EIS CoaddedImage Server: Output Formats

Output images from the Online EIS at ESO/ST-ECF are delivered FITS format. You can choose to display the images directly instead of first saving them to disk.

Image sizes for FITS, gzipped FITS are 618kB and 300kB respectively for a field of 10*10 arc minutes. There's a limit of 2048 x 2048 pixels (roughly 18*18 arcmin.), which corresponds to the size of one of the coadded sections.

For image display, we use MIME (Multi Purpose Internet Mail Extensions) types to launch an appropriate application at your site. You might have to configure the global or personal .mailcap file at your site to map the application/x-fits type to a FITS image viewer. FITS is the standard astronomical data interchange format. Possible viewers are xv, SAOimage or FITSview (MS-Windows). University of Iowa offers an exhaustive list of FITS viewers.

The latest version of the ESO SkyCat Tool takes advantage of the world coordinate system (WCS) keywords present in our EIS images (COE-projection) and displays celestial coordinates at each cursor position. If you want to use this feature you need to make sure that SkyCat is installed in your system.

Then, to use SkyCat as a viewer for FITS files please add the following line to your $HOME/.mailcap file:

application/x-fits; skycat -fits %s

Summary of EIS-server output options

Download as FITS file with WCS keywords: The image will be saved on your local disk.
MIME type: application/octet-stream
Download as gzip compressed FITS with WCS keywords: The image will be saved compressed on your local disk.
MIME type: application/octet-stream
Display as FITS file with WCS keywords: A FITS viewer will be started on your computer to display the image.
MIME type: application/x-fits