N0845 Scan 758


Observing log information

  Object:           N0845
  On scan num:      758 760 762 764 766 768
  Off scan num:     759 761 763 765 767 769
  R.A.:             2.205569 hrs
  Dec.:             37.478373 deg
  On azimuth:       273.480832 deg
  On zenith dist.:  16.966265 deg
  Off azimuth:      273.293759 deg
  Off zenith dist.: 16.656709 deg
  MJD:              52244
  UTC:              0.177315
  Center freq.:     1399.279153 MHz
  Doppler:          -0.00004055
  Num. correlators: 2
  Spectrom. atten.: 33 39 dB
  Bandwidth:         5.0 MHz
  Num. channels:    1024
  Eff. integration: 1800 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. Narrow band interference was removed from 24 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.006 Jy
  Lower 20% velocity: 4206.6 km/s
  Upper 20% velocity: 4631.8 km/s
   Systemic velocity: 4419.2 km/s
   Line width (20%):   425.2 km/s
  Profile integral:    1.47 Jy * km/s
                 A:    1.44
                 B:    1.86
         Ratio B/A:   1.289
  Flux integral
     velocity range:  4192.8 - 4644.9 km/s


just a guess at where wings are, especially low velocity side