José Enrique Ruiz

Web Services as Building Blocks for Science Gateways in Astrophysics

An efficient exploitation of Distributed Computing Infrastructures (DCIs) is needed to deal with the data deluge that the scientific community is facing, in particular the Astrophysics one due to the emerging Square Kilometre Array (SKA) telescope that will reach data rates in the exascale domain. Hence, Science Gateways are being enriched with advanced tools that not only enable the scientists to build their experiments but also to optimize their adaptation to different infrastructures. In this work we present a method, called “two-level workflow system”, to build this kind of tools and we apply it to a set of analysis tasks of interest for some use applications to the SKA. This method uses the Software-as-a-Service model to keep the scientists insulated from technical complexity of DCIs, and the COMPSs programming model to achieve an efficient use of the computing resources.

When History Matters - Assessing Reliability for the Reuse of Scientific Workflows

Scientific workflows play an important role in computational research as essential artifacts for communicating the methods used to produce research findings. We are witnessing a growing number of efforts that treat workflows as first-class artifacts for sharing and exchanging scientific knowledge, either as part of scholarly articles or as stand-alone objects. However, workflows are not born to be reliable, which can seriously damage their reusability and trustworthiness as knowledge exchange instruments. Scientific workflows are commonly subject to decay, which consequently undermines their reliability over their lifetime. The reliability of workflows can be notably improved by advocating scientists to preserve a minimal set of information that is essential to assist the interpretations of these workflows and hence improve their potential for reproducibility and reusability. In this paper we show how, by measuring and monitoring the completeness and stability of scientific workflows over time we are able to provide scientists with a measure of their reliability, supporting the reuse of trustworthy scientific knowledge.

Virtual Observatory Activities in the AMIGA Group

The AMIGA (Analysis of the interstellar Medium of Isolated GAlaxies) project is an international collaboration led from the Instituto de Astrofisica de Andalucia (CSIC). The group’s experience in radio astronomy databases turned, as a natural evolution, into an active participation in the development of data archives and radio astronomy software. The contributions of the group to the Virtual Observatory (VO) have been mostly oriented towards the deployment of large VO compliant databases and the development of access interfaces (IRAM 30 m Pico Veleta, DSS–63 70 m in Robledo de Chavela). We also have been working in the development of an API for VO tools that will ease access to VO registries and communication between different VO software. A collaboration with the Kapteyn Astronomical Institute has started recently in order to perform a complete renovation of the only existing high-level software (GIPSY) for the analysis of datacubes, allowing its fully integration in the VO.

Building a VO-compliant Radio Astronomical DAta Model for Single-dish radio telescopes (RADAMS)

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.

A GALAXY BASELINE: Multiwavelength Study of a Sample of the Most Isolated Galaxies in the Local Universe

We introduce and describe main results of the AMIGA project. AMIGA involves a panchromatic characterization for many of the most isolated galaxies in the local universe. Many of these galaxies have avoided major interaction events for all, or most, of their lives. Our studies show these galaxies to be the most IR/radio/optically “quiet” sample that is known. AMIGA data are publicly released under a VO interface at http://amiga.iaa.es/ and are also accessible by standard VO tools, as, e.g. TOPCAT.

A VO Archive for the DSS-63 Antenna at Robledo

In this contribution we describe the development of a Virtual Observatory (VO) Archive for the DSS-63 antenna of the NASA Deep Space Communication Complex in Robledo de Chavela (Madrid). In an initial step the archive includes observations in the K-band (18–26 GHz) of the mentioned antenna with a future extension to other ranges, in particular the Q-band (40–50 GHz) and the Ka-band (32 GHz). A first version of the archive will be available from the LAEFF Scientific Data Centre1 by the end of 2008. This work is the result of a collaboration between the AMIGA group of the IAA–CSIC and the SVO and Radioastronomy groups at LAEFF and forms part of a pioneering initiative to integrate radio astronomical data and services in the Virtual Observatory.