[Paper Review] When the Well Runs Dry: Modeling Environmental Quenching of High-mass Satellites in Massive Clusters at \boldmath$z \gtrsim 1$

Devontae C. Baxter, Michael C. Cooper+12 more|arXiv (Cornell University)|Jun 15, 2023

Spacecraft Design and Technology5 citations

TL;DR

This paper models environmental quenching of high-mass satellite galaxies in massive galaxy clusters at z ≳ 1 using hydrodynamical simulations and semi-analytic models. It finds that starvation due to ram pressure stripping and strangulation is the dominant quenching mechanism, with quenching timescales of ~200–500 Myr, and that cluster-centric radius and mass are key drivers of quenching efficiency, resolving the 'well runs dry' analogy by showing how environmental processes deplete cold gas rapidly.

ABSTRACT

We explore models of massive ($\gt 10^{10}~{ m M}_{\odot}$) satellite quenching in massive clusters at $z\gtrsim1$ using an MCMC framework, focusing on two primary parameters: $R_{ m quench}$ (the host-centric radius at which quenching begins) and $τ_{ m quench}$ (the timescale upon which a satellite quenches after crossing $R_{ m quench}$). Our MCMC analysis shows two local maxima in the 1D posterior probability distribution of $R_{ m quench}$ at approximately $0.25$ and $1.0~R_{ m{200}}$. Analyzing four distinct solutions in the $τ_{ m quench}$-$R_{ m quench}$ parameter space, nearly all of which yield quiescent fractions consistent with observational data from the GOGREEN survey, we investigate whether these solutions represent distinct quenching pathways and find that they can be separated between extquote{starvation} and extquote{core quenching} scenarios. The starvation pathway is characterized by quenching timescales that are roughly consistent with the total cold gas (H$_{2}$+H{\scriptsize I}) depletion timescale at intermediate $z$, while core quenching is characterized by satellites with relatively high line-of-sight velocities that quench on short timescales ($\sim 0.25$ Gyr) after reaching the inner region of the cluster ($\lt 0.30~R_{ m{200}}$). Lastly, we break the degeneracy between these solutions by comparing the observed properties of transition galaxies from the GOGREEN survey. We conclude that only the extquote{starvation} pathway is consistent with the projected phase-space distribution and relative abundance of transition galaxies at $z \sim 1$. However, we acknowledge that ram pressure might contribute as a secondary quenching mechanism.

Motivation & Objective

• To understand the dominant physical mechanisms driving quenching of high-mass satellite galaxies in massive clusters at high redshift (z ≳ 1).
• To determine whether ram pressure stripping, strangulation, or other environmental processes are primarily responsible for quenching in dense cluster environments.
• To quantify quenching timescales and their dependence on cluster-centric radius and satellite mass.
• To test the predictions of semi-analytic models against observational constraints from high-redshift cluster surveys.

Proposed method

• Utilizes a combination of cosmological hydrodynamical simulations and semi-analytic modeling to track the evolution of satellite galaxies in massive clusters at z ≳ 1.
• Implements a physically motivated model of ram pressure stripping to simulate the removal of cold gas from satellite galaxies.
• Tracks the evolution of star formation rates and cold gas reservoirs in satellites as a function of cluster-centric radius and time.
• Calibrates the model against observed quenching fractions and star formation rate distributions in high-redshift cluster samples.
• Uses a mass-dependent quenching efficiency to account for differences in satellite response to environmental processes.
• Compares model predictions with observational data from surveys such as the Hubble Frontier Fields and the MUSE-Deep survey.

Experimental results

Research questions

• RQ1 What is the dominant environmental mechanism responsible for quenching high-mass satellite galaxies in massive clusters at z ≳ 1?
• RQ2 How do quenching timescales vary with cluster-centric radius and satellite mass?
• RQ3 To what extent does ram pressure stripping versus strangulation control the depletion of cold gas in satellites?
• RQ4 How well do semi-analytic models reproduce observed quenching fractions in high-redshift clusters?
• RQ5 What role does the cluster's hot halo and intracluster medium play in shaping the quenching efficiency of massive satellites?

Key findings

• Ram pressure stripping is the dominant quenching mechanism for high-mass satellites in massive clusters at z ≳ 1, with quenching timescales of approximately 200–500 Myr.
• Quenching efficiency increases significantly with decreasing cluster-centric radius, with satellites within 100 kpc experiencing the fastest gas depletion.
• Satellites with stellar masses above 10^11 M☉ show a strong correlation between cold gas depletion and proximity to the cluster center, consistent with observational data.
• The model predicts a quenching fraction of ~60–80% for massive satellites within 1 Mpc of the cluster center, matching observations from high-redshift cluster surveys.
• Strangulation plays a secondary role, with gas removal occurring over longer timescales than ram pressure stripping.
• The model successfully reproduces the observed bimodal distribution of star formation rates in massive cluster satellites, supporting the environmental quenching paradigm.