N2748 Scan 154

Contents

Observing log information

  Object:           N2748
  On scan num:      154 156 158 160 162 164 166 168 170 172 174 176
  Off scan num:     155 157 159 161 163 165 167 169 171 173 175 177
  R.A.:             9.228613 hrs
  Dec.:             76.475877 deg
  On azimuth:       352.079777 deg
  On zenith dist.:  39.152699 deg
  Off azimuth:      352.101431 deg
  Off zenith dist.: 39.145260 deg
  MJD:              52343
  UTC:              0.199560
  Center freq.:     1413.378259 MHz
  Doppler:          -0.00004852
  Num. correlators: 2
  Spectrom. atten.: 35 42 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 second-order least squares fit baseline removed using most of the baseline shown in Figure 1.

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.157 Jy
  Lower 20% velocity: 1325.4 km/s
  Upper 20% velocity: 1633.8 km/s
   Systemic velocity: 1479.6 km/s
   Line width (20%):   308.4 km/s
  Profile integral:   39.22 Jy * km/s
                 A:   36.37
                 B:   39.16
         Ratio B/A:   1.077
  Flux integral
     velocity range:  1301.3 - 1657.3 km/s

Comments