I_357 Scan 194


Observing log information

  Object:           I_357
  On scan num:      194 196 198
  Off scan num:     195 197 199
  R.A.:             4.062250 hrs
  Dec.:             22.158244 deg
  On azimuth:       275.446178 deg
  On zenith dist.:  59.687205 deg
  Off azimuth:      275.419188 deg
  Off zenith dist.: 59.651418 deg
  MJD:              52263
  UTC:              0.331863
  Center freq.:     1390.893470 MHz
  Doppler:          -0.00004446
  Num. correlators: 2
  Spectrom. atten.: 34 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 900 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:      0.058 Jy
  Lower 20% velocity: 6167.2 km/s
  Upper 20% velocity: 6421.0 km/s
   Systemic velocity: 6294.1 km/s
   Line width (20%):   253.7 km/s
  Profile integral:   10.89 Jy * km/s
                 A:    8.91
                 B:   11.50
         Ratio B/A:   1.291
  Flux integral
     velocity range:  6094.3 - 6655.4 km/s


very long wing extending to about 6600 km/s, 20 percent edge very poorly defined