Using a sample of approximately 14,000 z>2.1 quasars observed in the first year of the Baryon Oscillation Spectroscopic Survey (BOSS), we measure the three-dimensional correlation function of absorption in the Lyman-alpha forest. The angle-averaged correlation function of transmitted flux (F = exp(-tau)) is securely detected out to comoving separations of 60 Mpc/h, the first detection of flux correlations across widely separated sightlines. A quadrupole distortion of the redshift-space correlation function by peculiar velocities, the signature of the gravitational instability origin of structure in the Lyman-alpha forest, is also detected at high significance. We obtain a good fit to the data assuming linear theory redshift-space distortion and linear bias of the transmitted flux, relative to the matter fluctuations of a standard LCDM cosmological model (inflationary cold dark matter with a cosmological constant). At 95% confidence, we find a linear bias parameter 0.16<b<0.24 and redshift-distortion parameter 0.44<beta<1.20, at central redshift z=2.25, with a well constrained combination b(1+\beta)=0.336 +/- 0.012. The errors on beta are asymmetric, with beta=0 excluded at over 5 sigma confidence level. The value of beta is somewhat low compared to theoretical predictions, and our tests on synthetic data suggest that it is depressed (relative to expectations for the Lyman-alpha forest alone) by the presence of high column density systems and metal line absorption. These results set the stage for cosmological parameter determinations from three-dimensional structure in the Lyman-alpha forest, including anticipated constraints on dark energy from baryon acoustic oscillations.

## ZORA Wartung

ZORA's new graphical user interface has been launched. For further infos take a look at Open Access Blog 'New Look & Feel – ZORA goes mobile'.

Slosar, A; Font-Ribera, A; Pieri, M M; Rich, J; Le Goff, J M; Aubourg, É; Brinkmann, J; Busca, N; Carithers, B; Charlassier, R; Cortês, M; Croft, R; Dawson, K S; Eisenstein, D; Hamilton, J C; Ho, S; Lee, K G; Lupton, R; McDonald, P; Medolin, B; Muna, D; Miralda-Escudé, J; Myers, A D; Nichol, R C; Palanque-Delabrouille, N; Pâris, I; Petitjean, P; Piškur, Y; Rollinde, E; Ross, N P; Schlegel, D J; Schneider, D P; Sheldon, E; Weaver, B A; Weinberg, D H; Yeche, C; York, D G (2011). *The Lyman-α forest in three dimensions: measurements of large scale flux correlations from BOSS 1st-year data.* Journal of Cosmology and Astroparticle Physics, (09):001.

## Abstract

Using a sample of approximately 14,000 z>2.1 quasars observed in the first year of the Baryon Oscillation Spectroscopic Survey (BOSS), we measure the three-dimensional correlation function of absorption in the Lyman-alpha forest. The angle-averaged correlation function of transmitted flux (F = exp(-tau)) is securely detected out to comoving separations of 60 Mpc/h, the first detection of flux correlations across widely separated sightlines. A quadrupole distortion of the redshift-space correlation function by peculiar velocities, the signature of the gravitational instability origin of structure in the Lyman-alpha forest, is also detected at high significance. We obtain a good fit to the data assuming linear theory redshift-space distortion and linear bias of the transmitted flux, relative to the matter fluctuations of a standard LCDM cosmological model (inflationary cold dark matter with a cosmological constant). At 95% confidence, we find a linear bias parameter 0.16<b<0.24 and redshift-distortion parameter 0.44<beta<1.20, at central redshift z=2.25, with a well constrained combination b(1+\beta)=0.336 +/- 0.012. The errors on beta are asymmetric, with beta=0 excluded at over 5 sigma confidence level. The value of beta is somewhat low compared to theoretical predictions, and our tests on synthetic data suggest that it is depressed (relative to expectations for the Lyman-alpha forest alone) by the presence of high column density systems and metal line absorption. These results set the stage for cosmological parameter determinations from three-dimensional structure in the Lyman-alpha forest, including anticipated constraints on dark energy from baryon acoustic oscillations.

## Citations

## Altmetrics

## Downloads

## Additional indexing

Item Type: | Journal Article, refereed, original work |
---|---|

Communities & Collections: | 07 Faculty of Science > Institute for Computational Science |

Dewey Decimal Classification: | 530 Physics |

Language: | English |

Date: | 2011 |

Deposited On: | 23 Feb 2012 22:18 |

Last Modified: | 05 Apr 2016 15:41 |

Publisher: | Institute of Physics Publishing |

ISSN: | 1475-7516 |

Additional Information: | This is an author-created, un-copyedited version of an article accepted for publication in Journal of Cosmology and Astroparticle Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at 10.1088/1475-7516/2011/09/001 |

Publisher DOI: | 10.1088/1475-7516/2011/09/001 |

Related URLs: | http://arxiv.org/abs/1011.3458 |

## Download

Language: English

Filetype: PDF - Registered users only

Size: 5MB

View at publisher

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.

You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.