Joachim Köppen Strasbourg Feb. 2013

The data are shown in a false colour longitude-vrad map for galactic longitude (from 4° to 240° in steps of 2°) and radial velocity from -200 to +200 km/s.

Here are brief instructions:

• File Info gives some technical details of the data file
• freq.smooth allows to apply a smoothing of the spectra over an intervall of the indicated number of frequency points.
• Long-Vrad map is a false colour map of the intensity as a function of galactic longitude and radial velocity.
  • clicking on the map will display the x, y, and z values of that point, i.e. longitude, radial velocity, and intensity.
  • drag & zoom: click this button, then drag the mouse over the portion of the map that you want to be zoomed.
  • unzoom brings back the full view.
  • the Map colour coding can be chosen among several options.
    The coding is shown as a thin bar at the right hand side of the map, from minimum to maximum value of the chosen range.
  • one may chose between autorange or manual cuts. For the latter, the min and max values can be entered in the fields below the button.
  • the white vertical line indicates the longitude whose spectrum can be plotted.
• x-y map is a false colour map of the intensity as if we would look down on the Galactic Plane.
  The white line indicates the line-of-sight at the longitude chosen with the stepping buttons.
  Note: the colour coding is identical to the one of the l-v map.
• Gauss fit allows to fit the spectrum of a galactic longitude with Gaussian components of different radial velocities.
  • empty button will show green if the corresponding component has been chosen and is displayed.
  • grab: click this for a chosen component, then click on the plot where you want the Gaussian curve's peak to be placed.
  • c is the center velocity. One can also enter the value manually, followed by hitting the Enter key.
  • w is the FWHM of the component.
  • h is the peak value of the component.
  • Sum curve shows the sum of all chosen components,, components shows all individual components.
• plot shows the spectrum at a galactic longitude. Clicking on the plot will display the x=radial velocity and y=intensity of that point.
• with the buttons -50 ... +50 one can step back and forth in longitude.
• Output shows the displayed spectrum (including smoothing) at the chosen longitude as a numerical table. It can be copied and pasted into a text editor.