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Дата изменения: Mon Jul 9 08:24:31 2007
Дата индексирования: Sat Dec 22 11:06:43 2007
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Поисковые слова: arp 220

XMM-Newton Science Analysis System


omgchain (omgchain-1.6) [xmmsas_20070708_1801-7.1.0]

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• If the chain runs to completion, a number of important output files will appear. The chain product filenames have the extension `.FIT'. The names of the files start with `p' for the products and with `g' for the intermediate or auxiliar images and source lists.
• Some images of bright sources can be badly affected by the Mod-8 noise pattern (combined with coincidence loss). The spectra of such sources are unreliable.
• It is wise to check the output files (p* and g* files) from omgchain. A useful first step is to inspect the output PDF-spectra curve plots - watch out for frequent drop-outs, isolated high or substantial negative values. Establish that the background spectrum is reasonable. One should also examine the rotated image (produced by omgprep), for example, with the ftool, fv or with the ds9 programme. Check whether all the sources are detected. For this purpose overlay the image source list onto skymap usingimplot, e.g.

  implot set= sky_image_file.FIT withsrclistset=y srclistset=osw_source_list_file.FIT device=your_device (e.g. /XW) itv=1 radius=3 maxsrc=10 colour=7.