N_877 Scan 960


Observing log information

  Object:           N_877
  On scan num:      960 962 964
  Off scan num:     961 963 965
  R.A.:             2.299620 hrs
  Dec.:             14.540600 deg
  On azimuth:       219.306085 deg
  On zenith dist.:  28.832412 deg
  Off azimuth:      219.276294 deg
  Off zenith dist.: 28.823958 deg
  MJD:              52284
  UTC:              0.063299
  Center freq.:     1401.886454 MHz
  Doppler:          -0.00009664
  Num. correlators: 2
  Spectrom. atten.: 33 38 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 900 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 8 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.102 Jy
  Lower 20% velocity: 3663.7 km/s
  Upper 20% velocity: 4139.5 km/s
   Systemic velocity: 3901.6 km/s
   Line width (20%):   475.8 km/s
  Profile integral:   37.59 Jy * km/s
                 A:   29.79
                 B:   37.19
         Ratio B/A:   1.248
  Flux integral
     velocity range:  3529.9 - 4196.1 km/s


extended low level wing on low velocity side