N_877 Scan 538

Contents

Observing log information

  Object:           N_877
  On scan num:      538 540 542
  Off scan num:     539 541 543
  R.A.:             2.299620 hrs
  Dec.:             14.540601 deg
  On azimuth:       183.275771 deg
  On zenith dist.:  23.841694 deg
  Off azimuth:      183.274402 deg
  Off zenith dist.: 23.841800 deg
  MJD:              52267
  UTC:              0.062419
  Center freq.:     1401.905428 MHz
  Doppler:          -0.00008311
  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:      0.097 Jy
  Lower 20% velocity: 3610.4 km/s
  Upper 20% velocity: 4149.4 km/s
   Systemic velocity: 3879.9 km/s
   Line width (20%):   539.0 km/s
  Profile integral:   38.73 Jy * km/s
                 A:   31.26
                 B:   40.32
         Ratio B/A:   1.290
  Flux integral
     velocity range:  3517.2 - 4215.1 km/s

Comments

extended wing at 20 percent level on low velocity side included in profile width