Résumé / Abstract Seminaire_IAP
« La forêt Lyman alpha dans le spectre d'absorption des quasars : contraintes cosmologiques »

Emmanuel Rollinde
Institut d'Astrophysique de Paris (Paris, France)

The intergalactic medium is revealed by the numerous HI absorption lines seen in the spectra of distant quasars, the so-called Lyman-alpha forest. These lines are generally believed to arise from spatially extended density fluctuations of moderate amplitude in the continuous intergalactic medium.
The baryons thereby follow the dark matter distribution on scales larger than the Jeans length. Observations of the Lyman-alpha forest can thus be used to constrain structure formation models and cosmological parameters.
I will first summarize different methods to analyse these observations.
Results on the determination of the power spectrum and methods to constrain the cosmological constant, will then be discussed.
vendredi 3 octobre 2003 - 11:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage