NASA/IPAC Extragalactic Database

About NED

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.

Objects can be queried By Name, Near Name or Near Position (Cone), or In Refcode. Galaxy samples can be constructed By Parameter constraints on Sky Area, Redshift, Flux Density (Magnitude), Object Types, and Survey Names, or by galaxy Classifications and Attributes, or In Reference Code. References can be queried By Author and By Object Name. The LEVEL 5 Knowledgebase augments review articles in extragalactic astrophysics and cosmology with object names and graphical content within the articles linked directly to relevant database queries. More on the usage of NED can be found at User Guides.

The database content includes a master index of distinct astrophysical objects, multiwavelength cross-identifications, associations, positions, redshifts, redshift-independent distances, photometry, diameters, images, spectra, and detailed notes. NED Holdings provides counts and graphics of the current content in NED, describes how data are integrated into NED, and also supplys explantions on NED's processing of large data sets. Derived quantities include Galactic extinction, velocity corrections, Hubble flow distances and scales, cosmological corrections, quick-look luminosities, and spectral energy distributions (SEDs).

Automated access to NED's Web services using computer programs and scripts is supported. See NED Program Interface for further information. Please adhere to the NED Guidelines for Automated Queries as NED's ability to support automated access involving large data volumes or high query rates is limited.

NED's data and references are being continually updated in an internal production database, and revised versions are released on the public website every few months. New or improved science functionality is also released on a regular basis.

Acknowledging NED

If your research benefits from the use of the NED database, the following acknowledgement in your paper would be appreciated:

This research has made use of the NASA/IPAC Extragalactic Database, which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology.

When citing NED within a paper, the following statement may be inserted as a footnote:

The NASA/IPAC Extragalactic Database (NED) is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology.