Interactive photometry on OM data with SAS: omsource
If the results obtained after running omichain
are not satisfactory, e.g. an interesting source has not been detected,
the user can perform the photometry in a fully interactive way.
Invoking omsource will allow us to select the desired source and
to adjust the aperture and background region sizes so as to
obtain its count rate and magnitude with all the necessary corrections.
A detailed description of this task can be found in the SAS
documentation, both in HTML and Postscript format.
The input for omsource is an image file that
has gone through all steps of the image processing up to source
detection (see OM
image processing threads). This input image can be entered in the
command line as a parameter, or it can be selected from a pop-up menu.
The user can provide an existing source list. Then, the existing
sources can be modified and/or 7.0.0 sources can be added interactively.
The image MUST NOT have been processed by omatt. In other
words, north aligned images produced by the Pipeline or by using omatt are not
valid for omsource
The image is displayed by DS9, and an interactive menu allows us
to start the source selection:
The first menu allows the user to enter an existing source list [Load source-list], or to start
selecting targets with the cursor [Select
sources]. When list loading or 7.0.0 sources selection is
completed, then a second menu will appear and the photometric
parameters for each source can be changed. Final computation is
achieved by pushing the [Compute
Upon Exit, we shall be prompted for a name for the 7.0.0 source list, if
it was not given in the command line.