N4680 Scan 122

Contents

Observing log information

  Object:           N4680
  On scan num:      122 124 126 128 130 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 170
  Off scan num:     123 125 127 129 131 135 137 139 141 143 145 147 149 151 153 155 157 159 161 163 165 167 169 171
  R.A.:             12.781865 hrs
  Dec.:             -11.636822 deg
  On azimuth:       134.884367 deg
  On zenith dist.:  62.291611 deg
  Off azimuth:      134.845796 deg
  Off zenith dist.: 62.315070 deg
  MJD:              52769
  UTC:              0.010324
  Center freq.:     1408.622445 MHz
  Doppler:          -0.00005232
  Num. correlators: 2
  Spectrom. atten.: 0 0 dB
  Bandwidth:        12.5 MHz
  Num. channels:    8192
  Eff. integration: 6912 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.

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.021 Jy
  Lower 20% velocity: 2312.3 km/s
  Upper 20% velocity: 2542.6 km/s
   Systemic velocity: 2427.4 km/s
   Line width (20%):   230.3 km/s
  Profile integral:    4.10 Jy * km/s
                 A:    3.96
                 B:    4.25
         Ratio B/A:   1.072
  Flux integral
     velocity range:  2259.5 - 2589.4 km/s

Comments