THE CONCENTRATION DEPENDENCE OF THE GALAXY-HALO CONNECTION: MODELING ASSEMBLY BIAS WITH ABUNDANCE MATCHING

• Published in: The Astrophysical journal Vol. 834; no. 1; pp. 37 - 49
• Main Authors: Lehmann, Benjamin V., Mao, Yao-Yuan, Becker, Matthew R., Skillman, Samuel W., Wechsler, Risa H.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01-01-2017; IOP Publishing; Institute of Physics (IOP)
• Subjects: Abundance; Assembly; ASTRO; Astronomical catalogs; Astronomical models; ASTRONOMY AND ASTROPHYSICS; Astrophysics; Bias; Clustering; Computer simulation; Dark matter; Dependence; Galactic halos; Galaxies; galaxies: halos; Halos; Interpolation; Luminosity; methods: analytical; methods: numerical; Model matching; Parameterization; Red shift; Stars & galaxies
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/834/1/37

ABSTRACT Empirical methods for connecting galaxies to their dark matter halos have become essential for interpreting measurements of the spatial statistics of galaxies. In this work, we present a novel approach for parameterizing the degree of concentration dependence in the abundance matching method. This new parameterization provides a smooth interpolation between two commonly used matching proxies: the peak halo mass and the peak halo maximal circular velocity. This parameterization controls the amount of dependence of galaxy luminosity on halo concentration at a fixed halo mass. Effectively this interpolation scheme enables abundance matching models to have adjustable assembly bias in the resulting galaxy catalogs. With the new DarkSky Simulation, whose larger volume provides lower sample variance, we further show that low-redshift two-point clustering and satellite fraction measurements from SDSS can already provide a joint constraint on this concentration dependence and the scatter within the abundance matching framework.