NGC986 Scan 974


Observing log information

  Object:           NGC986
  On scan num:      974 976 978 980 982 984
  Off scan num:     975 977 979 981 983 985
  R.A.:             2.559485 hrs
  Dec.:             -39.044486 deg
  On azimuth:       183.204806 deg
  On zenith dist.:  77.412740 deg
  Off azimuth:      183.168300 deg
  Off zenith dist.: 77.410931 deg
  MJD:              52532
  UTC:              0.354271
  Center freq.:     1411.005823 MHz
  Doppler:          0.00002588
  Num. correlators: 2
  Spectrom. atten.: 35 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.

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.127 Jy
  Lower 20% velocity: 1909.3 km/s
  Upper 20% velocity: 2047.7 km/s
   Systemic velocity: 1978.5 km/s
   Line width (20%):   138.3 km/s
  Profile integral:   13.47 Jy * km/s
                 A:   12.45
                 B:   13.80
         Ratio B/A:   1.109
  Flux integral
     velocity range:  1860.9 - 2126.1 km/s