The large-scale Quasar-Lyman α Forest Cross-Correlation from BOSS

Дата и время публикации : 2013-03-08T10:24:48Z

Авторы публикации и институты :
Andreu Font-Ribera
Eduard Arnau
Jordi Miralda-Escudé
Emmanuel Rollinde
J. Brinkmann
Joel R. Brownstein
Khee-Gan Lee
Adam D. Myers
Nathalie Palanque-Delabrouille
Isabelle Pâris
Patrick Petitjean
James Rich
Nicholas P. Ross
Donald P. Schneider
Martin White

Ссылка на журнал-издание: JCAP05(2013)018
Коментарии к cтатье: 24 pages, 6 figures, published in JCAP
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO

Краткий обзор статьи: We measure the large-scale cross-correlation of quasars with the Lyman alpha forest absorption in redshift space, using ~ 60000 quasar spectra from Data Release 9 (DR9) of the Baryon Oscillation Spectroscopic Survey (BOSS). The cross-correlation is detected over a wide range of scales, up to comoving separations r of 80 Mpc/h. For r > 15 Mpc/h, we show that the cross-correlation is well fitted by the linear theory prediction for the mean overdensity around a quasar host halo in the standard Lambda CDM model, with the redshift distortions indicative of gravitational evolution detected at high confidence. Using previous determinations of the Lyman alpha forest bias factor obtained from the Lyman alpha autocorrelation, we infer the quasar bias factor to be b_q = 3.64^+0.13_-0.15 at a mean redshift z=2.38, in agreement with previous measurements from the quasar auto-correlation. We also obtain a new estimate of the Lyman alpha forest redshift distortion factor, beta_F = 1.1 +/- 0.15, slightly larger than but consistent with the previous measurement from the Lyman alpha forest autocorrelation. The simple linear model we use fails at separations r < 15 Mpc/h, and we show that this may reasonably be due to the enhanced ionization due to radiation from the quasars. We also provide the expected correction that the mass overdensity around the quasar implies for measurements of the ionizing radiation background from the line-of-sight proximity effect.

Category: Physics