Joint Astrophysics Colloquium

How to do Cosmology with the Lyman-alpha forest

Anže Slosar

BNL

I will discuss recent results from measurements of the Lyman-alpha forest in the spectra of distant quasars by the Baryon Oscillation Spectroscopic Survey (BOSS), part of the Sloan Digital Sky Survey (SDSS-III). Our main success to date is detection of the baryon acoustic oscillation feature at z ~ 2.4 in the three-dimensional correlation function of the transmitted flux fraction. This result is derived from a sample of ~60K quasars in Data Release 9. In a striking confirmation of the standard cosmological model, the position of the baryonic peak is measured with 2% statistical and 1% systematic error and is consistent with the LCDM model. I will also show preliminary detection of the BAO in the cross-correlation between Lyman-alpha forest and quasar positions. Finally, I will mention other developments: measurement of the 1D power spectrum of flux fluctuations, first measurements of the Lyman-beta forest power spectrum and renwed efforts to simulate the intergalactic medium responsible for the forest.