UGC8801 Scan 123


Observing log information

  Object:           UGC8801
  On scan num:      123 125 127 129 131 133 135
  Off scan num:     124 126 128 130 132 134 136
  R.A.:             13.892159 hrs
  Dec.:             -1.193895 deg
  On azimuth:       133.567606 deg
  On zenith dist.:  50.355534 deg
  Off azimuth:      133.536052 deg
  Off zenith dist.: 50.372169 deg
  MJD:              52256
  UTC:              0.476181
  Center freq.:     1387.667586 MHz
  Doppler:          0.00008217
  Num. correlators: 2
  Spectrom. atten.: 34 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 2100 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 4 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.016 Jy
  Lower 20% velocity: 6913.3 km/s
  Upper 20% velocity: 7294.1 km/s
   Systemic velocity: 7103.7 km/s
   Line width (20%):   380.9 km/s
  Profile integral:    4.42 Jy * km/s
                 A:    3.38
                 B:    4.59
         Ratio B/A:   1.359
  Flux integral
     velocity range:  6898.9 - 7313.5 km/s