XMM-Newton Users Handbook


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3.5.10.1 Choice of Science User Defined non-default windows

For OM observations more than one science window may be defined. The different science windows may overlap without loss of information in any of these windows. Especially, a FAST mode WINDOW inside an IMAGE mode WINDOW does not punch a hole into the image, thus, the source will be in the image and in the fast window.

There are several boundary conditions that limit the user's choice and which must be taken into account properly if a non-default window configuration is going to be used.

Figure 111: When the boundaries of OM science windows are defined in detector pixel coordinates, the relative location of the windows with respect to each other does not change. However, different areas on the sky are imaged under different position angles.
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Figure 112: Defining the locations of OM science windows in sky coordinates one makes sure that (approximately) the same area of the sky is imaged under different position angles. However, the OM science windows can change their relative locations. Windows 3 and 5 (which used to be in the upper left corner of window 3, see previous figure) are now partially overlapping, which is not allowed and window 4 is now partly outside the OM FOV (which is also not allowed).
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For a more detailed explanation the reader may refer to the technical note on Constraints on the OM Window Configuration and Definition of the OM Default Configurations (§ 7).

An interactive tool for planning OM observations of point sources is available at the MSSL URL: http://www.mssl.ucl.ac.uk/www_astro/xmm/om/om_tool_current.html

Another tool to help defining OM science windows is available at:
http://www.mssl.ucl.ac.uk/www_astro/xmm/om/om_wintool/om_tool2.html
This interactive tool may help defining and visualising OM Science Windows and mapping out the dispersion direction of the grisms for different position angles to check for a possible superposition with a bright star.

An interactive grism tool for planning OM grism observations is available at:
http://www.mssl.ucl.ac.uk/www_astro/xmm/om/grism_tool_current.html.


next up previous contents
Next: 3.6 XMM-Newton support instruments Up: 3.5.10 OM specific proposal submission information Previous: 3.5.10 OM specific proposal submission information
European Space Agency - XMM-Newton Science Operations Centre