Beyond Mass: Detecting Secondary Halo Properties with Galaxy-Galaxy Lensing

Abstract

Secondary halo properties beyond mass, such as the mass accretion rate (MAR), concentration, and the half mass scale, are essential in understanding the formation of large-scale structure and dark matter halos. In this paper, we study the impact of secondary halo properties on the galaxy-galaxy lensing observable, ΔΣ. We build an emulator trained on N-body simulations to model ΔΣ and quantify the impact of different secondary parameters on the ΔΣ profile. We focus on the impact of MAR on ΔΣ. We show that a 3𝜎 detection of variations in MAR at fixed halo mass could be achieved with the Hyper Suprime Cam survey in combination with a proxy for MAR with scatter 𝜎 Γ dyn |obs < 1.5. We show that the full radial profile of ΔΣ depends on secondary properties at fixed halo mass. Consequently, an emulator that can perform full shape fitting yields better than 2 times improvement upon the constraints on MAR than only using the outer part of the halo. Finally, we highlight that miscentering and MAR impact the radial profile of ΔΣ in a similar fashion, implying that miscentering and MAR need to be modeled jointly for unbiased estimates of both effects. We show that present-day lensing data sets have the statistical capability to place constraints on halo MAR. Our analysis opens up new possibilities for observationally measuring the assembly history of the dark matter halos that host galaxies and clusters.

A dynamics-based density profile for dark haloes. I. Algorithm and basic results

“…The halo outskirts (r > ∼ 0.5 R vir ) have recently received renewed attention because they turn out to be sensitive to otherwise inaccessible halo properties such as the mass accretion rate (Diemer & Kravtsov 2014, hereafter DK14; see also Xhakaj et al 2020Xhakaj et al , 2021, the nature of dark matter (Banerjee et al 2020), and deviations from General Relativity (Adhikari et al 2018;Contigiani et al 2019a). At the same time, rapid observational progress has led to high-accuracy constraints on profiles from profiles of satellites in individual clusters (Rines et al 2013;Tully 2015;Patej & Loeb 2016), in stacked clusters (More et al 2016;Baxter et al 2017;Nishizawa et al 2018;Zürcher & More 2019;Murata et al 2020), and in weak lensing profiles (Mandelbaum et al 2006;Umetsu et al 2011;Umetsu & Diemer 2017;Contigiani et al 2019b;Chang et al 2018;Shin et al 2019Shin et al , 2021.…”

Properties beyond mass for unresolved haloes across redshift and cosmology using correlations with local halo environment

“…Many analytic models predict connections between halo angular momentum and galactic disc rotation (Fall & Efstathiou 1980;Mo et al 1998) and more recent attempts try to measure the spin of the halo from the baryonic components (Obreja et al 2021). Possibilities of constraining other halo properties using observations are also explored (Brimioulle et al 2013), sometimes demonstrated using halo catalogs (Behroozi et al 2021;Xhakaj et al 2021).…”