2018/09/30 by Jiashu Han, Simone Ferraro, Elena Giusarma +1
Physics and Astronomy · #Anisotropy #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Cosmic microwave background #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitational lens #Halo #Optics #Physics #Quasar #Redshift #Sky #Weak gravitational lensing #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stz528
published as MNRAS 485 (2019) 1720-1726 · 8 pages, 6 figures, 1 table; matches published version on MNRAS
openalex publication_date 2019/02/20 · arxiv created 2019/02/21 · arxiv updated 2019/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We study the cross-correlation between the Planck cosmic microwave background (CMB) lensing convergence map and the extended-Baryon Oscillation Spectroscopic Survey (e-BOSS) quasar overdensity obtained from the Sloan Digital Sky Survey (SDSS) IV, in the redshift range 0.9 < |z| < 2.2. We detect the CMB lensing convergence–quasar cross-power spectrum at 5.4σ significance. The cross-power spectrum provides a quasar clustering bias measurement that is expected to be particularly robust against systematic effects. The redshift distribution of the quasar sample has a median redshift |z| ≈ 1.55, and an effective redshift about 1.51. The best-fitting bias of the quasar sample is bq = 2.43 ± 0.45, corresponding to a host halo mass of |log 10(\fracMh-1 M_\odot ) = 12.54+0.25-0.36|. This is broadly consistent with the previous literature on quasars with a similar redshift range and selection. Since our constraint on the bias comes from the cross-correlation between quasars and CMB lensing, we expect it to be robust to a wide range of possible systematic effects that may contaminate the autocorrelation of quasars. We checked for a number of systematic effects from both CMB lensing and quasar overdensity, and found that all systematics are consistent with null within 2σ. The data are not sensitive to a possible scale dependence of the bias at present, but we expect that as the number of quasars increases [in future surveys such as Dark Energy Spectroscopic Instrument (DESI)], it is likely that strong constraints on the scale dependence of the bias can be obtained.