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Christian, D., Abney, F., Comeau, T., Hanisch, R. J., Harrison, J., Imhoff, C., Kidwell, R., Kimball, T., Levay, K., Padovani, P., Postman, M., Richon, J., Smith, M., & Thompson, R. 1999, in ASP Conf. Ser., Vol. 172, Astronomical Data Analysis Software and Systems VIII, eds. D. M. Mehringer, R. L. Plante, & D. A. Roberts (San Francisco: ASP), 233
The Multimission Archive at Space Telescope
Damian Christian, Faith Abney, Thomas Comeau, Robert Hanisch, Jill Harrison, Catherine Imhoff, Richard Kidwell, Timothy Kimball, Karen Levay, Paolo Padovani, Marc Postman, Joel Richon, Myron Smith, Randall Thompson
Space Telescope Science Institute, Baltimore MD, 21218
Abstract:
We present an overview of the recently created Multimission Archive at
Space Telescope (MAST). The Hubble Data Archive has expanded to
provide easy access to non-HST data sets. MAST includes
the following: the International Ultraviolet Explorer (IUE),
the Extreme Ultraviolet Explorer (EUVE), Copernicus (OAO-3), ASTRO
HUT, WUPPE and UIT data sets, and VLA FIRST data. The Digitized
Sky survey is also accessible through MAST. Data from the Far Ultraviolet
Spectroscopic Explorer (FUSE) currently scheduled for launch in early
1999, ORFEUS 1 & 2 EUV spectrometer data, and Voyager-1,2 UVS data will be
added in the near future. Two 480-platter Plasmon CD-ROM
jukeboxes provide data storage and easy access to the MAST
data. Data hierarchy, ingest and retrievals, plans for expansion, and
features of the web interface are also presented. Users can access data via
a WWW interface at
http://archive.stsci.edu/mast.html.
The Space Telescope Science Institute (STScI) holds the Hubble Data
Archive (HDA), which includes all Hubble Space Telescope (HST)
observations. As of November 1998, the HDA contains over 5.8
Terabytes of science and engineering data representing over
250,000 exposures of more than 20,000 targets. In the past few
months the volume of archived data has reached average rates of about
4-5 GB/day, with an average of 20 GB/day retrieved by
archive users.
The STScI archive recently expanded by providing access to non-HST
data sets. STScI was chosen as one of three major science archive
research centers created to provide users with easy access to archival
data. The Multimission Archive at Space Telescope (MAST) focuses on
the optical, UV and near-IR wavelength ranges, and complements the
High Energy Astrophysics Science
Archive Research Center (HEASARC) at GSFC
and the Infrared Science Archive (ISRA) at IPAC.
MAST data sets include extreme ultraviolet, ultraviolet, and selected
radio data sets listed below. These data sets may be accessed at the
MAST
homepage
and include:
- International Ultraviolet Explorer (IUE)
- Contains over 104,000 spectral images of 10,000 individual
astronomical sources in the wavelength range 1200-3350 Å.
- Copernicus (OAO-3)
- Far- (900-1,560 Å) and near-
(1,650-3,150 Å) ultraviolet spectra of 551 objects.
- Extreme Ultraviolet Explorer (EUVE)
- Extreme UV (70-760 Å)
spectroscopic observations 400 sources, mostly galactic.
- ASTRO Missions
- Various UV data sets from the ASTRO
1 and 2 shuttle missions, including
- the Hopkins Ultraviolet Telescope (HUT)
- the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE)
- the Ultraviolet Imaging Telescope (UIT)
- Faint Images of the Radio Sky at Twenty-centimeters (FIRST)
- A 20
cm (1.4 GHz) radio survey covering over 10,000 square degrees to a
flux limit of 1 mJy. Access is provided to the radio images and the source
catalog, currently having approximately 437,000 entries.
- Digitized Sky Survey (DSS)
- Digitized photographic Sky Survey plates from
the Palomar and UK Schmidt telescopes.
The MAST resources are available via a simple WWW interface
at the URL given above. A user may choose to search a region of the
electromagentic spectrum for images or spectra, or may go directly
to the search page for a specific mission.
Archival holdings may be searched by:
- Name (with SIMBAD or NED as a name resolver)
- Position (
, 
, and radius)
- Object category
- Observation specifics: date, instrument, filters, etc.
The potential use of the MAST archive is greatly improved by allowing users
to search more than one data set at a time and to also allow the archive
holdings to be compared with astronomical catalogs.
Cross correlations can be performed using:
- The Hipparcos stellar catalog (1997, ESA SP-1200)
- The Active galactic nuclei catalog (Veron-Cetty & Veron 1996;
Padovani, Giommi, & Fiore 1997)
- The Abell galaxy cluster catalog (Abell, Corwin, & Odowin 1989)
- User supplied catalogs
Currently, most of the MAST data is available over the web and
selected data sets can be quickly down-loaded. The IUE and EUVE data
sets currently reside at NSSDC and HEASARC, respectively. The IUE
data sets are currently being ingested at STScI and will be stored on
2 Plasmon CD-ROM jukeboxes. WORM media was chosen for its
cost effectiveness and ready user access. The CD-ROM option is about
50% cheaper than a DLT library, but provides enough space for the
current non-HST MAST archive and anticipated expansion. The MAST data
network consists of a SUN Enterprise 450 server, a large RAID disk
array, and 2 Plasmon 480 slot CD-ROM jukeboxes.
MAST has made every attempt to include sufficient documentation and
background information to make data products as useful as possible.
The MAST holdings for specific missions
generally include:
- Project Description
- General descriptions of the mission and instrumentation.
- Data Processing
- How the data were reduced and calibrated.
- Data Description
- Documentation on data characteristics:
wavelength coverage, resolution, field of view, and anomalies.
Data uncertainties and database field descriptions.
- Data Format
- All data are in FITS (Flexible Image Transport System)
format. Documentation includes a general description of the file contents
and header information.
- Mission-specific analysis software
- IUEDAC IDL,
UIT BDR software written in C and Fortran-77,
HUT IRAF software, and
EUVE EUV1.8 IRAF software.
Additional ultraviolet and optical data sets will be incorporated into
MAST in the future, including data from the Far Ultraviolet
Spectroscopic Explorer (FUSE) currently scheduled for launch in early
1999. FUSE will cover the wavelength range of 905-1195 Å with a
resolution of 30,000. MAST will archive Voyager-1 and Voyager-2 UVS
data, which covers the 950 to 1350 Å range. MAST also anticipates
expanding its support of ground-based archiving with the addition of
data from the National Optical Astronomy Observatories Mosaic Imager.
As demonstrated by Valdes et al. in their poster at this conference,
the Mosaic Imager will perform sub-arcsec imaging of large fields of
view and perform surveys in standard photometric bands.
Acknowledgments
STScI is operated by the Association of Universities
for Research in Astronomy, Inc., under NASA contract
NAS5-26555. Support for MAST for non-HST data is provided by the NASA
Office of Space Science via grant NAG5-7584 and by other grants and
contracts.
References
Abell, G. O., Corwin, H. G., & Olowin, R. P. 1989, ApJS, 70, 1
Padovani, P., Giommi, P., & Fiore, F. 1997, Mem. Soc. Astron. It., 68, 147
Veron-Cetty, M.-P. & Veron, P. 1996, A Catalogue of
Quasars and Active Nuclei (7th ed.) (ESO Scientific Report No. 17)
© Copyright 1999 Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, California 94112, USA
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