Analysis and characterization of thermal systematic effects on the PLANCK LFI dataTanja Petrushevska
, 2010, magistrsko delo
Opis: The cosmic microwave background radiation discovered by Penzias and Wilson in 1965, is considered one of the most important experimental evidences in favour of the Hot Big Bang standard cosmological model. This radiation provides an image of the Universe when it was about 380,000 years old and has a blackbody spectral distribution at temperature T=2.725±0.002 K, index of thermodynamic equilibrium with the mater in epoch when it was released. The cosmic background radiation presents anisotropies at level of 10 5 which provide valuable information about the origin and the evolution of the Universe.
After the discovery of background radiation, tens of experiments have been performed to measure this radiation and its anisotropies. In 1992 the COBE satellite revolutionized cosmology by detecting temperature anisotropies for the first time. Launched on May 14, 2009, Planck is a European Space Agency mission designed to measure the CMB anisotropies with an accuracy set by fundamental astrophysical limits. To do this, Planck is imaging the whole sky with an unprecedented combination of sensitivity ( ΔT/T~2*10^-6), angular resolution (to 5’), and 9 frequency coverage (30 857 GHz). To reach these ambitious requirements, Planck uses an active cryogenic thermal system which cools the instruments to 0.1 K. The high sensitivity of the instrument and the cryogenic system makes the thermal systematic effects study of crucial importance to the scientific success.
The thesis is divided into six chapters:
1. Chapter 1 explains the properties of the cosmic background radiation and its anisotropies;
2. Chapter 2 presents a short overview of the various experiments dedicated to the study of cosmic background radiation;
3. Chapter 3 describes the Planck mission, its instruments and its goals, in
particular the Low Frequency Instrument (LFI) and its thermal structure;
Chapter 4 discusses the analysis of the LFI thermal stability. This work was carried out in the Physics department at the University of Trieste, at the LFI Data Processing Centre located at INAF (Instituto Nazionale di AstroFisica) - OATS (Astronomical Observatory of Trieste);
Chapter 5 presents the results of this analysis;
in Chapter 6 conclusions are drawn and proposals for future work are discussed.
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Povzetek najdenega: ...The cosmic microwave background radiation discovered by Penzias and...
Ključne besede: Cosmic background radiation, CMB, Planck, satellite mission
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