KiDS-1000: Constraints on the intrinsic alignment of luminous red galaxies

Abstract

We constrain the luminosity and redshift dependence of the intrinsic alignment (IA) of a nearly volume-limited sample of luminous red galaxies selected from the fourth public data release of the Kilo-Degree Survey (KiDS-1000). To measure the shapes of the galaxies, we used two complementary algorithms, finding consistent IA measurements for the overlapping galaxy sample. The global significance of IA detection across our two independent luminous red galaxy samples, with our favoured method of shape estimation, is ∼ 10.7σ. We find no significant dependence with redshift of the IA signal in the range 0.2 < z < 0.8, nor a dependence with luminosity below L r 2.9 × 10 10 h −2 L r, . Above this luminosity, however, we find that the IA signal increases as a power law, although our results are also compatible with linear growth within the current uncertainties. This behaviour motivates the use of a broken power law model when accounting for the luminosity dependence of IA contamination in cosmic shear studies.

The Quasar Candidate Catalogs of DESI Legacy Imaging Survey Data Release 9

“…SDSS eBOSS DR16-The Sloan Digital Sky Survey (SDSS, see, e.g., York et al 2000, for more details) is a major multispectral imaging and spectroscopic redshift survey and has a long-running history of more than 20 yr. The eBOSS (grounded upon SDSS-IV, Blanton et al 2017) is an extended project of BOSS (Baryon Oscillation Spectroscopic Survey, grounded upon SDSS-III, Eisenstein et al 2011;Dawson et al 2013), which maps the LRGs (luminous red galaxies, Zhou et al 2020;Fortuna et al 2021) and quasars to determine the characteristic scale of BAOs imprinted at the large-scale structure. eBOSS covers a broader range of redshifts than that of BOSS.…”