LVM172. Scan 1008


Observing log information

  Object:           LVM172.
  On scan num:      1008 1010
  Off scan num:     1009 1011
  R.A.:             6.762859 hrs
  Dec.:             46.049255 deg
  On azimuth:       304.839626 deg
  On zenith dist.:  15.683721 deg
  Off azimuth:      304.875182 deg
  Off zenith dist.: 15.659382 deg
  MJD:              52284
  UTC:              0.249410
  Center freq.:     1392.018931 MHz
  Doppler:          -0.00001814
  Num. correlators: 2
  Spectrom. atten.: 33 38 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 600 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 5 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.007 Jy
  Lower 20% velocity: 5972.4 km/s
  Upper 20% velocity: 6318.9 km/s
   Systemic velocity: 6145.6 km/s
   Line width (20%):   346.6 km/s
  Profile integral:    1.76 Jy * km/s
                 A:    1.34
                 B:    1.59
         Ratio B/A:   1.191
  Flux integral
     velocity range:  5960.1 - 6335.8 km/s


very low SNR