LVM218. Scan 135

Contents

Observing log information

  Object:           LVM218.
  On scan num:      135 137 139 141 143 145
  Off scan num:     136 138 140 142 144 146
  R.A.:             7.993502 hrs
  Dec.:             71.752712 deg
  On azimuth:       22.329344 deg
  On zenith dist.:  55.057140 deg
  Off azimuth:      22.322286 deg
  Off zenith dist.: 55.075948 deg
  MJD:              52287
  UTC:              0.976181
  Center freq.:     1395.675242 MHz
  Doppler:          -0.00001032
  Num. correlators: 2
  Spectrom. atten.: 34 39 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 1800 seconds

Raw spectrum

This spectrum is the integration of all data for the scan with spectra from both polarizations added together. The spectral intensities are Ssys * (on - off) / off, where Ssys is the system temperature in Jy. The system noise flux density equivalent is calibrated for each scan with a calibration noise source firing during each scan. The cal value, in Jy, is calibrated by comparison with a number of continuum sources as described in the summary web page

Figure 1. Unedited spectrum

Measured spectrum

This is the section of spectrum measured to obtain the parameters listed below. The three horizontal dotted lines are the baseline, the peak level selected, and 20% of the peak level. The two vertical dotted lines mark the selected 20% line width edges. The solid horizontal line marks the velocity range chosen for the the line profile flux density integral. This spectrum has a second-order least squares fit baseline removed using most of the baseline shown in Figure 1. Narrow band interference was removed from 3 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.014 Jy
  Lower 20% velocity: 5103.2 km/s
  Upper 20% velocity: 5291.1 km/s
   Systemic velocity: 5197.1 km/s
   Line width (20%):   187.9 km/s
  Profile integral:    2.11 Jy * km/s
                 A:    1.56
                 B:    2.17
         Ratio B/A:   1.392
  Flux integral
     velocity range:  5097.9 - 5298.4 km/s

Comments