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.88 using 59 PHA bins.
# Reduced chi-squared =         0.8049 for     57 degrees of freedom 
# Null hypothesis probability =   8.541771e-01
 
Photon flux (15-150 keV)    in 56.08 sec: 0.496140 ( -0.044613  0.0446631 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.90511e-06 ( -1.9247e-07  1.94585e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -2.364 sec. to   53.716 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.40021     ( -0.685652   0.466372 )
Epeak [keV] : 81.3300      ( -22.3311 -81.3385 )
Norm@50keV  : 5.61964E-03    ( -0.00222579   0.00739574 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.94 using 59 PHA bins.
# Reduced chi-squared =         0.8024 for     56 degrees of freedom 
# Null hypothesis probability =   8.552891e-01
 
Photon flux (15-150 keV)    in 56.08 sec: 0.488829 ( -0.023278  0.045945 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.84908e-06 ( -2.18275e-07  2.17809e-07 ) ergs/cm2

Band function

Time interval is from   -2.364 sec. to   53.716 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : 1.97194   ( -1.9755   -1.9755 )
beta        : -1.87501    ( -0.268066   0.215226 )
Epeak [keV] : 28.0712      ( -28.0494 120.556 )
Norm@50keV   : 1.83150    ( -1.88007   223.852 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.61 using 59 PHA bins.
# Reduced chi-squared =         0.7929 for     55 degrees of freedom 
# Null hypothesis probability =   8.657589e-01
 
Photon flux (15-150 keV)    in 56.08 sec: 0.489246 (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.85963e-06 ( -1.85924e-06  -1.9849e-07 ) ergs/cm2

Single BB

 
Spectral model blackbody:
------------------------------------------------------------
Parameters  : value    Lower 90%  Upper 90%
kT [keV]    : 11.8838  (-1.31506  1.51758)
R^2/D10^2   : 0.122807  (-0.0440205   0.0671505)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          73.42 using 59 PHA bins.
# Reduced chi-squared =          1.288 for     57 degrees of freedom 
# Null hypothesis probability =   7.050990e-02
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  2.055e-07   3.513e-08
25- 50  6.394e-07   7.327e-08
50-150  5.394e-07   1.187e-07
15-150  1.384e-06   1.581e-07

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 113.935       (-33.1815      67.9389)
Norm        : 2.13641       (-0.246945     0.281136)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          44.98 using 59 PHA bins.
# Reduced chi-squared =         0.7891 for     57 degrees of freedom 
# Null hypothesis probability =   8.754938e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.126e-07   4.071e-08
25- 50  5.542e-07   6.222e-08
50-150  9.635e-07   3.775e-07
15-150  1.830e-06   4.212e-07

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 7.28613        (-1.64771      1.71127)
R1^2/D10^2  : 0.546358        (-0.274342      0.752146)
kT2 [keV]   : 27.4347        (-8.01342      19.7631)
R2^2/D10^2  : 4.09765E-03    (-0.00337497   0.0111508)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          43.60 using 59 PHA bins.
# Reduced chi-squared =         0.7927 for     55 degrees of freedom 
# Null hypothesis probability =   8.660341e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.004e-07   9.253e-08
25- 50  5.713e-07   1.747e-07
50-150  1.004e-06   5.036e-07
15-150  1.876e-06   6.581e-07

Peak spectrum fit

Power-law model

Time interval is from    2.016 sec. to    3.016 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.70554     ( -0.530289   0.617752 )
Norm@50keV  : 9.47512E-03    ( -0.00314478   0.00281424 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.33 using 59 PHA bins.
# Reduced chi-squared =         0.8478 for     57 degrees of freedom 
# Null hypothesis probability =   7.865216e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.26085 ( -0.339843  0.339893 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.76892e-08 ( -2.84951e-08  2.89883e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    2.016 sec. to    3.016 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 2.57801     (     )
Epeak [keV] : 196.829      (   )
Norm@50keV  : 3.48117E-03    (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.44 using 59 PHA bins.
# Reduced chi-squared =         0.8472 for     56 degrees of freedom 
# Null hypothesis probability =   7.851707e-01
 
Photon flux (15-150 keV)    in 1 sec: 1.25976 ( -0.336232  0.34013 ) ph/cm2/s
Energy fluence (15-150 keV)             : 8.7078e-08 ( -2.7731e-08  2.8788e-08 ) ergs/cm2

Band function

Time interval is from    2.016 sec. to    3.016 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.98951   ( 1.98951   1.98951 )
beta        : -1.70558    ( 1.70558   0.530249 )
Epeak [keV] : 3.67704      ( -3.66608 -3.66608 )
Norm@50keV   : 9.60872E-03    ( -0.00278183   1.62283 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          48.33 using 59 PHA bins.
# Reduced chi-squared =         0.8786 for     55 degrees of freedom 
# Null hypothesis probability =   7.256858e-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]    : 17.0935  (-7.55226  10.0528)
R^2/D10^2   : 8.31460E-02  (-0.0818969   0.533234)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.14 using 59 PHA bins.
# Reduced chi-squared =          1.002 for     57 degrees of freedom 
# Null hypothesis probability =   4.700326e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  4.940e-09   3.114e-09
25- 50  2.195e-08   1.319e-08
50-150  4.588e-08   2.919e-08
15-150  7.278e-08   4.674e-08

Thermal bremsstrahlung (OTTB)

 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 193.533       (-137.907      -191.45)
Norm        : 5.02227       (-1.3653     2.19718)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          49.27 using 59 PHA bins.
# Reduced chi-squared =         0.8643 for     57 degrees of freedom 
# Null hypothesis probability =   7.569920e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.255e-08   7.465e-09
25- 50  2.407e-08   1.433e-08
50-150  5.226e-08   3.122e-08
15-150  8.888e-08   5.235e-08

Double BB

 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 3.88697        (-1.58924      2.42705)
R1^2/D10^2  : 20.9873        (-18.7916      404.513)
kT2 [keV]   : 27.0891        (-10.1346      32.7189)
R2^2/D10^2  : 1.53762E-02    (-0.0137181   0.0401845)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          45.41 using 59 PHA bins.
# Reduced chi-squared =         0.8257 for     55 degrees of freedom 
# Null hypothesis probability =   8.182631e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.846e-08   1.133e-08
25- 50  1.658e-08   8.805e-09
50-150  5.931e-08   3.725e-08
15-150  9.435e-08   5.145e-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: 1.64361     ( -0.149884   0.152763 )
Norm@50keV  : 4.43345E-03    ( -0.00041345   0.000410208 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.20 using 59 PHA bins.
# Reduced chi-squared =         0.8281 for     57 degrees of freedom 
# Null hypothesis probability =   8.193125e-01
 
Photon flux (15-150 keV)    in 42.42 sec: 0.577686 ( -0.051679  0.0517492 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.75025e-06 ( -1.72586e-07  1.74159e-07 ) ergs/cm2

Cutoff power-law model

Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.873220     ( -0.743496   0.630046 )
Epeak [keV] : 69.8508      ( -15.5286 91.4759 )
Norm@50keV  : 1.12156E-02    ( -0.00587156   0.0159464 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          42.71 using 59 PHA bins.
# Reduced chi-squared =         0.7627 for     56 degrees of freedom 
# Null hypothesis probability =   9.044361e-01
 
Photon flux (15-150 keV)    in 42.42 sec: 0.559160 ( -0.053911  0.053885 ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.64994e-06 ( -1.90928e-07  1.9293e-07 ) ergs/cm2

Band function

 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -0.873102   ( -0.585854   0.577026 )
beta        : -10.0000    ( 10   0 )
Epeak [keV] : 69.8372      ( -14.0632 91.2968 )
Norm@50keV   : 1.12164E-02    ( -0.00587321   0.0159758 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          42.71 using 59 PHA bins.
# Reduced chi-squared =         0.7765 for     55 degrees of freedom 
# Null hypothesis probability =   8.864192e-01
 
Photon flux (15-150 keV)    in 42.42 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 1.66508e-06 ( 0  0 ) ergs/cm2

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

S(25-50 keV)  = 5.25e-07
S(50-100 keV) = 6.27e-07

T90 vs. Hardness ratio plot

T90                                   = 41.227999985218 sec.
Hardness ratio (energy fluence ratio) = 1.19429

Color vs. Color plot

Count Ratio  (25-50 keV) / (15-25 keV) = 1.32095
Count Ratio (50-100 keV) / (15-25 keV) = 0.857754

Mask shadow pattern

IMX = -9.261000766324821E-01, IMY = -2.147233277370557E-01

TIME vs. PHA plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000

TIME vs. DetID plot around the trigger time

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000

100 us light curve (15-350 keV)

Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 3.072000

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:
-239.040000 -2.364000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6306  22.0138    1.0  41.7 -111.1  10.0339  11.3    0.1	Crab                          
  7.0685  26.1634    2.3  49.6  144.6   5.3221   4.9 ------	UNKNOWN                       
 86.3766 -37.4145    2.0  49.0  -23.1   2.4962   5.7 ------	UNKNOWN                       
 96.0468 -20.4755    2.1  49.2  -48.2   5.5781   5.4 ------	UNKNOWN

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

Time interval of the image:
-2.364000 40.060600
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 83.6700  21.9992   66.6  41.7 -111.1  -0.0547  -0.2    2.2	Crab                          
 24.5780  34.5753    0.7  43.6  166.9   2.8894  16.2 ------	UNKNOWN                       
 53.0237  46.8355    2.6  49.4 -159.8   0.7841   4.5 ------	UNKNOWN

Post-slew image of 15-350 keV band

Time interval of the image:
100.460600 567.260580
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
 53.5166  44.8928    2.5  24.4 -104.2   1.7021   4.6 ------	UNKNOWN                       
 85.1341  70.2417    3.6  47.9 -137.0   2.9407   3.2 ------	UNKNOWN                       
109.4127  77.4811    4.9  55.3 -145.2   5.5330   2.3 ------	UNKNOWN

Plot creation:
Sat May 30 21:58:31 EDT 2015