文章基本信息

标题：The stellar-to-halo mass relation over the past 12 Gyr
其他标题：I. Standard ΛCDM model
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作者：G. Girelli ; L. Pozzetti ; M. Bolzonella 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2020
卷号：634
页码：1-23
DOI：10.1051/0004-6361/201936329
语种：English
出版社：EDP Sciences
摘要：Aims.Understanding the link between the galaxy properties and the dark matter halos they reside in and their coevolution is a powerful tool for constraining the processes related to galaxy formation. In particular, the stellar-to-halo mass relation (SHMR) and its evolution throughout the history of the Universe provides insights on galaxy formation models and allows us to assign galaxy masses to halos inN-body dark matter simulations. To address these questions, we determine the SHMR throughout the entire cosmic history fromz ∼ 4 to the present.Methods.We used a statistical approach to link the observed galaxy stellar mass functions on the COSMOS field to dark matter halo mass functions up toz ∼ 4 from the ΛCDMDUSTGRAIN-pathfindersimulation, which is complete forMh > 1012.5 M⊙, and extended this to lower masses with a theoretical parameterization. We propose an empirical model to describe the evolution of the SHMR as a function of redshift (either in the presence or absence of a scatter in stellar mass at fixed halo mass), and compare the results with several literature works and semianalytic models of galaxy formation. We also tested the reliability of our results by comparing them to observed galaxy stellar mass functions and to clustering measurements.Results.We derive the SHMR fromz = 0 toz = 4, and model its empirical evolution with redshift. We find thatM*/Mhis always lower than ∼0.05 and depends both on redshift and halo mass, with a bell shape that peaks atMh ∼ 1012 M⊙. Assuming a constant cosmic baryon fraction, we calculate the star-formation efficiency of galaxies and find that it is generally low; its peak increases with cosmic time from ∼30% atz ∼ 4 to ∼35% atz ∼ 0. Moreover, the star formation efficiency increases for increasing redshifts at masses higher than the peak of the SHMR, while the trend is reversed for masses lower than the peak. This indicates that massive galaxies (i.e., galaxies hosted at halo masses higher than the SHMR peak) formed with a higher efficiency at higher redshifts (i.e., downsizing effect) and vice versa for low-mass halos. We find a large scatter in results from semianalytic models, with a difference of up to a factor ∼8 compared to our results, and an opposite evolutionary trend at high halo masses. By comparing our results with those in the literature, we find that while atz ∼ 0 all results agree well (within a factor of ∼3), atz > 0 many differences emerge. This suggests that observational and theoretical work still needs to be done. Our results agree well (within ∼10%) with observed stellar mass functions (out toz = 4) and observed clustering of massive galaxies (M* > 1011 M⊙fromz ∼ 0.5 toz ∼ 1.1) in the two-halo regime.
关键词：engalaxies: formationgalaxies: evolutioncosmology: observationsgalaxies: luminosity function, mass functiondark mattergalaxies: high-redshift