XMM-Newton Science Analysis System: User Guide


next up previous contents
Next: 5.7.1 Generating RGS images Up: 5 Analysis of RGS spectrometer data Previous: 5.6.3 The class of cool pixels

5.7 The use of xmmselect on RGS data

Although the spectra and response matrices produced by rgsproc are usually trustworthy, it is worthwhile getting to know the events files on which they are based as well as making routine checks on the data. As its name suggests, xmmselect

http://xmm.esac.esa.int/sas/current/doc/xmmselect/index.html

is a tool for the manipulation and display of XMM-Newton data in general including RGS event files via a GUI and is often invoked as a background process

 xmmselect table=P0136540101R1S001EVENLI0000.FIT:EVENTS &

to provide a graphical interface to evselect, its command-line equivalent (figure 33).

Figure 33: A common use of xmmselect is to inspect details of RGS data. In this example, the user has pressed the CCDNR button after adjusting the adjacent minimum and maximum values to select CCD 5 only. The selection criterion is then shown in the top window. Columns MLAMBDA and XDSP_CORR have been selected using the checkboxes on the left in preparation for pressing the Image button to produce a pointing-corrected spatial plot of the data of the single CCD selected.
\scalebox{0.7}{\includegraphics{RGS/xmmselect_v9.ps}}

illustrates the main panel of xmmselect in use on an RGS1 event list. It is possible to specify both simple selection criteria, such as the one shown there, or the more complex RGS spectrum regions discussed above in § 5.6.1 before making an image, for example. For every operation, xmmselect displays the results and writes them to an appropriate standard-format FITS file. The displays are done by launching automatically one of several flexible third-party graphical tools, such as ds9 [24], that allow a great deal of flexibility in tailoring plots to individual requirements. It is always possible to choose the name of the file in which the results are recorded to overrule the default name that otherwise will appear, perhaps unexpectedly, in the working directory.

Figure 34: The xmmselect Image panel is shown here for preparing a MLAMBDA/PI banana plot. Values have been specified for imageset, the image output file, and for a y-axis range suitable for the range of photon PI values. Pressing the Run button gets the work done.
\scalebox{0.8}{\includegraphics{RGS/xmmselect_image_v9.ps}}

As a matter of routine, it is advisable to look at MLAMBDA/XDSP_CORR and MLAMBDA/PI plots of the screened event list and source and background light curves to be able to make a critical assessment of the



Subsections
next up previous contents
Next: 5.7.1 Generating RGS images Up: 5 Analysis of RGS spectrometer data Previous: 5.6.3 The class of cool pixels
European Space Agency - XMM-Newton Science Operations Centre