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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.

omsource imageset=/path_to_your_data/proc/P0125321001OMS006IMAGE_0000.FIT   [optional parameter]
7.0.0srclistset=/path_to_your_data/proc/a_name_for_my_7.0.0_list.FIT  [optional parameter]
 oldsrclistset=/path_to_your_data/proc/P0125321001OMS006SWSRLI0000.FIT [optional parameter]

 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:

OM image to analyse

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 Photometry] button.

Performing photometry with omsource

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.