IVOA Newsletter - May 2014 (pdf)

Created: April 30, 2014 - 22:01 UTC

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IVOA Newsletter Editors: Mark G. Allen, Deborah Baines, Sarah Emery Bunn, Chenzou Cui, August Muench, Mark Taylor & Ivan Zolotukhin.

** The International Virtual Observatory Alliance (IVOA) was formed in June 2002 with a mission to facilitate the international coordination and collaboration necessary for the development and deployment of the tools, systems and organizational structures necessary to enable the international utilization of astronomical archives as an integrated and interoperating virtual observatory. The IVOA now comprises 20 VO programs from Argentina, Armenia, Australia, Brazil, Canada, Chile, China, Europe, France, Germany, Hungary, India, Italy, Japan, Russia, South Africa, Spain, Ukraine, the United Kingdom, and the United States and an inter-governmental organization (ESA). Membership is open to other national and international programs according to the IVOA Guidelines for Participation. You can read more about the IVOA and what we do at http://ivoa.net/about/.**

What is the VO?

The Virtual Observatory (VO) aims to provide a research environment that will open up new possibilities for scientific research based on data discovery, efficient data access, and interoperability. The vision is of global astronomy archives connected via the VO to form a multiwavelength digital sky that can be searched, visualized, and analyzed in new and innovative ways. VO projects worldwide working toward this vision are already providing science capabilities with new tools and services. This newsletter, aimed at astronomers, highlights VO tools and technologies for doing astronomy research, recent papers, and upcoming events.

IVOA news

Chilean Virtual Observatory (ChiVO) joins the IVOA

The Chilean VO, which is supported by five Chilean universities, ALMA, and the REUNA research consortium, was welcomed into the IVOA at the September 2013 IVOA meeting. ChiVO will focus on building the tools and technology infrastructure necessary for Chilean researchers to take advantage of the terabytes of data that will be produced by ALMA. More information can be found at http://www.chivo.cl/.

Moving forward with Data Standards

The past six months have seen the recommendation of three new data standards. These include a Photometry Data Model for describing photometric systems, and two specifications for data access services (Data Access Layer Interface, Describing Simple Data Access Services). The VOTable standard, which is an XML standard for the interchange of tables of data and metadata, moved to version 1.3.

VO applications and implementation highlights

Theoretical Astrophysical Observatory (TAO)

The Australian VO is happy to announce the launch of the TAO, which houses queryable data from multiple popular cosmological simulations and galaxy formation models. Results can be funnelled through higher-level modules to build custom mock galaxy catalogues and images. TAO is accessible from anywhere you can access the internet. TAO is part of the All-Sky Virtual Observatory (ASVO) and is funded and supported by Astronomy Australia Limited, the National eResearch Collaboration Tools and Resources (NeCTAR), and Swinburne University of Technology.

More Information: https://tao.asvo.org.au/tao/

VO Client Release - Access the VO from your desktop

The US Virtual Astronomical Observatory (VAO) has released VOClient - a software package that enables direct access to services in the VO from a Unix terminal or scripting environment. The VOClient command-line tools allow you to discover archives and catalogs through queries to the VAO Registry, search-for and download images, spectra, and catalogs, and interoperate with other VO-compatible tools. These tools can be used to create customized access to VO services, new VO tools or enhancements to existing software by adding VO capabilities.

More Information: http://www.usvao.org/science-tools-services/voclient/

Comet, a Python implementation of the VOEvent Transport Protocol

VOEvent is the IVOA system for describing transient celestial events. Details of transients detected by many projects, including Fermi, Swift, and the Catalina Sky Survey, are currently made available as VOEvents, and it has been selected as the standard alert format by future facilities such as LSST and SKA. Comet is an implementation of the VOEvent Transport Protocol, which makes the fast and reliable distribution of VOEvents to the community possible. Comet enables you to subscribe to real-time streams of ongoing events, to use filters to select only events relevant to your science case and to publish your own events to the global VOEvent backbone. Comet is written in Python, is open source and is freely available from http://comet.transientskp.org/.

More Information: http://comet.transientskp.org/ , https://github.com/jdswinbank/Comet

TOPCAT Visualisation

TOPCAT has recently had an overhaul of its visualisation capabilities. New features include sky axes, the ability to plot vectors, ellipses, contours and analytic functions, hybrid scatter/density plots, improved 3d navigation, better interactive response, LaTeX labelling of axes, more configurability, and better performance for large (multi-million-row) tables. As well as visualisation, TOPCAT continues to provide a wide range of other analysis capabilities for tabular data including VO access, crossmatching and row selections.

More Information: http://www.starlink.ac.uk/topcat/

CASSIS: Version 3.6.1 released

The latest release of CASSIS (Centre d’Analyse Scientifique de Spectres Instrumentaux et Synthétiques), version 3.6.1, is available for download since March 4, 2014. CASSIS provides tools to visualize and analyze spectra, in particular to perform line identification. A number of changes have been and are being implemented to make CASSIS VO-compatible. CASSIS now includes a Simple Spectral Access (SSA) module and also allows the user to interrogate the VAMDC online database (http://www.vamdc.eu/access-data/portal), rather than a local database. Both of these features are illustrated in the accompanying figure: the top panel shows a SSA query on Orion with the responses from different services being displayed in different tabs, while the bottom panel shows the display of the selected ISO-LWS spectrum, overlaid with all CO transitions found in the VAMDC/CDMS database and potentially present in the spectrum (green lines); clicking on any of these lines displays the associated spectroscopic parameters.

More Information: http://cassis.irap.omp.eu

ETC-42

ETC-42 is a Generic Exposure Time Calculator developed by CeSAM/LAM. Unlike usual existing ETCs, it can calculate the Signal to Noise Ratio (SNR) for any site and instrumentation type and perform simulations for a wide range of existing or future telescopes. It can simulate objects using theoretical spectral distributions (black bodies, flat energy flux, etc) or with user defined (or imported via SAMP) spectra. Simulation results can be saved, exported or broadcast in VOTable format. A plugin framework is also available for pre and post process of simulations. ETC-42 provides a user friendly Graphical User Interface (GUI) as well as a command line mode supporting script execution.

More Information: http://projets.oamp.fr/projects/etc

Some recent papers about VO-enabled science

A Cross-correlation Analysis of Active Galactic Nuclei and Galaxies Using Virtual Observatory: Dependence on Virial Mass of Supermassive Black Hole
Komiya, Yutaka; Shirasaki, Yuji; Ohishi, Masatoshi; Mizumoto, Yoshihiko
The Astrophysical Journal, Volume 775, Issue 1, article id. 43, 12 pp. (2_013).

We present results of the cross-correlation analysis between active galactic nuclei (AGNs) and galaxies at redshift 0.1-1. We obtain data of 10, 000 Sloan Digital Sky Survey AGNs in which their virial masses with a supermassive black hole (SMBH) were estimated. The UKIDSS galaxy samples around the AGNs were obtained using the virtual observatory. The scale length of AGN-galaxy cross-correlation for all of the samples is measured to be r_0= 5.8^{+0.8}_{-0.6},h^{-1},Mpc (for the fixed slope parameter γ = 1.8). We also derived a dependence of r0 on the BH mass, MBH, and found an indication of an increasing trend of r0 at MBH > 108 M⊙. It is suggested that the growth of SMBHs is mainly driven by interactions with the surrounding environment for MBH > 108 M⊙. On the other hand, at MBH < 108 M⊙, we did not find the BH mass dependence. This would imply that for less massive BHs, the mass growth process can be different from that for massive BHs.

Refereed Publications

All ADS links mentioning the “virtual observatory” in the abstract

All refereed publications mentioning the “virtual observatory” in the abstract

VO calendar

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