User manual

to select a column by a simple click on it in the measure panel. To do so, you need to

choose the sub-menu “Pick…” when you click on “Columns” or “UCDs”.

Physical units

Indicating physical units (e.g. arcmin, Jy, …) in the test enables you to get rid of the

manual conversion for expressions using columns in which values are not expressed in

the same unit. Units can be made as shown in the following example. This is a powerful

example to describe generic filters.

Example: Drawing a circle proportional to the X flux (UCD :

phot.flux;em.X-ray) for all sources for which the energy level is higher

than the given threshold

$[phot.flux;em.X-ray]>10^-8 erg/m^2/s

{ draw circle($[phot.flux;em.X-ray]) }

Modifying a filter

To find again a filter editing window, you need to select the corresponding filter in the

stack and show its properties with the menu “Edit => Properties”.

Extending the implementation of a filter

To be implemented, a filter has to be activated with the check close

to its logo in the stack. By default, a filter is applied to all the

catalogues planes that are below in the Aladin stack. However, if a

filter is located in a directory in the stack, it will only be

implemented to the catalogue planes belonging to this directory.