To extract data for one source, identify the source in the full image you just made above. Move the mouse cursor over the brightest pixel of the source to get the source position in X- and Y-coordinates. It helps to use linear intensity scaling.

To extract the source spectrum, event list, image, and pile-up information, call xmmextract with a calling sequence similar to the following line (again, it is best to do this in a script!):

${xmmextract} --logfile="j1708_pn.log" --prepdir=${odf} \
     --name="j1708" --pn \
     --singles  --doubles \
     --srcx=27525 --srcy=27971 --rad=1200  \
     --bkginrad=1500 --bkgoutrad=2000 

Here, the --srcx and --srcy arguments are the source position from above. rad gives the extraction radius for the source, which is extracted using a circular aperture with this radius (this is in units of 0.05 arcseconds. By default, the background is extracted from an annulus centred on the source with the inner and outer radii given by the bkginrad and bkgoutrad options.

Repeat the call to xmmextract, substituting --mos1 or --mos2 for the --pn argument to perform the extraction for MOS1 and MOS2.

The call generates a new directory, called j1708 in the above example containing a few subdirectories with self-explanatory names. Amongst others, these directories contain an events directory, containing the events data, a directory containing the source and background spectrum, as well as response matrix and anciliary response information for spectral fitting, and a directory containing the source and background images. Check these to see whether any fainter sources contaminate your extraction!

Since the response matrix generation takes a rather long time, if spectral analysis is not to be performed, it is recommended to switch off the response matrix generation (e.g., if source timing is to be performed) by adding the --nomakersp switch to the above call to xmmextract. Furthermore, you can switch off the spectrum generation and the lightcurve generation with the --nomakepha and --nomakelc arguments.

A full list of xmmextract's keywords can be obtained by running

xmmextract --help