ADS (Astrophysics Data System) is NASA's principal on-line research facility, and is a research tool that is intended to make access to data and information convenient and easy for the science user. The ADS uses an interface that allows its users to make queries based on a multitude of astronomical data sets that are physically located in different locations, but available for querying in a uniform way, regardless of how the data sets are organized and independent of where they are actually located. This liberates the users from learning different access methods. The ADS includes tools for data visualization once these data have been retrieved. A set of database management functions is available for manipulating the retrieved tables of objects which can be written to files in several formats, including ASCII and FITS. These formats allow data obtained via ADS to be imported into astronomical data analysis systems such as IRAF, AIPS, or MIDAS. The ADS also includes visualization tools that allow users to make 2-D plots of one table column versus another.
Registration forms to access ADS may be obtained from the ADS user support at ads@cuads.colorado.edu. Apart from access to many other services which are described separately in the present paper, the ADS Release v4.0 of January 1994, provides access to over 250 catalogs, including over 50 radio source catalogs and over 161,000 abstracts searchable with complex algorithms (also see §5. for access to abstracts via other services).
Further information about ADS is available via their WWW home page (URL http://adswww.harvard.edu/adswww/adshomepg.html). A number of ADS services are available directly through the WWW, and access through this method is typically faster, easier to use, and does not require registration. The majority of the catalogs can be accessed at URL http://adswww.harvard.edu/catalog_service.html. The ADS Abstract Service is available via the URL http://adswww.harvard.edu/abstract_service.html. Other ADS services available via the WWW are listed at URL http://adswww.harvard.edu/ads_services.html. [References: Weiss and Good (1991), Giovane (1992), Murray et al. (1992), Kurtz (1993), Kurtz et al. (1994), Eichhorn (1994).]
Update 7 Jan. 95: ApJL (Astrophysics Journal Letters) papers are available at http://adsabs.harvard.edu/article_service.html.