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
336.2859 -2.2597 0.0077 6.2687 43.7789 1.7067683 25.015 TRIG_00238108
Foreground time interval of the image:
-8.796 30.021 (delta_t = 38.817 [sec])
Background time interval of the image:
-239.880 -8.796 (delta_t = 231.084 [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 2.048000
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 2.048000
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 2.048000
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 -8.796 sec. to 44.884 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64326 ( -0.116363 0.118208 )
Norm@50keV : 2.25567E-03 ( -0.000148295 0.000146779 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.03 using 59 PHA bins.
# Reduced chi-squared = 1.036 for 57 degrees of freedom
# Null hypothesis probability = 4.012400e-01
Photon flux (15-150 keV) in 53.68 sec: 0.293885 ( -0.0175294 0.0175503 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.1269e-06 ( -7.99875e-08 8.10632e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -8.796 sec. to 44.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.55621 ( -0.448175 0.195893 )
Epeak [keV] : 240.328 ( -240.328 -240.328 )
Norm@50keV : 2.50570E-03 ( -0.000645406 0.00173959 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.90 using 59 PHA bins.
# Reduced chi-squared = 1.052 for 56 degrees of freedom
# Null hypothesis probability = 3.697646e-01
Photon flux (15-150 keV) in 53.68 sec: 0.292203 ( -0.019143 0.009633 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11625e-06 ( -9.5647e-08 8.99569e-08 ) ergs/cm2
Band function
Time interval is from -8.796 sec. to 44.884 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.56181 ( 1.50463 1.50463 )
beta : -2.72219 ( 8.42448 6.89486 )
Epeak [keV] : 252.022 ( -150.055 -252.078 )
Norm@50keV : 2.48981E-03 ( -0.000375564 0.00212981 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.90 using 59 PHA bins.
# Reduced chi-squared = 1.071 for 55 degrees of freedom
# Null hypothesis probability = 3.347063e-01
Photon flux (15-150 keV) in 53.68 sec: 0.291637 ( ) 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] : 13.1453 ( )
R^2/D10^2 : 4.94841E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 128.34 using 59 PHA bins.
# Reduced chi-squared = 2.2515 for 57 degrees of freedom
# Null hypothesis probability = 2.040942e-07
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 9.733e-08 1.055e-08
25- 50 3.392e-07 2.504e-08
50-150 3.730e-07 5.279e-08
15-150 8.096e-07 5.636e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 160.681 (-47.4788 -159.736)
Norm : 1.19352 (-0.0766298 0.0964852)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 60.14 using 59 PHA bins.
# Reduced chi-squared = 1.055 for 57 degrees of freedom
# Null hypothesis probability = 3.626383e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.635e-07 1.337e-08
25- 50 3.061e-07 5.556e-08
50-150 6.211e-07 2.561e-07
15-150 1.091e-06 2.738e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.53364 (-1.03868 1.22548)
R1^2/D10^2 : 0.756205 (-0.393842 0.995228)
kT2 [keV] : 22.1477 (-3.42562 5.18775)
R2^2/D10^2 : 6.47236E-03 (-0.00342704 0.005549)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.70 using 59 PHA bins.
# Reduced chi-squared = 1.067 for 55 degrees of freedom
# Null hypothesis probability = 3.415618e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.771e-07 4.694e-08
25- 50 2.881e-07 5.604e-08
50-150 6.197e-07 1.430e-07
15-150 1.085e-06 2.300e-07
Peak spectrum fit
Power-law model
Time interval is from 2.116 sec. to 3.116 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.03985 ( -0.516577 0.59858 )
Norm@50keV : 3.08211E-03 ( -0.00121727 0.00117054 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.97 using 59 PHA bins.
# Reduced chi-squared = 1.052 for 57 degrees of freedom
# Null hypothesis probability = 3.686809e-01
Photon flux (15-150 keV) in 1 sec: 0.470991 ( -0.117806 0.118058 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.84917e-08 ( -9.65139e-09 1.08859e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.116 sec. to 3.116 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.08630 ( )
Epeak [keV] : 38.0733 ( )
Norm@50keV : 2.68307E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 59.79 using 59 PHA bins.
# Reduced chi-squared = 1.068 for 56 degrees of freedom
# Null hypothesis probability = 3.397716e-01
Photon flux (15-150 keV) in 1 sec: 0.470024 ( -0.11678 0.115974 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.83164e-08 ( -1.15668e-08 1.08852e-08 ) ergs/cm2
Band function
Time interval is from 2.116 sec. to 3.116 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.97722 ( -4.97722 -4.97722 )
beta : -2.37854 ( -1.29647 0.697384 )
Epeak [keV] : 21.3488 ( -21.3488 5.26383 )
Norm@50keV : 1564.36 ( -377.687 5.74259e+06 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 58.47 using 59 PHA bins.
# Reduced chi-squared = 1.063 for 55 degrees of freedom
# Null hypothesis probability = 3.492660e-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] : 6.63947 (-1.68905 2.38138)
R^2/D10^2 : 1.06070 (-1.06018 2.50327)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 63.21 using 59 PHA bins.
# Reduced chi-squared = 1.109 for 57 degrees of freedom
# Null hypothesis probability = 2.664022e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.087e-09 4.141e-09
25- 50 8.740e-09 5.400e-09
50-150 1.192e-09 9.931e-10
15-150 1.702e-08 1.009e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 48.7794 (-28.1467 -48.8766)
Norm : 2.66083 (-1.02962 2.32857)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 61.12 using 59 PHA bins.
# Reduced chi-squared = 1.072 for 57 degrees of freedom
# Null hypothesis probability = 3.303002e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 6.468e-09 2.897e-09
25- 50 9.208e-09 4.382e-09
50-150 8.732e-09 6.596e-09
15-150 2.441e-08 1.204e-08
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 5.68747 (-1.54937 1.99563)
R1^2/D10^2 : 1.82903 (-1.29905 5.17406)
kT2 [keV] : 81.2615 (-60.1119 -81.2331)
R2^2/D10^2 : 3.24945E-04 (-0.000291193 0.00836358)
------------------------------------------------------------
#Fit statistic : Chi-Squared = 55.97 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 55 degrees of freedom
# Null hypothesis probability = 4.381714e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.407e-09 4.425e-09
25- 50 7.655e-09 4.364e-09
50-150 2.225e-08 1.653e-08
15-150 3.731e-08 1.951e-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: 1.66135 ( -0.115499 0.117352 )
Norm@50keV : 2.66636E-03 ( -0.000176123 0.00017429 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.45 using 59 PHA bins.
# Reduced chi-squared = 1.008 for 57 degrees of freedom
# Null hypothesis probability = 4.584252e-01
Photon flux (15-150 keV) in 38.82 sec: 0.349476 ( -0.0207604 0.0207829 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.61599e-07 ( -6.81376e-08 6.90651e-08 ) ergs/cm2
Cutoff power-law model
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.53870 ( -0.453943 0.228506 )
Epeak [keV] : 174.649 ( -174.649 -174.649 )
Norm@50keV : 3.09740E-03 ( )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.20 using 59 PHA bins.
# Reduced chi-squared = 1.021 for 56 degrees of freedom
# Null hypothesis probability = 4.302716e-01
Photon flux (15-150 keV) in 38.82 sec: 0.346726 ( -0.02265 0.022401 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.48155e-07 ( -8.24692e-08 7.92316e-08 ) ergs/cm2
Band function
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.52057 ( -0.170893 0.239006 )
beta : -9.37167 ( 9.37167 19.3717 )
Epeak [keV] : 161.326 ( -76.227 -161.492 )
Norm@50keV : 3.15930E-03 ( -0.00065104 0.00107651 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 57.21 using 59 PHA bins.
# Reduced chi-squared = 1.040 for 55 degrees of freedom
# Null hypothesis probability = 3.931582e-01
Photon flux (15-150 keV) in 38.82 sec: 0.345092 ( ) 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) = 2.98e-07
S(50-100 keV) = 3.81e-07
T90 vs. Hardness ratio plot
T90 = 44.5080000162125 sec.
Hardness ratio (energy fluence ratio) = 1.27852
Color vs. Color plot
Count Ratio (25-50 keV) / (15-25 keV) = 1.12167
Count Ratio (50-100 keV) / (15-25 keV) = 0.778729
Mask shadow pattern
IMX = 7.931218979124242E-02, IMY = -7.600160850657510E-02
TIME vs. PHA plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
TIME vs. DetID plot around the trigger time
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
100 us light curve (15-350 keV)
Blue+Cyan dotted lines: Time interval of the scaled map
From 0.000000 to 2.048000
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:
-239.880000 -8.796000
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.7924 10.9630 2.6 49.2 -41.9 3.1010 4.4 1.1 GRS 1915+105
299.5895 35.2113 0.9 54.4 -9.1 8.1955 13.2 0.6 Cyg X-1
308.1119 40.9785 39.7 54.8 1.7 -0.2217 -0.3 1.6 Cyg X-3
326.1511 38.1592 8.2 47.0 17.0 0.6723 1.4 9.8 Cyg X-2
348.4092 32.6354 3.1 43.0 43.3 2.2411 3.7 ------ UNKNOWN
331.5519 32.8448 2.2 41.2 22.2 1.8471 5.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image:
-8.796000 30.020610
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
288.9064 10.9148 4.6 49.1 -41.9 0.6534 2.5 6.6 GRS 1915+105
299.5875 35.2290 6.3 54.4 -9.1 -0.4077 -1.8 1.6 Cyg X-1
308.1993 40.8891 7.5 54.7 1.7 0.4604 1.5 5.5 Cyg X-3
326.1049 38.2106 87.6 47.1 17.0 -0.0230 -0.1 7.4 Cyg X-2
23.2762 -25.4947 2.1 49.6 142.5 1.7504 5.4 ------ UNKNOWN
346.6464 38.5804 2.1 48.2 38.7 1.7002 5.6 ------ UNKNOWN
346.2906 19.8722 2.2 30.5 48.4 0.5496 5.4 ------ UNKNOWN
355.6217 -20.2886 2.1 23.8 148.5 0.4257 5.5 ------ UNKNOWN
336.2859 -2.2597 0.5 6.3 43.8 1.7067 25.0 ------ UNKNOWN
309.5150 17.1473 2.2 35.3 -18.2 0.4745 5.1 ------ UNKNOWN
288.3166 1.7399 2.2 47.0 -54.0 1.5226 5.2 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image:
57.620600 962.225600
# RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name
# [deg] [deg] ['] [deg] [deg] [']
299.5808 35.2021 0.5 50.8 -20.0 33.2653 25.7 0.5 Cyg X-1
308.1358 40.8499 30.1 50.2 -8.6 0.4581 0.4 6.3 Cyg X-3
326.2656 38.3990 6.3 41.7 7.2 1.4486 1.8 6.4 Cyg X-2
9.2223 21.5859 3.2 40.1 70.8 7.3686 3.5 ------ UNKNOWN
4.3493 32.6750 3.0 43.9 53.9 7.7660 3.9 ------ UNKNOWN
0.1028 5.1857 3.0 24.9 91.7 2.3791 3.9 311.2 UNKNOWN
341.4074 41.6467 2.9 44.1 24.6 3.9731 4.0 ------ UNKNOWN
356.4099 -57.1507 4.2 57.2 -173.7 7.4126 2.8 ------ UNKNOWN
313.9136 -54.4170 5.1 55.3 -145.3 8.1456 2.3 ------ UNKNOWN
Plot creation:
Sun May 31 11:31:51 EDT 2015