Dense Sampling and Large Volume: The Structure of the Intergalactic Medium from 50,000 SDSS3 BOSS Quasar Absorption Spectra

Rupert A. Croft , E. Arnau , E. Aubourg (1) , S. Bailey , J. Bechtold , V. Bhardwaj , A. Bolton , A. Borde , J. Brinkmann , N.G. Busca (2) , W. Carithers , R. Cen , R. Charlassier (3) , M. Cortes , A. Dall'Aglio , S. Cristiani , K. Dawson , T. Delubac , A. Font-Ribera , J.-C. Hamilton (2) , S. Ho , K. Lee , J. Legoff , D. Kirkby , B. Lundgren , B. Menard , J. Miralda-Escude , N. Palanque-Delabrouille (3) , A. Myers , I. Paris (4) , S. Peirani (4) , P. Petitjean (4) , M. Pieri , J. Rich (3) , E. Rollinde (4) , N. Ross , D. Schlegel , R. Skibba , A. Slosar , N. Suzuki , H. Trac , S. Vikas , M. Viel , D. Wake , D. Weinberg , M. White , C. Yeche (3)

1 APC - Cosmologie
2 APC (UMR_7164) - AstroParticule et Cosmologie
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 IAP - Institut d'Astrophysique de Paris

The BOSS quasar spectra analyzed so far contain over a quarter billion pixels of information on the intervening intergalactic medium. The statistical power of BOSS has previously enabled 10% of the eventual full dataset to yield the first measurements of three dimensional large-scale structure in the Lya forest (Slosar et al 2011). Here we present results from a sample several times larger, covering several topics in cosmology and intergalactic medium science which are qualitatively transformed by the dense sampling (20 quasars per square degree) and enormous sky area. These include new constraints on cosmology and the neutrino mass from a Lya forest power spectrum measurement using 20 times more spectra than the largest previously published analysis (from SDSS), a new catalog of metal absorbers and a stacking analysis which has uncovered many metal species never before seen in the intergalactic medium. Cross-correlations of quasars, galaxies, metal lines and Lyman series absorption provide us with a wide variety of probes, including of cosmology, quasar host masses, lifetimes, and absorber galaxy masses. We show several of these results. We also show through correlation function analysis that the prime task, of making a BAO detection from Lya forest clustering, (the first BAO constraint between z=1 and the CMB) is well on the way to completion.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]

Rupert A. Croft, E. Arnau, E. Aubourg, S. Bailey, J. Bechtold, et al.. Dense Sampling and Large Volume: The Structure of the Intergalactic Medium from 50,000 SDSS3 BOSS Quasar Absorption Spectra. AAS 219th Meeting, Jan 2012, Austin (Texas), United States. pp.324.03. ⟨in2p3-00706848⟩