A number of example "virtual telescopes" have been implemented ...

Visualising hydro simulations of galaxy clusters

As a first approach towards more comprehensive virtual telescope services, GAVO makes available two services supplied by Klaus Dolag and coworkers for creating representations of the results of hydrodynamical simulations of galaxy clusters. The goal of this exercise is partly to investigate how a more realistic virtual telescope could be exposed, but also already to enable researchers to extract information from simulations that can be directly compared to the post-processed rewsults of X-Ray observations. To that end a science project has started in which the results of the physical visualisation are analysed in the same way as post-processed observations were in Schuecker et al (2004).

References:

  • Schuecker, P.; Finoguenov, A.; Miniati, F.; B�hringer, H.; Briel, U. G.
    Probing turbulence in the Coma galaxy cluster
    Astronomy and Astrophysics, v.426, p.387-397 (2004)

Planck Satellite Pipeline Simulator

Some of the most important questions in modern science include

  • how did the Universe begin,
  • how did it evolve to the state we observe today,
  • and how will it continue to evolve in the future?

The European Space Agency's (ESA's) satellite mission Planck will help to provide the answers. Planck's objective is to analyse, with the highest accuracy ever achieved, the remnants of the radiation that filled the Universe immediately after the Big Bang, which we observe today as the Cosmic Microwave Background (`CMB).

The Planck mission will collect and characterise radiation from the CMB using sensitive receivers operating at extremely low temperatures. These measurements will be used to produce the best ever maps of variations in the CMB radiation field, covering at least 95% of the sky over a wide frequency range (~30 GHz - 1 THz), and with the ability to resolve features with angular sizes of 10 arcminutes or greater at a sensitivity of one part in a million. The simultaneous mapping of the sky at a wide range of frequencies will enable the separation of the primordial cosmological background signal from foreground radiation due to our own Galaxy or extragalactic sources. This constitutes a vastly improved performance compared to balloon-borne and ground-based experiments and will exceed the performance of other space-based instruments.

An Ariane-5 launcher will carry Planck into space in 2007 to an operational orbit located some 1.5 million kilometres away from the Earth in a direction diametrically opposite the Sun (the second Lagrange point of the Sun-Earth system, L2). Planck has a nominal operational lifetime of twenty-one months.

The MPA Planck Analysis Centre (MPAC), as part of its responsibilities to the Planck project, has produced a detailed end-to-end simulation package by integrating various software modules provided by the Planck scientific community. These modules allow the generation of data which mimics in great detail the observation strategy of the Planck satellite and subsequent data processing to convert detector measurements into sky maps for scientific analysis.

The web-based tool provided here affords easy access to a simplified version of the Planck simulation pipeline. Users are able to build realistic pictures of the CMB sky as it will be observed by Planck. Although the instrumental parameters are somewhat idealised, their basic properties are very close to those expected from the real detectors. One may study how the distribution of temperature variations changes as the cosmological parameters are modified. The ability to add to the cosmological simulation our best estimates of foregrounds due to local astrophysical sources provides an understanding for the necessity to clean the maps of this contamination.

This project is a joint undertaking by MPAC and the German Astrophysical Virtual Observatory (GAVO). By the time that Planck data is delivered to the astronomical community, the need to provide access to both data and useful analysis services with community-wide standards and access protocols will be mandatory. The Virtual Observatory community is seeking to provide such standards. The tool provided here is a particular case-study in the manner by which to publish sophisticated theoretical algorithm to the larger astronomical community.

The button below opens the Planck simulator webservice.