N00496 Scan 857


Observing log information

  Object:           N00496
  On scan num:      857 859 861 863 865
  Off scan num:     858 860 862 864 866
  R.A.:             1.386602 hrs
  Dec.:             33.529610 deg
  On azimuth:       71.146659 deg
  On zenith dist.:  56.615890 deg
  Off azimuth:      71.125737 deg
  Off zenith dist.: 56.650103 deg
  MJD:              52508
  UTC:              0.161308
  Center freq.:     1392.639977 MHz
  Doppler:          0.00008135
  Num. correlators: 2
  Spectrom. atten.: 41 42 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 1380 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

Edited spectrum

This spectrum is the same as Figure 1 but with 3 60-second sub-integrations manually deleted because of interference or a bad baseline.

Figure 2. Edited 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 2.

Figure 3. Measured spectrum

Measured parameters

  Peak intensity:      0.028 Jy
  Lower 20% velocity: 5839.0 km/s
  Upper 20% velocity: 6161.1 km/s
   Systemic velocity: 6000.0 km/s
   Line width (20%):   322.1 km/s
  Profile integral:    6.96 Jy * km/s
                 A:    6.45
                 B:    7.17
         Ratio B/A:   1.112
  Flux integral
     velocity range:  5804.4 - 6183.9 km/s


More HI to high velocity side not included in width and flux integral.