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
to the astrophysics literature via
and to other data centers around the world.
Objects can be queried
Near Name or
Near Position (cone search), and
With Unprocessed Catalog Sources
(to include very large catalog sources that are not yet cross-matched with NED objects).
Galaxy samples can be constructed
constraints on Sky Area, Redshift, Flux Density (Magnitude), Object Types, and Survey Names,
or by galaxy
Classifications and Attributes,
or By Reference Code. References can be queried
By Author and
By Object Name.
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.
For further information, see
NED for a New Era (Mazzarella et al. 2007).
Specific sample query URLs, which can be accessed via utilities such as
wget and curl or from programs
written in Perl, Python or Java, can be found in
NED VO Services (Mazzarella et al. 2008).
However, NED's ability to support automated access involving
large data volumes or high query rates is limited. Please adhere to the
NED Guidelines for Automated Queries.
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.
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 (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
When citing NED within a paper, the following statement may be inserted as a footnote:
The NASA/IPAC Extragalactic Database (NED) is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.