individual astronomical sources.
Spectroscopic and imaging data are available from 7 widely-used instruments;
individual astronomical
sources;
sources, mostly galactic. EUVE was active through
January 2001;
|
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Дата изменения: Tue May 29 20:01:03 2001 Дата индексирования: Tue Oct 2 05:49:43 2012 Кодировка: |
The Multimission Archive at the Space Telescope Science Institute (MAST) is NASA's optical/UV science archive center. MAST, established in October 1997, builds upon the infrastructure developed for the Hubble Space Telescope archive but expands this service to support nine additional missions (see below).
Our data holdings include eight space-based missions, three of which (HST, EUVE, and FUSE) are currently active as of January 2001. We also provide archival services for two ground-based sky surveys: the Digitized Sky Survey and the VLA 20cm radio survey known as FIRST. The combined MAST data volume exceeds 12TB, making it one of the most significant astronomical collections available on-line today. All MAST data can be accessed at the MAST home page.
The scientific value of MAST comes, in part, from the rich and varied astrophysical phenomena that dominate the optical/UV regions of the electromagnetic spectrum and from the convenient and user-friendly implementation of our World Wide Web (WWW) archive interface. The utility of the MAST supported missions is demonstrated by the scientific literature publication rate of well over 1000 papers per year which make substantial use of these data.
individual astronomical sources.
Spectroscopic and imaging data are available from 7 widely-used instruments;
individual astronomical
sources;
sources, mostly galactic. EUVE was active through
January 2001;
|
down to a flux of
1mJy. The radio images and the source catalog, currently
entries, are available;
The MAST listings are available via a simple WWW interface. A sample search page for HST data is shown in Figure 1. Similar interfaces are available for all MAST data. Archival data may be searched by name (resolved by SIMBAD or NED), position, object category, and observation specifics (date, instrument, filters, exposure time, etc.). Previews are available for most MAST missions, allowing users to have a ``quick look'' at the data before retrieving them.
The potential use of the MAST archive is greatly increased by allowing users to search more than one mission/instrument at a time and cross-correlate the archive holdings with astronomical catalogs. Cross-correlations can be performed using the Hipparcos and Sky2000 stellar catalogs, an active galactic nuclei catalog, the Abell Galaxy Cluster catalog, and any user-supplied list of positions. MAST users can select a sample of astronomical sources based on a range of properties (e.g., redshift, magnitude, radio flux for active nuclei) and then look for the relevant entries in MAST. Work is in progress to expand this facility by using NASA's Astronomical Data Center (ADC) interface. This will allow cross-correlations to be made between MAST and any of the ADC catalogs and tables, opening up new possibilities for the exploitation of MAST data.
MAST data are linked to the scientific literature to allow users
easy access to MAST-based papers directly from our interface.
For most missions the WWW interface returns the papers based on a given
dataset/proposal. Active links are provided to the Astrophysics Data System
(ADS). We have worked with ADS to provide the complementary service, that is
links between astronomical abstracts and MAST data previews, retrieval pages,
and observation logs. Literature links to IUE, ASTRO, EUVE, BEFS, and
Copernicus papers are already in place, while more than 
of
HST-based papers have been linked with their proposal ID. Work is on-going to
complete the HST literature links and to provide the same service for the
remaining MAST missions.
MAST will incorporate additional ultraviolet and optical data in the future, including those from the GALEX and CHIPS missions scheduled for launch in Fall 2001 and Spring 2002, respectively. Furthermore, MAST will host the science public archive of the Sloan Digital Sky Survey (SDSS) and the new version of the Guide Star Catalog (GSC-II). The SDSS will map in detail one-quarter of the entire sky, providing images for more than 100 million sources and redshifts for more than a million galaxies and quasars. GSC-II will include proper motion and color information, in addition to accurate coordinates, magnitudes and classification, for all objects in the sky down to at least 18th magnitude, an estimated 2 billion sources. MAST will further enhance the scientific value of its data holdings by archiving Mosaic Imager data from the National Optical Astronomy Observatories. To fully exploit the multiwavelength parameter space, which is being made available also by the many large surveys completed and under way, MAST will establish closer ties and coordination with other archive centers. MAST will work towards providing the community with science-ready products. This will include data characterization and catalogs of selected HST imaging data, thus enabling the identification of faint optical counterparts at various wavelengths, ``on-the-fly'' co-added spectra/images for objects with multiple exposures, and combined spectra spanning detector and mission boundaries.
