ESO Archive Frequently Asked Questions

General: How can I display the 9 Gb fits files of the stacked UltraVISTA images?


You must have a 64 bit OS to display the images. It will work right away in ds9 if your machine has at least 9 GByte of RAM. If not, you can choose to cut the image and open only the section you are interested in, by making use the cut-out service offered via the Science Portal.
Alternatively, you can use imcopy in IRAF, the Cutout2D utility in Python (from astropy.nddata.utils import Cutout2D), or the stand-alone utility fitscopy that comes with CFITSIO. Compiling fitscopy is usually as simple as:
make fitscopy
You can then copy out a subsection e.g. as 
fitscopy 'filename.fits[6317:42736,7063:37182]' filename.trim.fits This particular subsection would be about 4 Gbyte (and requires about 4 Gbyte RAM to make); you can of course try something smaller. The format of the subsection is x1:x2,y1:y2 (just like in IRAF).