GRB180222A

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: Thu Apr  5 17:43:07 EDT 2018
             Host Name: bat1
   Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger811235
======================================================================

  Trigger: 00811235      Segment: 000

  BAT Trigger Time: 540997824.064   [s; MET]
      Trigger Stop: 540997826.112   [s; MET]
               UTC: 2018-02-22T13:10:03.545680    [includes UTCF correction] 
       Where From?: TDRSS position message

  BAT 
    RA: 256.571083609051   Dec: -36.8026566389767  [deg; J2000]

     Catalogged Source?: NO
     Point Source?:      YES
     GRB Indicated?:     YES    [ by BAT flight software ]
     Image S/N Ratio:    7.78
     Image Trigger?:     NO
     Rate S/N Ratio:     14.9666295470958  [ if not an image trigger ]
     Image S/N Ratio:    7.78

  Analysis Position:   [ source = BAT ]
    RA: 256.571083609051   Dec: -36.8026566389767  [deg; J2000]

  Refined Position:   [ source = BAT pre-slew burst ]
    RA: 256.531301202391   Dec: -36.8209816557979  [deg; J2000]  
        { 17h 06m 07.5s , -36d 49' 15.5" }
         +/- 1.41587105456752 [arcmin] (estimated 90% radius based on SNR)
         +/- 0.653255780877618 [arcmin] (formal 1-sigma fit error)
    SNR: 18.5084577702148
 
  Angular difference between the analysis and refined position is 2.204733 arcmin
 
  Partial Coding Fraction: 0.984375    [ including projection effects ]

  Duration
     T90: 42.3039999008179 +/- 12.74307334245
        Measured from: 0.424000024795532
                   to: 42.7279999256134     [s; relative to TRIGTIME]
     T50: 17.2799998521805 +/- 6.94724346365421
        Measured from: 4.00800001621246
                   to: 21.2879998683929     [s; relative to TRIGTIME]



  Fluence
     Peak Flux  (peak 1 second)
        Measured from: 3.28400003910065     
                   to: 4.28400003910065     [s; relative to TRIGTIME]
     Total Fluence        
        Measured from: -0.472000002861023     
                   to: 55.3359999656677     [s; relative to TRIGTIME]
     
             Band 1     Band 2     Band 3     Band 4
              15-25      25-50     50-100    100-350     keV
 Total     0.431479   0.540839   0.436219   0.099931
           0.055230   0.050066   0.043051   0.037602 [error]
 Peak      0.016735   0.035278   0.038263   0.012534
           0.007585   0.007236   0.006357   0.005235 [error]

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

======================================================================
 
 
====== Table of the duration information =============================
 
        Value   tstart    tstop
T100   55.808   -0.472   55.336
T90    42.304    0.424   42.728
T50    17.280    4.008   21.288
Peak    1.000    3.284    4.284
 
 
====== 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: 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      -1.492    -0.184      0.182       -           -               -         1.71e-03     -1.71e-04          1.69e-04      53.030   57
CPL     -1.404    -0.774      0.614      339.521    -339.521      -339.521      1.89e-03     -1.02e-03          1.81e-03      53.080   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      -0.887     -0.383     0.421       -           -               -         6.27e-03     -1.41e-03          1.36e-03      58.400   57
CPL     -0.804      0.804     1.716      869.705    -869.705      -869.705      6.79e-03     -1.80e-03          2.41e-02      58.390   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   1.21e-07  2.23e-07  3.17e-07  9.51e-07  9.05e-07  1.61e-06   erg/cm2
      90%_error_low -2.06e-08 -2.30e-08 -4.22e-08 -2.52e-07 -9.98e-08 -2.86e-07   erg/cm2
      90%_error_hi   2.16e-08  2.28e-08  4.20e-08  3.10e-07  1.01e-07  3.35e-07   erg/cm2
Peak flux       PL   1.44e-01  2.09e-01  2.26e-01  4.56e-01  7.19e-01  1.04e+00   ph/cm2/s
      90%_error_low -6.36e-02 -6.23e-02 -4.87e-02 -1.89e-01 -1.57e-01 -2.29e-01   ph/cm2/s
      90%_error_hi   7.76e-02  6.08e-02  4.81e-02  2.72e-01  1.59e-01  2.53e-01   ph/cm2/s
 
Fluence        CPL   1.21e-07  2.23e-07  3.17e-07  9.46e-07  9.05e-07  1.60e-06   erg/cm2
      90%_error_low -2.13e-08 -2.28e-08 -3.35e-08 -5.98e-07 -1.12e-07 -6.04e-07   erg/cm2
      90%_error_hi   1.67e-08  2.68e-08  4.42e-08  1.78e-07  1.00e-07  1.86e-07   erg/cm2
Peak flux      CPL   1.40e-01  2.09e-01  2.28e-01  4.19e-01  7.16e-01  9.97e-01   ph/cm2/s
      90%_error_low -8.15e-02 -6.35e-02 -5.08e-02 -4.19e-01 -1.64e-01 -3.67e-01   ph/cm2/s
      90%_error_hi   6.16e-02  6.34e-02  6.15e-02  3.98e-01  1.61e-01  2.80e-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
  256.5313   -36.8210   0.0104    11.4176    40.0338         1.2904210     18.508 TRIG_00811235                 
 
Foreground time interval of the image:
 -0.472  28.837 (delta_t =  29.309 [sec])
Background time interval of the image:
-239.064  -0.472 (delta_t = 238.592 [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   -0.472 sec. to   55.336 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.49187     ( -0.183722   0.182338 )
Norm@50keV  : 1.70713E-03    ( -0.000170581   0.000169482 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.03 using 59 PHA bins.
# Reduced chi-squared =         0.9304 for     57 degrees of freedom 
# Null hypothesis probability =   6.245824e-01
 
Photon flux (15-150 keV)    in 55.81 sec: 0.212659 ( -0.021091  0.021158 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.05154e-07 ( -9.98463e-08  1.0111e-07 ) ergs/cm2

Cutoff power-law model

Time interval is from   -0.472 sec. to   55.336 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -1.48929     ( -0.766427   0.621 )
Epeak [keV] : 9995.16      ( -9995.11 -9995.11 )
Norm@50keV  : 1.71231E-03    ( -0.000845794   0.00199256 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          53.03 using 59 PHA bins.
# Reduced chi-squared =         0.9470 for     56 degrees of freedom 
# Null hypothesis probability =   5.878473e-01
 
Photon flux (15-150 keV)    in 55.81 sec: 0.212629 ( -0.022434  0.021002 ) ph/cm2/s
Energy fluence (15-150 keV)             : 9.04926e-07 ( -1.12275e-07  1.00181e-07 ) ergs/cm2

1-s peak spectrum fit

Power-law model

Time interval is from    3.284 sec. to    4.284 sec.
 
Spectral model in power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.886958     ( -0.382891   0.420701 )
Norm@50keV  : 6.26880E-03    ( -0.00140522   0.00136205 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.40 using 59 PHA bins.
# Reduced chi-squared =          1.025 for     57 degrees of freedom 
# Null hypothesis probability =   4.238113e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.719457 ( -0.157104  0.159 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.07196e-08 ( -1.54037e-08  1.55306e-08 ) ergs/cm2

Cutoff power-law model

Time interval is from    3.284 sec. to    4.284 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters  : value       lower 90%   higher 90%
Photon index: -0.803562     ( 0.803563   1.71569 )
Epeak [keV] : 869.705      ( -869.713 -869.713 )
Norm@50keV  : 6.79333E-03    ( -0.00179619   0.0240885 )
------------------------------------------------------------
#Fit statistic : Chi-Squared =          58.39 using 59 PHA bins.
# Reduced chi-squared =          1.043 for     56 degrees of freedom 
# Null hypothesis probability =   3.877625e-01
 
Photon flux (15-150 keV)    in 1 sec: 0.716452 ( -0.163927  0.16142 ) ph/cm2/s
Energy fluence (15-150 keV)             : 7.04579e-08 ( -1.62927e-08  1.56831e-08 ) ergs/cm2

Time-resolved spectra

Distribution

T90 vs. Hardness ratio plot

T90                                   = 42.304 sec.
Hardness ratio (energy fluence ratio) = 1.42226277896

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

S(15-50 keV)  = 3.436843e-07
S(50-150 keV) = 5.614692e-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 = 1.546298711303626E-01,

Spacecraft aspect plot

Bright

Pre-burst

 Time interval of the image: -239.064000 -0.472000

# RAcent #  [deg] 244.9727 -15.6428 255.9071 -37.8048 256.6085 -36.4946 262.8288 -24.8806 264.6187 -44.5692 268.2441  -1.2949 270.2840 -25.0890 270.4658 -25.8254 273.8699 -14.1070 275.8734 -30.3614 285.1509 -25.0571 288.7816  10.9468 263.0478 -33.8383 275.6268  19.2787 280.9067  -7.9776 288.1877  -1.1390 290.6053   3.9958

Pre-slew

 Time interval of the image: -0.472000 28.836590

# RAcent #  [deg] 245.1653 -15.5300 255.7934 -37.8623 256.5262 -36.5866 262.9251 -24.6763 264.5958 -44.5490 268.3607  -1.6025 270.2340 -24.9275 270.3614 -25.7767 274.0048 -14.0392 276.0963 -30.2162 285.1194 -24.8336 288.6522  11.1075 263.1828 -33.7212 263.4633 -36.5558

Post-slew

 Time interval of the image: 62.636600 171.000900 171.936000 963.071200

# RAcent #  [deg] 186.7265 -62.5820 244.9699 -15.6435 256.0033 -37.6945 256.4340 -36.4194 263.1671 -24.6682 264.7921 -44.5180 268.3936  -1.6004 270.2832 -25.0616 270.2963 -25.7920 274.1430 -13.9867 275.8897 -30.2747 284.8879 -24.9915 263.0931 -33.7273 220.3530 -20.7834 204.7772 -59.6810 292.4584  -1.8389

Mask shadow pattern

IMY = -1.299052556586335E-01 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] ['] 0.3 23.8 115.5 13.5028 37.4 0.4 Sco X-1 4.3 12.4 38.1 0.8310 2.7 4.4 4U 1700-377 4.5 11.2 41.1 0.7634 2.6 9.4 GX 349+2 0.0 5.2 137.2 0.2940 1.0 12.7 GX 1+4 3.9 15.7 0.8 0.8447 3.0 8.9 4U 1735-44 0.0 27.7 -179.9 -0.1296 -0.4 12.0 SW J1753.5-0127 1.8 5.2 -141.2 1.9135 6.4 0.6 GX 5-1 6.3 4.8 -133.9 0.5502 1.8 10.1 GRS 1758-258 20.8 16.4 -157.3 0.1740 0.6 9.0 GX 17+2 3.6 8.3 -81.8 0.9443 3.2 2.7 H1820-303 4.1 17.1 -102.6 -0.9508 -2.9 10.3 HT1900.1-2455 2.5 45.4 -152.2 3.0751 4.7 1.0 GRS 1915+105 9.6 5.7 25.7 0.3685 1.2 2.9 GX 354-0 2.4 49.0 -172.3 3.3664 4.9 ------ UNKNOWN 2.6 25.0 -148.0 1.4065 4.5 ------ UNKNOWN 2.5 34.7 -143.2 1.9292 4.6 ------ UNKNOWN 4.0 40.3 -144.7 1.5097 2.9 ------ UNKNOWN background subtracted image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 12.0 23.7 116.0 0.0934 1.0 12.6 Sco X-1 3.8 12.5 38.1 -0.2194 -3.1 9.2 4U 1700-377 2.1 11.3 41.0 0.3742 5.4 10.7 GX 349+2 24.8 5.3 139.3 -0.0330 -0.5 6.2 GX 1+4 2.9 15.7 0.9 -0.2962 -3.9 8.7 4U 1735-44 5.7 27.4 -179.6 0.1658 2.0 9.0 SW J1753.5-0127 11.4 5.3 -142.7 -0.0740 -1.0 9.5 GX 5-1 6.9 4.7 -135.1 -0.1245 -1.7 3.8 GRS 1758-258 77.7 16.5 -157.0 0.0112 0.1 0.2 GX 17+2 0.0 8.5 -83.0 -0.1006 -1.3 12.7 H1820-303 21.8 17.2 -103.4 0.0439 0.5 6.9 HT1900.1-2455 0.0 45.5 -152.5 -0.3308 -2.1 13.0 GRS 1915+105 10.5 5.5 25.3 -0.0770 -1.1 11.8 GX 354-0 2.1 8.0 13.4 0.3727 5.4 ------ UNKNOWN image of 15-350 keV band DECcent POSerr Theta Phi PeakCts SNR AngSep Name [deg] ['] [deg] [deg] ['] 4.8 48.8 33.5 8.8046 2.4 11.5 GX 301-2 0.3 23.5 149.4 36.6957 41.2 0.6 Sco X-1 4.2 1.0 26.1 2.2103 2.7 9.0 4U 1700-377 4.7 0.4 161.0 1.9757 2.5 0.2 GX 349+2 14.5 13.4 -154.8 0.6944 0.8 9.8 GX 1+4 28.9 9.9 -37.9 0.3324 0.4 4.6 4U 1735-44 4.5 36.9 -161.6 -2.5922 -2.5 9.0 SW J1753.5-0127 3.4 16.6 -132.8 2.5794 3.4 1.1 GX 5-1 2.6 16.0 -131.1 3.4893 4.5 3.0 GRS 1758-258 10.4 27.7 -142.5 1.0789 1.1 8.5 GX 17+2 4.5 17.3 -108.1 2.3042 2.6 5.8 H1820-303 4.1 26.9 -109.6 -3.3198 -2.8 9.1 HT1900.1-2455 5.6 6.1 -119.8 1.6825 2.1 8.3 GX 354-0 4.6 35.3 105.3 4.3495 2.5 ------ UNKNOWN 2.9 39.9 36.6 5.5110 4.0 ------ UNKNOWN 2.8 48.1 -129.7 16.5671 4.1 ------ 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 = 1.546298711303626E-01,

Spacecraft aspect plot

Bright

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