No Arabic abstract
In the Virtual Observatory (VO), the Registry provides the mechanism with which users and applications discover and select resources -- typically, data and services -- that are relevant for a particular scientific problem. Even though the VO adopted technologies in particular from the bibliographic community where available, building the Registry system involved a major standardisation effort, involving about a dozen interdependent standard texts. This paper discusses the server-side aspects of the standards and their application, as regards the functional components (registries), the resource records in both format and content, the exchange of resource records between registries (harvesting), as well as the creation and management of the identifiers used in the system based on the notion of authorities. Registry record authors, registry operators or even advanced users thus receive a big picture serving as a guideline through the body of relevant standard texts. To complete this picture, we also mention common usage patterns and open issues as appropriate.
The Virtual Observatory Registry is a distributed directory of information systems and other resources relevant to astronomy. To make it useful, facilities to query that directory must be provided to humans and machines alike. This article reviews the development and status of such facilities, also considering the lessons learnt from about a decade of experience with Registry interfaces. After a brief outline of the history of the standards development, it describes the use of Registry interfaces in some popular clients as well as dedicated UIs for interrogating the Registry. It continues with a thorough discussion of the design of the two most recent Registry interface standards, RegTAP on the one hand and a full-text-based interface on the other hand. The article finally lays out some of the less obvious conventions that emerged in the interaction between providers of registry records and Registry users as well as remaining challenges and current developments.
Tunka-Rex (Tunka Radio Extension) was a detector for ultra-high energy cosmic rays measuring radio emission for air showers in the frequency band of 30-80 MHz, operating in 2010s. It provided an experimental proof that sparse radio arrays can be a cost-effective technique to measure the depth of shower maximum with resolutions competitive to optical detectors. After the decommissioning of Tunka-Rex, as last phase of its lifecycle and following the FAIR (Findability - Accessibility - Interoperability - Reuse) principles, we publish the data and software under free licenses in the frame of the TRVO (Tunka-Rex Virtual Observatory), which is hosted at KIT under the partnership with the KCDC and GRADLCI projects. We present the main features of TRVO, its interface and give an overview of projects, which benefit from its open software and data.
The Virtual Observatory has reached sufficient maturity for its routine scientific exploitation by astronomers. To prove this statement, here I present a brief description of the complete VO-powered PhD thesis entitled Galactic and extragalactic research with modern surveys and the Virtual Observatory comprising 4 science cases covering various aspects of astrophysical research. These comprize: (1) homogeneous search and measurement of main physical parameters of Galactic open star clusters in huge multi-band photometric surveys; (2) study of optical-to-NIR galaxy colors using a large homogeneous dataset including spectroscopy and photometry from SDSS and UKIDSS; (3) study of faint low-mass X-ray binary population in modern observational archives; (4) search for optical counterparts of unidentified X-ray objects with large positional uncertainties in the Galactic Plane. All these projects make heavy use of the VO technologies and tools and would not be achievable without them. So refereed papers published in the frame of this thesis can undoubtedly be added to the growing list of VO-based research works.
The Tunka Radio Extension (Tunka-Rex) is a cosmic-ray detector operating since 2012. The detection principle of Tunka-Rex is based on the radio technique, which impacts data acquisition and storage. In this paper we give a first detailed overview of the concept of the Tunka-Rex Virtual Observatory (TRVO), a framework for open access to the Tunka-Rex data, which currently is under active development and testing. We describe the structure of the data, main features of the interface and possible applications of the TRVO.
In the framework of the Europlanet-RI program, a prototype of Virtual Observatory dedicated to Planetary Science was defined. Most of the activity was dedicated to the elaboration of standards to retrieve and visualize data in this field, and to provide light procedures to teams who wish to contribute with on-line data services. The architecture of this VO system and selected solutions are presented here, together with existing demonstrators.