This website is a research tool for estimating sensitivity limit in XMM Newton data. It is an updated version of the FLIX upper limit server developed by Clive Page at the University of Leicester (


The web application is a fork of the XMM catalogue web server at IRAP which had originally benefited from the assistance of citizen scientists — highly experienced software engineers working outside the academia that volunteered to help with its development. The present web application has been updated with backend and frontend re-coded to meet the purpose of the sensitivity estimator.

Here is the list of contributors in alphabetical order:


The website is experimental and works in β mode, so some features may not work properly. If you believe you came across its malfunction, or want to request a new feature, you are welcome to email site authors.


If this website is useful for your research, please include the link and cite [...] in any emerging publication.


We would like to acknowledge the usage of these open source technologies: