N5936 Scan 743


Observing log information

  Object:           N5936
  On scan num:      743 745 747
  Off scan num:     744 746 748
  R.A.:             15.500224 hrs
  Dec.:             12.989046 deg
  On azimuth:       112.464661 deg
  On zenith dist.:  45.151182 deg
  Off azimuth:      112.433566 deg
  Off zenith dist.: 45.175318 deg
  MJD:              52262
  UTC:              0.503426
  Center freq.:     1401.449375 MHz
  Doppler:          0.00005834
  Num. correlators: 2
  Spectrom. atten.: 34 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 720 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

Edited spectrum

This spectrum is the same as Figure 1 but with 6 60-second sub-integrations manually deleted because of interference or a bad baseline.

Figure 2. Edited 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 2. Narrow band interference was removed from 3 channels by interpolation between the nearest valid channels

Figure 3. Measured spectrum

Measured parameters

  Peak intensity:      0.030 Jy
  Lower 20% velocity: 3899.7 km/s
  Upper 20% velocity: 4129.7 km/s
   Systemic velocity: 4014.7 km/s
   Line width (20%):   230.0 km/s
  Profile integral:    5.48 Jy * km/s
                 A:    4.15
                 B:    5.61
         Ratio B/A:   1.351
  Flux integral
     velocity range:  3875.8 - 4174.2 km/s


high velocity wing very poorly defined at 20 percent level