N7769 Scan 129


Observing log information

  Object:           N7769
  On scan num:      129 131 133
  Off scan num:     130 132 134
  R.A.:             23.851035 hrs
  Dec.:             20.149416 deg
  On azimuth:       173.999483 deg
  On zenith dist.:  18.294503 deg
  Off azimuth:      174.023346 deg
  Off zenith dist.: 18.293795 deg
  MJD:              52456
  UTC:              0.432535
  Center freq.:     1400.891977 MHz
  Doppler:          0.00009216
  Num. correlators: 2
  Spectrom. atten.: 41 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 840 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 2 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.

Figure 3. Measured spectrum

Measured parameters

  Peak intensity:      0.039 Jy
  Lower 20% velocity: 4016.4 km/s
  Upper 20% velocity: 4419.2 km/s
   Systemic velocity: 4217.8 km/s
   Line width (20%):   402.8 km/s
  Profile integral:   11.55 Jy * km/s
                 A:   12.29
                 B:   12.74
         Ratio B/A:   1.036
  Flux integral
     velocity range:  3962.2 - 4494.2 km/s


poor baseline, questionable flux density integral and profile edge locations