NED is a comprehensive database of multiwavelength data for extragalactic objects, providing a systematic, ongoing fusion of information integrated from hundreds of large sky surveys and tens of thousands of research publications. The contents and services span the entire observed spectrum from gamma rays through radio frequencies. As new observations are published, they are cross- identified or statistically associated with previous data and integrated into a unified database to simplify queries and retrieval. Seamless connectivity is also provided to data in NASA astrophysics mission archives (IRSA, HEASARC, MAST), to the astrophysics literature via ADS, and to other data centers around the world.
177 million objects; 190 million multiwave-length source cross-IDs; 1.4 million object associations; 4.0 million objects with redschifts; 1,75 billion photometric measurements with SEDs; 609 million diameter measurements; 25,9 million objects linked to 84 thousand references; 2,7 million images, maps and external links; 478 thousand spectra; 72 thousand object notes; 209 thousand objects with detailed attributes; 63 thousand redshift-independent distances for 13 thousand objects
NASA/IPAC Extragalactic Database is covered by SCOPUS. NED's data and references are being continually updated, with revised versions being put on-line every 4-6 months.
NED contains "Level 5" a knowledgebase for extragalactic astronomy and cosmology