127-082 Scan 2478


Observing log information

  Object:           127-082
  On scan num:      2478 2480 2482 2484 2486 2488 2490 2492 2494
  Off scan num:     2479 2481 2483 2485 2487 2489 2491 2493 2495
  R.A.:             11.866736 hrs
  Dec.:             21.109953 deg
  On azimuth:       186.969642 deg
  On zenith dist.:  17.386752 deg
  Off azimuth:      187.021060 deg
  Off zenith dist.: 17.388285 deg
  MJD:              52255
  UTC:              0.495104
  Center freq.:     1389.683191 MHz
  Doppler:          0.00009560
  Num. correlators: 2
  Spectrom. atten.: 34 39 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 2700 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 5 channels by interpolation between the nearest valid channels

Figure 2. Measured spectrum

Measured parameters

  Peak intensity:      0.010 Jy
  Lower 20% velocity: 6538.7 km/s
  Upper 20% velocity: 6763.1 km/s
   Systemic velocity: 6650.9 km/s
   Line width (20%):   224.4 km/s
  Profile integral:    1.86 Jy * km/s
                 A:    1.58
                 B:    2.02
         Ratio B/A:   1.278
  Flux integral
     velocity range:  6522.9 - 6779.1 km/s