U8801 Scan 172


Observing log information

  Object:           U8801
  On scan num:      172 174 176 178 180 182 184 186 188 190 192 194
  Off scan num:     173 175 177 179 181 183 185 187 189 191 193 195
  R.A.:             13.892198 hrs
  Dec.:             -1.194365 deg
  On azimuth:       121.644515 deg
  On zenith dist.:  58.012066 deg
  Off azimuth:      121.607447 deg
  Off zenith dist.: 58.039999 deg
  MJD:              52379
  UTC:              0.106215
  Center freq.:     1387.561324 MHz
  Doppler:          0.00000559
  Num. correlators: 2
  Spectrom. atten.: 38 39 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 3300 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 10 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 10 channels by interpolation between the nearest valid channels

Figure 3. Measured spectrum

Measured parameters

  Peak intensity:      0.016 Jy
  Lower 20% velocity: 6920.9 km/s
  Upper 20% velocity: 7293.1 km/s
   Systemic velocity: 7107.0 km/s
   Line width (20%):   372.2 km/s
  Profile integral:    4.32 Jy * km/s
                 A:    3.94
                 B:    4.34
         Ratio B/A:   1.100
  Flux integral
     velocity range:  6905.8 - 7307.6 km/s