Obtaining XMM-OM data

The XMM Optical Monitor data (XMM-OM) are provided to MAST by the XMM-Newton Guest Observer Facilty located at HEASARC at Goddard Space Flight Center. The raw data are accessible via links to HEASARC while the mosaic image files are stored online at MAST as gzipped FITS files.

Normally web users will search the XMM-OM database using the XMM-OM search page. The returned table of found entries allows the user to mark files (i.e., the mosaiced images and source files) to be downloaded. A request for data begins a retrieval job. Once the requested files are located, they are written to a data distribution disk area on the system, bundled into a tar, zipped format file, and downloaded to the disk area specified by the user in the "save as..." pop-up window. The files have finished downloading when the pop-up window disappears. The wait time will be proportional to the number of images requested. Also shown in the search results page is a column titled "Raw Files" which provides links to HEASARC to download the raw data files (as well as the mosaiced images) by dataid. The links connect to a main directory with 3 subdirectories for each file type: ODF, PPS, and om_mosaic.

File access is also possible from the XMM-OM preview pages which are also accessed via links from the search results page. Clicking on the entries in the Dataid column will display a web page displaying the mosaic images, and providing links to the individual files. The mosaics are shown as 512x512 jpg images, but clicking on the images will display the full resolution image. Links are also available for displaying the FITS mosaic image uaing Aladin or for downloading the tar file of gzipped images.

Primary access is via the web although FTP access is also possible using either a web browser (i.e. ftp://archive.stsci.edu/pub/xmm-om/data/), or, as explained below, using anonymous ftp from an ordinary terminal with network access.

As an example, a typical interactive ftp session to retrieve files for observation 0301270501 would be: