GRB180418A

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: Fri May 11 17:59:21 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger826428
======================================================================

  Trigger: 00826428      Segment: 000

  BAT Trigger Time: 545726666.816   [s; MET]
      Trigger Stop: 545726667.264   [s; MET]
               UTC: 2018-04-18T06:44:06.012000    [includes UTCF correction] 
       Where From?: (*SHORT BURST*) Expanded to TRIGTIME - 64 ms to TRIGTIME + 320 ms

  BAT 
    RA: 170.112382201695   Dec: 24.9562917733818  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    8.81
     Image Trigger?:     NO
     Rate S/N Ratio:     22.8473193175917  [ if not an image trigger ]
     Image S/N Ratio:    8.81

  Analysis Position:   [ source = BAT ]
    RA: 170.112382201695   Dec: 24.9562917733818  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 170.128590124768   Dec: 24.9270362960537  [deg; J2000]  
        { 11h 20m 30.9s , +24d 55' 37.3" }
         +/- 1.3625519161545 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.508540245299671 [arcmin] (formal 1-sigma fit error)
    SNR: 19.5517411474932
 
  Angular difference between the analysis and refined position is 1.964361 arcmin
 
  Partial Coding Fraction: 1    [ including projection effects ]

  Duration
     T90: 4.40799999237061 +/- 2.49110413778446
        Measured from: 0.279999971389771
                   to: 4.68799996376038     [s; relative to TRIGTIME]
     T50: 0.787999987602234 +/- 0.188509894903112
        Measured from: 0.480000019073486
                   to: 1.26800000667572     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 0.236000061035156     
                   to: 1.23600006103516     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: 0.0959999561309814     
                   to: 7.16799998283386     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.122150   0.214889   0.163279   0.049147
           0.014874   0.015816   0.014133   0.011788 [error]
 Peak      0.097779   0.153141   0.101117   0.041370
           0.006913   0.007981   0.007038   0.005314 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100    7.072    0.096    7.168
T90     4.408    0.280    4.688
T50     0.788    0.480    1.268
Peak    1.000    0.236    1.236
 
 
====== 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: CPL)
 
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      -1.358    -0.143      0.142       -           -               -         4.95e-03     -4.28e-04          4.27e-04      62.170   57
CPL     -0.343    -0.676      0.802       79.685     -16.808        61.912      1.64e-02     -8.92e-03          2.53e-02      55.160   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      -1.408     -0.107     0.107       -           -               -         2.48e-02     -1.53e-03          1.53e-03      60.840   57
CPL     -1.343     -0.165     0.370      506.463    -506.463      -506.463      2.68e-02     -3.41e-03          1.38e-02      60.890   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   3.91e-08  7.85e-08  1.22e-07  4.21e-07  3.41e-07  6.61e-07   erg/cm2
      90%_error_low -5.55e-09 -7.09e-09 -1.34e-08 -9.00e-08 -3.29e-08 -1.02e-07   erg/cm2
      90%_error_hi   5.76e-09  7.05e-09  1.33e-08  1.05e-07  3.33e-08  1.14e-07   erg/cm2
Peak flux       PL   9.34e-01  9.93e-01  7.48e-01  9.16e-01  3.02e+00  3.59e+00   ph/cm2/s
      90%_error_low -9.92e-02 -6.55e-02 -5.81e-02 -1.40e-01 -1.86e-01 -2.25e-01   ph/cm2/s
      90%_error_hi   1.02e-01  6.50e-02  5.77e-02  1.54e-01  1.86e-01  2.27e-01   ph/cm2/s
 
Fluence        CPL   3.34e-08  8.72e-08  1.28e-07  1.12e-07  3.13e-07  3.60e-07   erg/cm2
      90%_error_low -6.67e-09 -9.24e-09 -1.54e-08 -5.93e-08 -3.75e-08 -6.89e-08   erg/cm2
      90%_error_hi   6.82e-09  9.58e-09  1.54e-08  1.40e-07  3.82e-08  1.40e-07   erg/cm2
Peak flux      CPL   9.33e-01  9.95e-01  7.49e-01  9.08e-01  3.02e+00  3.57e+00   ph/cm2/s
      90%_error_low -1.17e-01 -6.70e-02 -5.94e-02 -3.69e-01 -1.92e-01 -4.12e-01   ph/cm2/s
      90%_error_hi   8.56e-02  7.72e-02  6.44e-02  9.54e-02  1.88e-01  2.40e-01   ph/cm2/s
 
======================================================================

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
  170.1286    24.9270   0.0098    14.4701   167.3957         0.5726498     19.552 TRIG_00826428                 
 
Foreground time interval of the image:
  0.096   7.168 (delta_t =   7.072 [sec])
Background time interval of the image:
-238.816   0.096 (delta_t = 238.912 [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

Bokeh Plot

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    0.096 sec. to    7.168 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.3579     ( -0.142761   0.142475 )
Norm@50keV  : 4.95128E-03    ( -0.000428222   0.000427196 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          62.17 using 59 PHA bins.
# Reduced chi-squared =          1.091 for     57 degrees of freedom 
# Null hypothesis probability =   2.972892e-01
 
Photon flux (15-150 keV)    in 7.072 sec: 0.597474 ( -0.05141  0.051453 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.41431e-07 ( -3.29397e-08  3.33028e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.096 sec. to    7.168 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.343053     ( -0.676202   0.802183 )
Epeak [keV] : 79.6850      ( -16.8081 61.9121 )
Norm@50keV  : 1.64226E-02    ( -0.00891734   0.0252565 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          55.16 using 59 PHA bins.
# Reduced chi-squared =         0.9850 for     56 degrees of freedom 
# Null hypothesis probability =   5.065749e-01
 
Photon flux (15-150 keV)    in 7.072 sec: 0.572963 ( -0.054105  0.053972 ) ph/cm2/s
Energy fluence (15-150 keV)             : 3.12912e-07 ( -3.74623e-08  3.82458e-08 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    0.236 sec. to    1.236 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.4081     ( -0.107329   0.106841 )
Norm@50keV  : 2.47880E-02    ( -0.0015341   0.00152981 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.84 using 59 PHA bins.
# Reduced chi-squared =          1.067 for     57 degrees of freedom 
# Null hypothesis probability =   3.395533e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.02436 ( -0.18601  0.18618 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.39155e-07 ( -1.65679e-08  1.668e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    0.236 sec. to    1.236 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.40509     ( -0.161177   0.374541 )
Epeak [keV] : 9996.82      ( -9996.71 -9996.71 )
Norm@50keV  : 2.48765E-02    ( -0.00152908   0.0156944 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          60.84 using 59 PHA bins.
# Reduced chi-squared =          1.086 for     56 degrees of freedom 
# Null hypothesis probability =   3.060837e-01
 
Photon flux (15-150 keV)    in 1 sec: 3.02263 ( -0.19223  0.18788 ) ph/cm2/s
Energy fluence (15-150 keV)             : 2.38864e-07 ( -1.82668e-08  1.69534e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 4.408 sec.
Hardness ratio (energy fluence ratio) = 1.46656105156

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

S(15-50 keV)  = 1.2060757e-07
S(50-150 keV) = 1.923031e-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.

 IMX = -2.518425959351169E-01,

Spacecraft aspect plot

Bright

Pre-burst

 Time interval of the image: -238.816000 0.096000

# RAcent #  [deg] 254.5044  35.4151 191.0885  16.4902 134.2644   0.3504 127.7262   8.2839 124.8780  26.4324 171.7109  72.7484 133.8516  58.5737 122.3030  44.2015

Pre-slew

 Time interval of the image: 0.096000 7.168000

# RAcent #  [deg] 254.3737  35.2865 198.9368  17.6143 247.2324  22.8140 170.1286  24.9271 153.0066  35.3017

Post-slew

 Time interval of the image: 272.084600 963.276800

# RAcent #  [deg] 244.9705 -15.6366 254.4896  35.3542 256.0230 -37.8131 256.6137 -36.3063 263.0217 -24.6314 264.5628 -44.5975 268.2156  -1.3128 270.1184 -25.0662 270.2307 -25.6985 274.0641 -13.8812 275.9108 -30.3773 285.0311 -24.8137 288.8058  10.9616 262.8635 -33.8072 275.0902   7.1830 297.4221 -47.3215 319.5309 -45.8613 320.4426 -35.8338 305.3106  16.1417

Mask shadow pattern

IMY = -5.631317706837238E-02 source in the pre-burst/pre-slew/post-slew images image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 7.1 57.2 -5.0 -1.4757 -1.6 4.9 Her X-1 3.0 18.0 85.3 0.7999 3.9 ------ UNKNOWN 3.3 56.8 173.9 4.6709 3.5 ------ UNKNOWN 2.8 57.2 -173.8 5.0046 4.2 ------ UNKNOWN 2.6 50.9 -152.5 2.7407 4.5 ------ UNKNOWN 3.3 40.0 -76.8 3.0193 3.5 ------ UNKNOWN 2.9 41.6 -108.3 3.4717 4.1 ------ UNKNOWN 3.0 48.1 -129.2 3.9731 3.9 ------ UNKNOWN background subtracted image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 14.0 57.1 -4.9 -0.1122 -0.8 5.3 Her X-1 2.3 20.7 63.7 0.1661 5.1 ------ UNKNOWN 2.2 56.2 11.8 0.9273 5.3 ------ UNKNOWN 0.6 14.5 167.4 0.5725 19.5 ------ UNKNOWN 2.3 25.4 -147.9 0.1572 4.9 ------ UNKNOWN image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 0.7 25.0 95.8 22.5001 16.2 0.6 Sco X-1 49.3 55.6 167.9 -1.2725 -0.2 1.7 Her X-1 2.6 23.7 34.7 4.7663 4.4 2.5 4U 1700-377 17.2 22.2 36.1 0.6817 0.7 11.1 GX 349+2 7.1 9.9 51.2 1.4921 1.6 6.9 GX 1+4 0.0 27.1 14.3 2.5790 2.4 11.7 4U 1735-44 0.0 17.0 174.7 1.4788 1.5 12.4 SW J1753.5-0127 8.2 7.1 10.6 1.2632 1.4 9.0 GX 5-1 2.9 7.7 9.3 3.9476 4.3 4.7 GRS 1758-258 3.5 5.1 -140.0 3.1739 3.3 9.9 GX 17+2 4.0 13.1 -14.8 2.5744 2.8 1.0 H1820-303 22.6 14.7 -56.0 -0.5101 -0.5 6.4 HT1900.1-2455 1.9 33.9 -143.2 8.2858 6.2 1.1 GRS 1915+105 2.4 17.4 27.4 4.4263 4.9 6.5 GX 354-0 0.1 25.6 -166.3 96.4887 93.5 ------ UNKNOWN 2.3 36.4 -26.4 6.3187 5.1 ------ UNKNOWN 3.1 48.6 -39.8 14.0591 3.8 ------ UNKNOWN 2.4 47.0 -53.2 23.4153 4.8 ------ UNKNOWN 3.1 48.1 -129.1 18.7146 3.7 ------ UNKNOWN

Analysis Summary

Notes:

Image

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

Light Curves

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:

Time averaged spectrum fit using the average DRM

Power-law model

Cutoff power-law model

1-s peak spectrum fit

Power-law model

Cutoff power-law model

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

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

IMX = -2.518425959351169E-01,

Spacecraft aspect plot

Bright

Pre-burst Time interval of the image: -238.816000 0.096000 # RAcent # [deg] 254.5044 35.4151 191.0885 16.4902 134.2644 0.3504 127.7262 8.2839 124.8780 26.4324 171.7109 72.7484 133.8516 58.5737 122.3030 44.2015

Pre-slew Time interval of the image: 0.096000 7.168000 # RAcent # [deg] 254.3737 35.2865 198.9368 17.6143 247.2324 22.8140 170.1286 24.9271 153.0066 35.3017

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

Pre-burst
Time interval of the image: -238.816000 0.096000 # RAcent # [deg] 254.5044 35.4151 191.0885 16.4902 134.2644 0.3504 127.7262 8.2839 124.8780 26.4324 171.7109 72.7484 133.8516 58.5737 122.3030 44.2015

Pre-slew
Time interval of the image: 0.096000 7.168000 # RAcent # [deg] 254.3737 35.2865 198.9368 17.6143 247.2324 22.8140 170.1286 24.9271 153.0066 35.3017