N2227 Scan 189

Contents

Observing log information

  Object:           N2227
  On scan num:      189 191 193 195 197 199 201 203 205 207 209 211
  Off scan num:     190 192 194 196 198 200 202 204 206 208 210 212
  R.A.:             6.432785 hrs
  Dec.:             -22.004612 deg
  On azimuth:       161.474790 deg
  On zenith dist.:  62.566489 deg
  Off azimuth:      161.436666 deg
  Off zenith dist.: 62.576163 deg
  MJD:              52421
  UTC:              0.758021
  Center freq.:     1409.786470 MHz
  Doppler:          -0.00003713
  Num. correlators: 2
  Spectrom. atten.: 35 37 dB
  Bandwidth:         5.0 MHz
  Num. channels:    1024
  Eff. integration: 3600 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 4th-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:      0.069 Jy
  Lower 20% velocity: 2117.4 km/s
  Upper 20% velocity: 2398.2 km/s
   Systemic velocity: 2257.8 km/s
   Line width (20%):   280.8 km/s
  Profile integral:   13.16 Jy * km/s
                 A:   11.56
                 B:   13.81
         Ratio B/A:   1.195
  Flux integral
     velocity range:  2087.1 - 2429.2 km/s

Comments