The diverse and dynamic landscape of services provided by data archives that has recently emerged
is in stark contrast with the classical idea of astronomical archives as static, passive repositories whose
only goal is to capture, record and preserve forever the assets produced by their observatories. In this
new scenario, archives occupy a central role as engines and enablers of the success of the astronomical
facilities they support in multiple ways. More specifically, in the case of mature missions and established observatories
that have collected large amount of data, archives can be considered new instruments in the own right as they, by favoring re-use
and new uses of single or aggregated archival datasets, promote the investigation of regions of the observational
parameter space that can otherwise be impractical to access or inaccessible altogether. In this contribution, I
will describe how the Chandra Data Archive (CDA) contributes to the final science return of the Chandra mission by
focusing on four different areas: maximization of the observational efficiency through contributions to
smooth operations of the observatory; collection and curation of a comprehensive mission bibliography;
assessment of the scientific impact of the mission by the development of specific metrics; promotion of use of
archival data across different astronomical communities. Finally, using the Chandra archive as an example,
I will briefly discuss the changes to the roles and priorities of an astronomical archive that are necessary to
adjust to the evolving needs of the mission and its constituencies.
This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical
Observatory for operation of the Chandra X-ray Center.
The Chandra Source Catalog, presently being developed by the Chandra X-ray Center, will be the definitive catalog of
all X-ray sources detected by the Chandra X-ray Observatory. The catalog interface will provide users with a simple
mechanism to perform advanced queries on the data content of the archival holdings on a source-by-source basis for
X-ray sources matching user-specified search criteria, and is intended to satisfy the needs of a broad-based group of
scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime.
For each detected X-ray source, the catalog will record commonly tabulated quantities that can be queried, including
source position, dimensions, multi-band fluxes, hardness ratios, and variability statistics, derived from all of the
observations that include the source within the field of view. However, in addition to these traditional catalog elements,
for each X-ray source the catalog will include an extensive set of file-based data products that can be manipulated
interactively by the catalog user, including source images, event lists, light curves, and spectra from each observation in
which a source is detected.
In this paper, we emphasize the design and development of the Chandra Source Catalog. We describe the evaluation
process used to plan the data content of the catalog, and the selection of the tabular properties and file-based data
products to be provided to the user. We discuss our approach for managing catalog updates derived from either
additional data from new observations or from improvements to calibrations and/or analysis algorithms.
KEYWORDS: Databases, Data archive systems, Observatories, Space operations, Data storage, X-rays, Human-machine interfaces, Data processing, Astronomy, Interfaces
We present a discussion of the lessons learned from establishing and operating the Chandra Data Archive (CDA). We offer an overview of the archive, what preparations were done before launch, the transition to operations, actual operations, and some of the unexpected developments that had to be addressed in running the archive.
From this experience we highlight some of the important issues that need to be addressed in the creation and running of an archive for a major project. Among these are the importance of data format standards; the integration of the archive with the rest of the mission; requirements throughout all phases of the mission; operational requirements; what to expect at launch; the user interfaces; how to anticipate new tasks; and overall importance of team management and organization.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.