Pisces Scan 600


Observing log information

  Object:           Pisces
  On scan num:      600
  Off scan num:     601
  R.A.:             1.065697 hrs
  Dec.:             21.894697 deg
  On azimuth:       98.255627 deg
  On zenith dist.:  43.429298 deg
  Off azimuth:      98.221520 deg
  Off zenith dist.: 43.465209 deg
  MJD:              52498
  UTC:              0.242894
  Center freq.:     1419.580800 MHz
  Doppler:          0.00008591
  Num. correlators: 2
  Spectrom. atten.: 39 37 dB
  Bandwidth:         5.0 MHz
  Num. channels:    1024
  Eff. integration: 300 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:      0.113 Jy
  Lower 20% velocity: -300.8 km/s
  Upper 20% velocity: -269.4 km/s
   Systemic velocity: -285.1 km/s
   Line width (20%):    31.4 km/s
  Profile integral:    2.26 Jy * km/s
                 A:    2.20
                 B:    2.23
         Ratio B/A:   1.014
  Flux integral
     velocity range:  -303.7 - -263.6 km/s


very little baseline on negative velocity side, could be a high velocity cloud