NGC985 Scan 655

Contents

Observing log information

  Object:           NGC985
  On scan num:      655 657 659 661 663 665 667 669 671 673 675 677 679 681 683 685 687 689 691 693 695 697 699 701
  Off scan num:     656 658 660 662 664 666 668 670 672 674 676 678 680 682 684 686 688 690 692 694 696 698 700 702
  R.A.:             2.577051 hrs
  Dec.:             -8.785452 deg
  On azimuth:       152.501052 deg
  On zenith dist.:  51.119423 deg
  Off azimuth:      152.466061 deg
  Off zenith dist.: 51.130205 deg
  MJD:              52280
  UTC:              0.972731
  Center freq.:     1362.771917 MHz
  Doppler:          -0.00008873
  Num. correlators: 2
  Spectrom. atten.: 35 40 dB
  Bandwidth:        10.0 MHz
  Num. channels:    1024
  Eff. integration: 7200 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 6 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:      0.005 Jy
  Lower 20% velocity: 12568.6 km/s
  Upper 20% velocity: 13171.7 km/s
   Systemic velocity: 12870.2 km/s
   Line width (20%):   603.1 km/s
  Profile integral:    1.96 Jy * km/s
                 A:    0.77
                 B:    1.98
         Ratio B/A:   2.590
  Flux integral
     velocity range:  12522.3 - 13201.7 km/s

Comments

very weak and messy profile, edge locations are only guesses