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arXiv · 2610.03544

Baryonic Imprints on DM Halos: the concentration-mass relation and its dependence on 28 model parameters in the CAMELS suite

Cami Delgado·Dhayaa Anbajagane
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Abstract

The evolution of baryons in halos, as well as their gravitational impact on the total-matter phase space, has a rich phenomenology and is vital in answering many questions in both cosmology and astrophysics. We use the CAMELS simulation suite to quantify the impact of twenty-three different galaxy formation parameters/processes (as well as five cosmological parameters) on the concentration--mass relation, $c_{\rm vir}$ - $M_{\rm vir}$, which characterizes the radial density distribution in halos. We construct a simulation-informed nonlinear model for concentration as a function of halo mass, redshift, and twenty-eight cosmological/astrophysical parameters. This is done using 2048 simulations of the IllustrisTNG galaxy formation model from the CAMELS suite. We extract the imprints of galaxy formation across a wide range in mass $M_{\rm vir} \in [10^{11}, 10^{14.5}]$ $M_{\odot}/h$ and in redshift $z \in [0, 3]$, finding clear mass- and redshift-dependent features in each of the different feedback mechanisms. From our measurements, we construct a three-component phenomenological model that can include astrophysical imprints in the concentration--mass relation in a fast and simple manner.

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Cami Delgado, Dhayaa Anbajagane. 2026-10-02. Baryonic Imprints on DM Halos: the concentration-mass relation and its dependence on 28 model parameters in the CAMELS suite. https://arxiv.org/abs/2610.03544

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