Virtual Observatory activities in the AMIGA group

Astrophysics and Space Science, 2004

Given the high cost of modern astronomical observing facilities it is evident that efforts must be made to optimally exploit the data in order to maximize the return on investment. This concept was first implemented on a large scale for the Hubble Space Telescope, and has since been taken over for other space borne and large ground-based facilities. The European HST Science Data Archive is located at the European Southern Observatory (ESO). It has been extended to include data from ESO telescopes and instruments, especially the Very Large Telescope (VLT) and Wide Field Imager (WFI). It was thus natural to design the archive such that queries could be extended across its full content, regardless of the origin of the data. This constituted a first step toward a virtual observatory. The Astrovirtel program, first established in 1999–2000 with funding provided by the European Commission, makes it possible for scientists to use this facility for their investigations. At the same time it allowed us to establish science requirements for archive cross queries, and to define capabilities required for VO's. Recently the European Commission decided to provide the funding for the implementation of the Astrophysical Virtual Observatory (AVO). This will include several European observatories and scientific organizations. It is being developed in close coordination with the US National Virtual Observatory.

Proceedings of the International Astronomical Union, 2010

In 2002 the International Virtual Observatory Alliance (IVOA) has been created in order to gather efforts on data standardization and dissemination. Since then, the virtual Observatory allowed to spread validated data all over the world and to use data from everywhere from earth. From the standards definitions to development of tools, developers have set up a technical infrastructure used by astronomers to easily search for data and make science with all available products, more tools and more confidence on the quality of data. The goal of this review is to present the state of the art of the VO data, standards and tools. This review focuses on basic astronomer's questions : what kind of data are accessible, how to deal with these data and how to use them.

2009

The OPTICON working group 3.6 in collaboration with international partners and in coordination with the Virtual Observatory, has already identified the high level requirements and the main architectural concepts for a future software environment for astronomical data reduction and analysis (Future Astronomical Software Environment). A special attention has been payed to: a) scalability, to allow the reduction of huge data volumes exploiting the hardware and software parallel architecture, b) interoperability, in order to guarantee the interaction between software coming from different sources and make easy the access to the Virtual Observatory, c) and modularity, to separate the adopted software technology from the specific computational algorithm and allow an independent evolution of the two areas. The proposed concepts have been widely discussed and shared by the astronomical community; however a lot of work still remains to do, mainly: a) the definition of open standards, b) the verification of such standards thanks to at least one reference implementation and practical user cases, c) and the whole must be supported at least by the major international organizations that develop data reduction and analysis software. All this work has led up to the definition of a new proposal for FP7 within OPTICON (where ESO, INAF, LAM-OAMP and NRAO/NVO are actively involved) which we present describing the project in detail and adding a description of the European FASE prototype, developed by INAF-IASF Milano in collaboration with LAM-OAMP (Marseille).

voparis-twiki.obspm.fr

2010

Access to astronomical data through archives and VO is essential but does not solve all problems. Availability of appropriate software for analyzing the data is often equally important for the efficiency with which a researcher can publish results. A number of legacy systems (e.g. IRAF, MIDAS, Starlink, AIPS, Gipsy), as well as others now coming online are available but have very different user interfaces and may no longer be fully supported. Users may need multiple systems or stand-alone packages to complete the full analysis which introduces significant overhead. The OPTICON Network on 'Future Astronomical Software Environments' and the USVAO have discussed these issues and have outlined a general architectural concept that solves many of the current problems in accessing software packages. It foresees a layered structure with clear separation of astronomical code and IT infrastructure. By relying on modern IT concepts for messaging and distributed execution, it provides full scalability from desktops to clusters of computers. A generic parameter passing mechanism and common interfaces will offer easy access to a wide range of astronomical software, including legacy packages, through a single scripting language such as Python. A prototype based upon a proposed standard architecture is being developed as a proof-ofconcept. It will be followed by definition of standard interfaces as well as a reference implementation which can be evaluated by the user community. For the long-term success of such an environment, stable interface specifications and adoption by major astronomical institutions as well as a reasonable level of support for the infrastructure are mandatory. Development and maintenance of astronomical packages would follow an open-source, Internet concept.

2008

Virtual observatory could be defined as a collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. Several countries have initiated national virtual observatory programs that combine existing databases from ground-based and orbiting observatories, scientific facility especially equipped to detect and record naturally occurring scientific phenomena. As a result, data from all the world's major observatories will be available to all users and to the public. This is significant not only because of the immense volume of astronomical data but also because the data on stars and galaxies has been compiled from observations in a variety of wavelengths -optical, radio, infrared, gamma ray, X-ray and more. In a virtual observatory environment, all of this data is integrated so that it can be synthesized and used in a given study. During the autumn of the 2001 (26.09.2001) six organizations from Europe put the establishment of the Astronomical Virtual Observatory (AVO) -ESO, ESA, Astrogrid, CDS, CNRS, Jodrell Bank . Its aims have been outlined as follows:

2008

We present a new software solution, based on Java, which allows to deploy and access astronomical catalogs in relational database form, with their associated data products. It is already used to provide the public VVDS data via VO and manage zCosmos data within the Italian COSMOS community; it is also used as the second generation Web interface to the XMM-LSS master catalog. DART (Database Access and Retrieval Tool) supplies a Web interface which allows to query catalogs, filter data by conditions on the columns values (even complex expressions), view the results and export them in private user files; it is also possible to make simple plots or retrieve the related data products. The software supports access to more than one catalog at a time (e.g. for multi-band usage) either in parallel, or as a couple linked by pre-built correlation tables, or even viewing the result of an identification among several catalogs as a single virtual table. DART has been designed as a general tool capable of accessing any collection of astronomical database tables and related products. It is highly (and easily) customizable editing simple configuration files and (for an increased flexibility specially concerning data product access) populating appropriately a few administrative database tables. It supports ConeSearch, SSA and SIA Virtual Observatory protocols. DART will be soon released to the astronomical community from the PANDORA Web site

2009

The aim of this thesis is providing a framework for the creation of radio astronomical archives, which can be directly integrated into the Virtual Observatory (VO) infrastructure. We will research and improve existing VO data models, in order to be able to accomodate radio astronomical datasets, providing more general observation data models. Furthermore, legacy radio astronomical analysis tools must be integrated with the VO. In this thesis we develop a mechanism to incorporate both open source and closed source (binary) legacy tools to the VO., by using remote computing techniques such as XML-RPC, creating a publish/subscribe messaging system with VO semantics. The amount of code to be changed is reduced to the addition of a small messaging module, leaving VO data discovery and manipulation to outside tools. As a side effect, a mechanism for dynamically discoverable function modules is provided, which can be generalised for multiple applications. This thesis is validated through the development, and VO integration, of two different radio astronomical archives, for the 70m DSS-63 antenna at Robledo de Chavela (Madrid), and the IRAM 30m dish at Pico Veleta, (Sierra Nevada, Granada), and the integration of the VO of the massa (MAdrid Simple Spectral Analysis) spectroscopic tool.

his paper reviews the most important componen ts of the national project of the Ukrainian Virtual Observatory (UkrVO). Among them, there is the establishment of a Joint Digital Archive (JDA) of observational data, which has been obtained at Ukrainian observatories since the 1890s, including an astronegative JDA (more than 200 thousand plates). Since this task requires VO oriented software, such issues as content verification software, integrity and dministration of the JDA, compliance of image formats with the IVOA standards, and photometric and astrometric calibration of images are considered as the most important directions of software development, which carried out by members of the UkrVO. The scientific projects using local data archives of the UkrVO are discussed, namely: an analysis of a long observational series of active galactic nuclei, the study of solar flares and solar active regions based on spectral observational archives, research and discovery of variable stars, and the study of stellar fields in the vicinity of gamma ray bursts. Particular attention is devoted to the CoLiTec Program that permits us to increase a number of observed solar system bodies and allows us to discover new bodies; for example, the C/2010 (Elenin) and P/2011 N01 comets were discovered using this program at the ISON-NM Observatory. The paper notes the creation of the UkrVO JDA prototype that provides access to the databases of the Main Astronomical Observatory, National Academy of Sciences of Ukraine (MAO NAS of Ukraine); Nikolaev Astronomical Observatory (NAO); and Lvov Astronomical Observatory.

2012

The Virtual Observatory (VO) is becoming the de-facto standard for astronomical data publication. However, the number of radio astronomical archives is still low in general, and even lower is the number of radio astronomical data available through the VO. In order to facilitate the building of new radio astronomical archives, easing at the same time their interoperability with VO framework, we have developed a VO-compliant data model which provides interoperable data semantics for radio data. That model, which we call the Radio Astronomical DAta Model for Single-dish (RADAMS) has been built using standards of (and recommendations from) the International Virtual Observatory Alliance (IVOA). This article describes the RADAMS and its components, including archived entities and their relationships to VO metadata. We show that by using IVOA principles and concepts, the effort needed for both the development of the archives and their VO compatibility has been lowered, and the joint development of two radio astronomical archives have been possible. We plan to adapt RADAMS to be able to deal with interferometry data in the future.