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
  326.7949    -8.2502   0.0108    33.2124   166.0428         1.1948487     17.702 TRIG_00540964                 
 
Foreground time interval of the image:
 -2.160  15.757 (delta_t =  17.917 [sec])
Background time interval of the image:
-239.344  -2.160 (delta_t = 237.184 [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 
 
 8 ms binning
 From T100_start-3 s to T100_start+3 s
 
 2 ms binning
 From T100_start-1 s to T100_start+1 s
 
 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   -2.160 sec. to   44.716 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.41768     ( -0.0757698   0.0757357 )
Norm@50keV  : 6.35024E-03    ( -0.000261003   0.000260892 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.04 using 59 PHA bins.
# Reduced chi-squared =         0.6673 for     57 degrees of freedom 
# Null hypothesis probability =   9.749228e-01
 
Photon flux (15-150 keV)    in 46.88 sec: 0.776503 ( -0.033725  0.0337986 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.86637e-06 ( -1.28163e-07  1.28571e-07 ) ergs/cm2
 
Cutoff power-law model
 
Time interval is from   -2.160 sec. to   44.716 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.21116     ( -0.305762   0.239279 )
Epeak [keV] : 203.942      ( -90.8675 -203.942 )
Norm@50keV  : 7.95523E-03    ( -0.00175417   0.00304636 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          36.54 using 59 PHA bins.
# Reduced chi-squared =         0.6524 for     56 degrees of freedom 
# Null hypothesis probability =   9.795517e-01
 
Photon flux (15-150 keV)    in 46.88 sec: 0.766775 ( -0.036162  0.036204 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.82612e-06 ( -1.41512e-07  1.40846e-07 ) ergs/cm2
 
Band function
 
Time interval is from   -2.160 sec. to   44.716 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -0.906539   ( 0.90654   0.90654 )
beta        : -1.50221    ( 1.50224   0.132544 )
Epeak [keV] : 85.7029      ( -85.7787 -85.7787 )
Norm@50keV   : 1.23673E-02    ( -0.00619109   199.698 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          36.29 using 59 PHA bins.
# Reduced chi-squared =         0.6598 for     55 degrees of freedom 
# Null hypothesis probability =   9.758121e-01
 
Photon flux (15-150 keV)    in 46.88 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]    : 16.7899  (  )
R^2/D10^2   : 5.92428E-02  (   )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =         157.32 using 59 PHA bins.
# Reduced chi-squared =         2.7601 for     57 degrees of freedom 
# Null hypothesis probability =   2.483853e-11
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.600e-07   1.315e-08
25- 50  7.008e-07   4.172e-08
50-150  1.405e-06   1.081e-07
15-150  2.266e-06   1.125e-07
Thermal bremsstrahlung (OTTB)
 
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 200.000       (      )
Norm        : 3.21581       (-0.132163     0.132144)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          47.64 using 59 PHA bins.
# Reduced chi-squared =         0.8358 for     57 degrees of freedom 
# Null hypothesis probability =   8.068086e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.755e-07   1.725e-08
25- 50  7.223e-07   3.446e-08
50-150  1.584e-06   7.571e-08
15-150  2.682e-06   1.249e-07
Double BB
 
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 7.62491        (-1.17631      1.29174)
R1^2/D10^2  : 0.559027        (-0.218443      0.424428)
kT2 [keV]   : 29.1208        (-4.14943      6.49002)
R2^2/D10^2  : 7.30508E-03    (-0.00361998   0.00538684)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          38.97 using 59 PHA bins.
# Reduced chi-squared =         0.7085 for     55 degrees of freedom 
# Null hypothesis probability =   9.498492e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.115e-07   4.484e-08
25- 50  7.082e-07   8.345e-08
50-150  1.802e-06   2.782e-07
15-150  2.822e-06   3.500e-07
Peak spectrum fit
Power-law model
 
Time interval is from   27.908 sec. to   28.908 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.867029     ( -0.130419   0.126652 )
Norm@50keV  : 2.94757E-02    ( -0.00221729   0.00220381 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.73 using 59 PHA bins.
# Reduced chi-squared =          1.136 for     57 degrees of freedom 
# Null hypothesis probability =   2.248706e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.38299 ( -0.252647  0.25308 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.35118e-07 ( -2.60438e-08  2.61264e-08 ) ergs/cm2
 
Cutoff power-law model
 
Time interval is from   27.908 sec. to   28.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 0.626552     ( -0.530298   0.298732 )
Epeak [keV] : 336.866      ( -336.867 -336.867 )
Norm@50keV  : 3.75311E-02    ( -0.00969608   0.0249829 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.00 using 59 PHA bins.
# Reduced chi-squared =          1.143 for     56 degrees of freedom 
# Null hypothesis probability =   2.161362e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.35552 ( -0.25841  0.2586 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.32115e-07 ( -2.7255e-08  2.7025e-08 ) ergs/cm2
 
Band function
 
Time interval is from   27.908 sec. to   28.908 sec.
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : 5.00000   ( -5   -5 )
beta        : -0.867367    ( -0.126602   0.130537 )
Epeak [keV] : 16.2802      ( -16.2807 -16.2807 )
Norm@50keV   : 2.12205E+04    ( -1524.2   3.9946e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          64.72 using 59 PHA bins.
# Reduced chi-squared =          1.177 for     55 degrees of freedom 
# Null hypothesis probability =   1.736026e-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]    : 24.2887  (-2.44859  2.89461)
R^2/D10^2   : 9.21337E-02  (-0.0266888   0.0357245)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          90.83 using 59 PHA bins.
# Reduced chi-squared =          1.594 for     57 degrees of freedom 
# Null hypothesis probability =   2.919803e-03
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  9.586e-09   1.511e-09
25- 50  5.357e-08   7.385e-09
50-150  2.352e-07   2.690e-08
15-150  2.984e-07   2.705e-08
Thermal bremsstrahlung (OTTB)
 
 
 
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT [keV]    : 199.363       (      )
Norm        : 13.4569       (     )
------------------------------------------------------------
#Fit statistic : Chi-Squared =         141.20 using 59 PHA bins.
# Reduced chi-squared =         2.4772 for     57 degrees of freedom 
# Null hypothesis probability =   4.271256e-09
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  3.351e-08   3.095e-09
25- 50  6.446e-08   1.206e-08
50-150  1.414e-07   4.333e-08
15-150  2.393e-07   5.110e-08
Double BB
 
 
 
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters  : value         Lower 90%    Upper 90%
kT1 [keV]   : 10.5036        (-2.89722      3.61307)
R1^2/D10^2  : 0.665833        (-0.352034      0.971861)
kT2 [keV]   : 45.4732        (-12.854      53.1304)
R2^2/D10^2  : 1.22369E-02    (-0.0099696   0.0155384)
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.09 using 59 PHA bins.
# Reduced chi-squared =          1.129 for     55 degrees of freedom 
# Null hypothesis probability =   2.383340e-01
 
Energy  Fluence     90% Error
[keV]   [erg/cm2]   [erg/cm2]
15- 25  1.815e-08   6.598e-09
25- 50  6.139e-08   2.547e-08
50-150  2.569e-07   1.201e-07
15-150  3.364e-07   1.409e-07
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: 1.66169     ( -0.158362   0.162001 )
Norm@50keV  : 4.41575E-03    ( -0.000426495   0.000421924 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          57.90 using 59 PHA bins.
# Reduced chi-squared =          1.016 for     57 degrees of freedom 
# Null hypothesis probability =   4.420268e-01
 
Photon flux (15-150 keV)    in 17.92 sec: 0.578831 ( -0.0524536  0.0525162 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.351e-07 ( -7.50194e-08  7.58736e-08 ) ergs/cm2
 
Cutoff power-law model
 
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: 1.16801     ( -0.746067   0.565227 )
Epeak [keV] : 80.0313      ( -24.3454 -80.0313 )
Norm@50keV  : 8.02777E-03    ( -0.0038645   0.0115515 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.19 using 59 PHA bins.
# Reduced chi-squared =          1.003 for     56 degrees of freedom 
# Null hypothesis probability =   4.677876e-01
 
Photon flux (15-150 keV)    in 17.92 sec: 0.565720 ( -0.055242  0.055086 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.04984e-07 ( -8.47706e-08  8.47831e-08 ) ergs/cm2
 
Band function
 
 
Spectral model in the Band function:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
alpha       : -1.11570   ( 1.1105   4.42288 )
beta        : -2.15205    ( 2.14087   0.57374 )
Epeak [keV] : 75.1232      ( -73.8734 -73.8734 )
Norm@50keV   : 8.62580E-03    ( -0.00441944   0 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          56.16 using 59 PHA bins.
# Reduced chi-squared =          1.021 for     55 degrees of freedom 
# Null hypothesis probability =   4.313347e-01
 
Photon flux (15-150 keV)    in 17.92 sec:  (    ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.05372e-07 ( 0  0 ) ergs/cm2
 
 S(25-50 keV) vs. S(50-100 keV) plot 
 
S(25-50 keV)  = 6.80e-07
S(50-100 keV) = 1.02e-06
 T90 vs. Hardness ratio plot 
 
T90                                   = 42.9199999570847 sec.
Hardness ratio (energy fluence ratio) = 1.5
 Color vs. Color plot 
 
Count Ratio  (25-50 keV) / (15-25 keV) = 1.52105
Count Ratio (50-100 keV) / (15-25 keV) = 1.22927
 Mask shadow pattern 
 
IMX = -6.353624374023616E-01, IMY = -1.579095246858080E-01
 TIME vs. PHA plot around the trigger time 
 
 TIME vs. DetID plot around the trigger time 
 
 100 us light curve (15-350 keV)
 
 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:
-239.344000 -2.160000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.4610  35.4092   20.6  47.9   -2.8   0.2514   0.6    4.0	Her X-1                       
268.3308  -1.6084    2.8  31.3  -61.2   1.2494   4.1    9.6	SW J1753.5-0127               
274.0263 -14.0587    1.9  32.9  -86.9   2.3702   6.1    1.8	GX 17+2                       
284.8408 -24.9035   52.1  35.8 -112.9  -0.0908  -0.2   10.7	HT1900.1-2455                 
288.7829  10.9876    2.5   9.4  -27.9   0.9342   4.6    2.7	GRS 1915+105                  
299.8220  35.1841    4.4  26.7   49.6   0.7866   2.6   11.4	Cyg X-1                       
308.1548  40.9209    3.4  33.6   60.3   1.4925   3.4    2.8	Cyg X-3                       
326.1810  38.3171   52.8  39.1   82.3  -0.2168  -0.2    0.5	Cyg X-2                       
279.4946  47.6687    2.5  42.2   27.8   2.1630   4.5 ------	UNKNOWN                       
278.2818 -12.0343    2.9  28.5  -89.7   1.1558   4.0 ------	UNKNOWN                       
 Pre-slew background subtracted image of 15-350 keV band 
Time interval of the image:
-2.160000 15.756590
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
254.3659  35.4447    6.5  48.0   -2.8   0.1915   1.8    7.6	Her X-1                       
268.3823  -1.6521    4.3  31.3  -61.3  -0.1974  -2.7   12.0	SW J1753.5-0127               
273.8558 -14.0054    7.2  32.9  -86.6  -0.1486  -1.6    8.9	GX 17+2                       
285.2305 -24.9383    5.4  35.7 -113.5  -0.1858  -2.2   10.6	HT1900.1-2455                 
288.5967  10.9252    8.5   9.6  -28.5   0.0700   1.4   11.9	GRS 1915+105                  
299.8513  35.2060    0.0  26.7   49.7  -0.0891  -1.2   12.8	Cyg X-1                       
308.1793  40.8995    7.2  33.6   60.3  -0.1676  -1.6    4.5	Cyg X-3                       
326.2321  38.4861   10.0  39.2   82.2   0.2590   1.2   10.3	Cyg X-2                       
326.7949  -8.2502    0.7  33.2  166.0   1.1947  17.7 ------	UNKNOWN                       
297.8656   7.2424    2.3   1.3 -126.0   0.2390   5.0 ------	UNKNOWN                       
244.7339  30.2551    2.6  54.2  -12.3   0.6813   4.5 ------	UNKNOWN                       
 Post-slew image of 15-350 keV band 
Time interval of the image:
75.556610 602.746000
 
# RAcent  DECcent POSerr Theta    Phi  PeakCts   SNR AngSep     Name
#  [deg]    [deg]    ['] [deg]  [deg]                   [']
288.7195  10.8318    4.6  42.4  -42.3   1.3118   2.5    8.3	GRS 1915+105                  
299.6395  35.3343    6.0  50.5   -7.2   1.0768   1.9    8.3	Cyg X-1                       
307.9740  40.9690    4.7  52.2    3.7   1.8162   2.5    6.3	Cyg X-3                       
326.1184  38.4385    7.1  46.7   20.9   1.0293   1.6    7.4	Cyg X-2                       
  2.7347   8.9973    2.6  39.7   86.8   5.1234   4.5  564.0	UNKNOWN                       
357.5043 -53.0926    3.7  51.3  178.5   2.3513   3.2 ------	UNKNOWN                       
350.3231 -62.9743    3.1  57.3 -170.8   4.4363   3.8 ------	UNKNOWN                       
286.3449  31.5644    2.9  55.5  -20.5   3.5827   4.0 ------	UNKNOWN                       
286.2531  29.3955    2.0  54.2  -22.6   4.2652   5.8 ------	UNKNOWN                       
323.5723 -66.1676    4.5  58.0 -156.8   4.5889   2.6 ------	UNKNOWN                       
308.1939 -58.9939    3.1  52.7 -146.4   3.8260   3.7 ------	UNKNOWN                       
287.5147 -25.9357    5.4  41.3  -98.7   3.0250   2.1 ------	UNKNOWN                       
Plot creation:
Sat May 30 17:44:47 EDT 2015