3D mode

Top row : pixel-based and channel-based plot. Scales are in Jy/beam (or K)

  • Image on the left : channel map extracted from a channel (frequency) selected in the top-right spectrum
  • Spectrum on the right : spectrum of a given pixel selected in the top-left image

Bottom row : averages : area-based and frequency range-based plot.

  • Image on the left : map averaged from a frequency-range (velocity-range) selected in the bottom-right spectrum. The scale is in Jy/beam.km/s
  • Spectrum on the right : spectrum averaged over all pixels inside a box selected in the bottom-left image. The scale is in Jy.

For more informations you can also take a look at :


How to search for emission lines ?

  • Define a box (clic and drag) in the central region of the Bottom-Left image, where the signal appears
  • Select the box (mouse click on the box) to compute the averaged spectrum on the bottom-right panel.
  • Select a frequency range (click and drag) in the bottom-right plot (the selected range appears in blue). This will compute and display the averaged image in the bottom-left plot.
  • The title of the bottom-left spectrum gives the integrated emission line inside the selected box and frequency range in Jy.km/s and the selected velocity range.

How to guess the redshift and overplot markers ?

  • Click on Search : this will resolve the source coordinates in NED and list the possible sources in the FoV.
  • In order to select a source, click on one line of the Table in the pop-up window (click on the line, not on the link : the link is to go to NED). This will draw a marker at the position of the source. It will also select the redshift as a reference redshift to doppler shift molecular line rest frequencies.

How to overplot molecular species ?

  • Once the redshift has been selected (see above) : click on Show Lines after selection
  • Select a frequency range (blue area) to search for theoretical redshifted frequency in the selected range. Vertical lines in orange display the expected transition frequencies
  • Use the filters to change molecular catalogues, apply filters (Intensity, Energy, number of atoms…)
  • The list of molecular transitions found is listed in the table on the right. Use the > and >> button to see all the possible lines.
  • Select one line inside this Table (click on one specie on the left hand side list of species) to compute the Line Luminosity (displayed at the top of the Table).

How to check the predicted line frequencies for a given species ?

  • specify a given species (ie CO) in the search field under the « Show line after selection » checkbox
  • Click on the Dataset button that appeared. It lists all the transitions of this given species.
  • A list of transitions is displayed. A small arrow appears in front of the line if the transition is in the datacube.

How do I remove the boxes ?

  • Select a box (click on the box), then type x on your keyboard. The box will be removed from the plot.

How do I center the map ?

  • Use the central button of the mouse. Click and drag the map at the position you want.

How to compare to optical data in Aladin ?

  • Open Aladin on your computer (ie https://aladin.u-strasbg.fr/AladinDesktop/)
  • Click on the Hub icon (top-right in the menu) and register to Aladin Hub
  • A new arrow appears on the images (and in the spectra)
  • Click on this arrow to export the image into Aladin

How to export the spectrum into CASSIS ?

  • Open Cassis on your computer (ie http://cassis.irap.omp.eu/?page=installation)
  • Click on the Hub icon (top-right in the menu) and register to Cassis Hub
  • A new arrow appears on the images (and in the spectra)
  • A new button (Samp) appears on the spectra
  • Click on this button to export the spectrum into Cassis

How to export the spectrum into CLASS ?

  • Click on Save to download the 1D spectrum in FITS format
  • On you local computer, open CLASS (ie https://www.iram.fr/IRAMFR/GILDAS/gildasli2.html
  • CLASS > fits read averageSpectrumXXXX.fits
  • CLASS > plot

How to open the images from the 3D viewer (left hand-side plots) into the 2D viewer ?

  • Inside the images, click on the small icon with a filled circle. This will open the intensity moment map (bottom plot) into the 2D viewer. Use the same icon in order to open one channel map in the 2D viewer

How to apply a spectral smooth on the data ?

  • Choose the number of channels you want to smooth (form on the right hand side) and click either on the View button to open a new 3D viewer with the smoothed data cube or click on Download to retrieve the new cube

How do I change the colors ?

  • On the top-left black menu, click on the 3 lines, this will open a menu where you can modify the color options and scaling.