Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.adass.org/adass/proceedings/adass94/mcdonaldk.ps Äàòà èçìåíåíèÿ: Tue Jun 13 20:50:33 1995 Äàòà èíäåêñèðîâàíèÿ: Tue Oct 2 03:12:07 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: cygnus

Astronomical Data Analysis Software and Systems IV
ASP Conference Series, Vol. 77, 1995
R. A. Shaw, H. E. Payne, and J. J. E. Hayes, eds.
The World Wide Web: Cornerstone of the EUVE Science
Archive
K. McDonald, B. Stroozas, B. Antia, B. Roberts, K. Chen, N. Craig,
and C. Christian
Center for EUV Astrophysics, University of California 2150 Kittredge
Street, Berkeley, CA 94720--5030
Abstract. The Science Archive for the Extreme Ultraviolet Explorer
(EUVE) satellite is using the World Wide Web (WWW) client/server
software model as the cornerstone for the dissemination of EUVE archival
material. A number of on­line services are available for accessing the
large amounts of EUVE data that have been released publicly in the past
year; additional services provide access to EUVE­related software and
information. This paper outlines the current Archive WWW services
and discusses plans for the future.
1. EUVE and the Science Archive
NASA's Extreme Ultraviolet Explorer (EUVE) satellite was launched on 1992
June 7. In the more than two years since, EUVE has performed exceedingly
well, obtaining hundreds of gigabytes of scientifically invaluable data, which
researchers will continue to analyze for years to come. Among the exciting early
scientific results are the first complete EUV all­sky survey, the first EUV images
of extended objects (e.g., the Moon, the Vela and Cygnus supernova remnants,
and the Jupiter­Io plasma torus), and the first detection of helium on Mars.
The EUVE Science Archive at the Center for EUV Astrophysics (CEA) at
the University of California, Berkeley, has been established to efficiently archive
and disseminate to the public the large amounts of EUVE data and its asso­
ciated software and documentation. The Archive has been actively working to
implement innovative ideas and technologies, building the infrastructure to store
and provide easy access to EUVE archival material. One such innovative idea
is the use of the World Wide Web (WWW).
2. EUVE Science Archive WWW Services
The WWW provides a simple, fast, efficient, and user­ and developer­friendly
environment for the global dissemination of EUVE archival material. The CEA
WWW site 1 offers a variety of Archive services for EUVE data, software, doc­
umentation, and general information, as detailed in the following sections.
1 http://www.cea.berkeley.edu/HomePage.html
1

2
2.1. Data Services
One of the major functions of the Archive is to provide researchers with access
to EUVE data. Proprietary data rights for EUVE observations began to expire
in early 1994. In 1994 August, the data from the survey phase of the mission
was released on the WWW via the following services:
ffl catalogs --- In cooperation with NASA's Astrophysics Data System (ADS)
project, the EUVE source catalogs (Malina et al. 1994; Bowyer et al. 1994;
McDonald et al. 1994) have been installed in the new ADS WWW catalog
service. This service provides users with immediate access to published
scientific results on over 400 confirmed EUVE sources.
ffl source count rates --- The EUVE Count Rate Service is a form­based ser­
vice that analyzes the survey skymaps to search for any significant source
detections near an input location. The count rate information for such
detections are returned via e­mail to the user within hours of the request.
ffl skymaps --- The EUVE Skymap Request Service is a form­based service
that allows users to request small sections of the EUVE survey skymaps.
After some initial processing based on the full skymaps at CEA, the re­
quester is notified via e­mail within hours of the request that the FITS
format skymap sections are available for pick­up in the CEA anonymous
ftp site.
ffl ``pigeonholes'' --- An EUVE pigeonhole is a file that contains the time­
tagged information for photons within a small radius of a given position
on the sky. The EUVE Pigeonhole Request Service is a form­based ser­
vice that allows users to request EUVE pigeonholes. As with the skymaps
above, the requester is notified via e­mail within a day or two of the re­
quest when the FITS Bintable format pigeonholes are available for pick­up
in the CEA ftp site. This service is innovative in that the requester is actu­
ally remotely accessing the raw EUVE telemetry and invoking the required
processing to create the pigeonhole data products .
ffl calibration data --- In order to properly analyze EUVE pigeonholes, re­
searchers require some supporting calibration data: instrument effective
areas, vignetting maps, and point­spread functions, all of which are avail­
able on­line as FITS format files.
The proprietary data rights for the individual guest observer (GO) observa­
tions began to expire in 1994 April; additional data sets continue to be released
on a monthly basis. Since the GO data sets typically require hundreds of MB of
disk space to process and analyze, the Archive has developed the EUVE Spectral
Data Browser service that allows users to browse, preview, and retrieve the pub­
lic one­dimensional spectra. The spectral browser provides search capabilities
(e.g., search by position and/or source classification) that enhance the usability
of the browser by helping researchers quickly and easily locate those sources that
match their particular interests. For those researchers requiring additional data
for these observations (e.g., images, QPOE files, and telemetry tables), the full
GO data sets may be ordered via WWW forms and are delivered on magnetic
tape via postal mail.

3
Work is in progress to provide a variety of additional services including
a complete standard set of skymap images, a standard set of pigeonholes for
cataloged sources, more complete on­line access to the GO data sets (e.g., images
and telemetry tables), and access to long­exposure imaging observations from
the EUVE Right Angle Program (RAP---those observations taken concurrently
during GO observations using the ``scanning'' telescopes, which are mounted at
right angles to the GO spectrometers). Analysis services (e.g., light curves from
pigeonhole data) are also under development.
2.2. Software Services
In addition to providing EUVE data, the Archive is committed to implementing
various software services to complement the available data. The long­term goal
is to serve as a ``clearing­house'' for software contributed by external users to
support EUV­related research. Toward that end, the following tools are cur­
rently available:
ffl ISM transmission --- Based on the model of Rumph, Bowyer, & Vennes
(1994), this tool calculates the transmission of the interstellar medium
(ISM) at EUV wavelengths.
ffl neutral hydrogen column density --- Based on the published data of Frus­
cione et al. (1994) and Diplas & Savage (1994), this tool returns a table
of neutral hydrogen (H i) column density information for the ten sources
nearest to a given position.
ffl optically thin plasma spectra --- This tool applies the Landini­Fossi X­
ray/EUV spectral code (Landini & Fossi 1990) to create a spectrum for a
specified emission measure, stellar distance, and interstellar H i, He i, and
He ii column density.
As this pool of unique utilities grows with contributions from the astronom­
ical community, it will serve as a shared resource of useful software tools for
researchers, fostering cooperation and enhancing the scientific return from the
EUVE mission.
2.3. Information Services
A wide variety of documentation and information is also available to round out
the public EUVE archival material. This material includes (1) general infor­
mation on EUVE , CEA, and the Archive, (2) CEA publications, including the
EUVE bibliography, journal and conference abstracts and papers, the special
EUVE edition of the Journal of the British Interplanetary Society (JBIS, 1993),
and past editions of the EUVE electronic newsletter, and (3) form­based ser­
vices for such activities as ordering EUVE CD­ROMs and archival data sets
or for contacting Archive personnel. Examples of some of the information ser­
vices under development include a ``meta­index'' for the Archive and a Guest
Investigator (GI) Program. The Archive meta­index will fully describe and
link together all the public EUVE and associated data (e.g., finding charts and
spectra from the optical identification program), providing an efficient and easy­
to­use database containing all the available information for EUVE sources. The

4
GI program is being implemented to provide data analysis services to the re­
search community by offering a standard package of support (e.g., computer
access and scientific/technical personnel) to assist researchers in exploring the
scientific potential of the EUVE data sets.
3. Summary
The EUVE Science Archive is using the WWW as the cornerstone for dissem­
inating EUVE archival material. A wide variety of on­line electronic services
provide access to large amounts of public EUVE data as well as to related soft­
ware and information. As the project continues to mature, additional WWW
services will be made available in order to assist the research community with the
efficient and maximal use of EUVE data. For additional information, contact
the Archive at the following address:
EUVE Science Archive
Center for EUV Astrophysics, University of California
2150 Kittredge Street, Berkeley, CA 94720--5030
510--642--3032 (voice) or 510--643--5660 (fax)
archive@cea.berkeley.edu
http://www.cea.berkeley.edu
Acknowledgments. The authors would like to thank Prof. Stuart Bowyer,
Dr. Roger F. Malina, and the EUVE science team for their general support.
Special thanks go to Bill Boyd and Steve Chan for their assistance in the Archive
WWW efforts. This work has been supported by NASA contract NAS5--29298.
References
Bowyer, S., Lieu, R., Lampton, M., Lewis, J., Wu, X., Drake, J. J., & Malina,
R. F. 1994, ApJS, 93, 569
Diplas, A., & Savage, B. D. 1994, ApJS, 93, 211
Fruscione, A., Hawkins, I., Jelinsky, P., & Wiercigroch, A. 1994, ApJS, 94, 127
JBIS 1993, Journal of the British Interplanetary Society, 46
Landini, M., & Monsignori Fossi, B. C. 1990, A&AS, 82, 229
Malina, R. F., Marshall, H. L., Antia, B., Christian, C. A., & Dobson, C. A.
1994, AJ, 107, 751
McDonald, K., Craig, N., Sirk, M. M., Drake, J. J., Fruscione, A., Vallerga,
J. V., & Malina, R. F. 1994, AJ, 108, 1843
Rumph, T., Bowyer, S., & Vennes, S. 1994, AJ, 107, 2108