XENON: a 1 tonne Liquid Xenon Experiment for a Sensitive Dark Matter Search

XEphem: Interactive Astronomical Ephemeris

XEUS (X-ray Evolving Universe Spectroscopy Mission)

XEUS - The X-ray Evolving Universe Spectroscopy Mission

XHIP-II: Clusters and associations

XHIP: An Extended Hipparcos Compilation

XIAO: a soft X-ray telescope for the SVOM Mission

XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources

XID: Cross-Association of ROSAT/Bright Source Catalog X-ray Sources with USNO A2 Optical Point Sources

XIM: A virtual X-ray observatory for hydrodynamic simulations

XMASS

XMM - Newton observations of Markarian 421

XMM -Newton observations of merging clusters of galaxies: A3921 and A1750

XMM and Chandra measurements of the AGN intrinsic absorption: dependence on luminosity and redshift

XMM Cluster Survey: X-ray source identification using the Sloan Digital Sky Survey

XMM detection of the supernova remnant G337.2+0.1

XMM Follow-Up Observations of Three Swift BAT-Selected Active Galactic Nuclei

XMM observation of 1RXS J180431.1-273932: a new M-type X-ray binary with a 494 s-pulse period neutron star?

XMM observation of M~87 II. Abundance structure of the interstellar and intergalactic medium

XMM Observation of N LMC 1995, a bright supersoft X-ray source