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
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 In 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
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
multiwavelength cross-identifications, associations, positions, redshifts,
redshift-independent distances, photometry, diameters, images, spectra, and
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
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
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
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,
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.