The Planck Satellite Simulator –

a Cosmological Toolbox

Scientists at the Max-Planck-Institute for Astrophysics (MPA) assembled a sophisticated simulation package to help in the study of the Cosmic Microwave Background (CMB) radiation from the Big Bang. This software is part of the support for the Planck satellite mission and is already in use for testing the prototype Planck data analysis software. After the satellite's launch, the simulation package will assist in the interpretation of the observations. A simplified version of the simulator is now available in the form of a linkPfeilExtern.gifweb service from the German Astrophysical Virtual Observatory (GAVO), and may be used as a tool for cosmological research and education.

Simulated maps of the Cosmic Microwave Background at all frequencies of the Planck satellite (30-1000 GHz)

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 linkPfeilExtern.gifEuropean 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 remnant radiation that filled the Universe immediately after the Big Bang, which we observe today as the Cosmic Microwave Background (CMB). Tiny variations in the temperature of the CMB over the sky can be studied to provide accurate information about the size, age, and geometry of the Universe.

The Planck mission, scheduled for launch in 2007, will collect and characterise radiation from the CMB using sensitive receivers operating at extremely low temperatures. The receivers are able to measure temperature variations of a few millionths of a degree around the average CMB temperature of roughly 2.7 Kelvin. 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). 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 both our own Galaxy and 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.

The linkPfeilExtern.gifMPA 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 collaboration and the CMB scientific community. These modules allow the generation of data which mimic in great detail the observation strategy of the Planck satellite and subsequent data processing to convert detector measurements into sky maps for scientific analysis. This allows the testing and optimisation of the data analysis software even before the satellite's launch, and can provide an estimate of the accuracy of the reconstructed CMB signal and extracted cosmological information given the instrumental noise and astrophysical foreground contamination.

The available linkPfeilExtern.gifweb-based simulation tool allows 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, and study how the distribution of temperature variations changes as the cosmological parameters are modified. The web-service serves educational and scientific applications. This project is a joint undertaking by linkPfeilExtern.gifMPAC and the linkPfeilExtern.gifGerman Astrophysical Virtual Observatory (GAVO).