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author Garcia, Alex M.
Rose, Jonah C.
Torrey, Paul
Caputo, Andrea
Lisanti, Mariangela
Pace, Andrew B.
Liu, Hongwan
Hussein, Abdelaziz
Liu, Haozhe
Villaescusa-Navarro, Francisco
Barry, John
Leisher, Ilem
Costanza, Belén
Kho, Jonathan
Lilie, Ethan
Li, Jiaxuan
Ahvazi, Niusha
Bhowmick, Aklant
Nguyen, Tri
O'Neil, Stephanie
Ou, Xiaowei
Shen, Xuejian
Farahi, Arya
Kallivayalil, Nitya
Necib, Lina
Vogelsberger, Mark
author_facet Garcia, Alex M.
Rose, Jonah C.
Torrey, Paul
Caputo, Andrea
Lisanti, Mariangela
Pace, Andrew B.
Liu, Hongwan
Hussein, Abdelaziz
Liu, Haozhe
Villaescusa-Navarro, Francisco
Barry, John
Leisher, Ilem
Costanza, Belén
Kho, Jonathan
Lilie, Ethan
Li, Jiaxuan
Ahvazi, Niusha
Bhowmick, Aklant
Nguyen, Tri
O'Neil, Stephanie
Ou, Xiaowei
Shen, Xuejian
Farahi, Arya
Kallivayalil, Nitya
Necib, Lina
Vogelsberger, Mark
contents In this work, we utilize a new suite of Milky Way-mass halos from the DREAMS Project, simulated with Cold Dark Matter (CDM), to quantify the influence of baryon feedback and intrinsic halo-to-halo variance on dark matter density profiles. Our suite of 1024 halos varies over supernova and black hole feedback parameters from the IllustrisTNG model, as well as variations in two cosmological parameters. We find that, for the DREAMS parameter variations, Milky Way-mass dark matter density profiles in the IllustrisTNG model are largely insensitive to astrophysics and cosmology variations, with the dominant source of scatter instead arising from halo-to-halo variance. However, most of the (comparatively minor) feedback-driven variations come from the changes to supernova prescriptions. By comparing to dark matter-only simulations, we find that the strongest supernova wind energies are so effective at preventing galaxy formation that the halos are nearly entirely collisionless dark matter. Finally, regardless of physics variation, all the DREAMS halos are roughly consistent with a halo contracting adiabatically from the presence of baryons, unlike models that have bursty stellar feedback. This work represents a step toward assessing the uncertainty in Milky Way dark matter profiles, with direct implications for dark matter searches where systematic uncertainty in the density profile remains a major challenge.
format Preprint
id arxiv_https___arxiv_org_abs_2512_03132
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The DREAMS Project: Disentangling the Impact of Halo-to-Halo Variance and Baryonic Feedback on Milky Way Dark Matter Density Profiles
Garcia, Alex M.
Rose, Jonah C.
Torrey, Paul
Caputo, Andrea
Lisanti, Mariangela
Pace, Andrew B.
Liu, Hongwan
Hussein, Abdelaziz
Liu, Haozhe
Villaescusa-Navarro, Francisco
Barry, John
Leisher, Ilem
Costanza, Belén
Kho, Jonathan
Lilie, Ethan
Li, Jiaxuan
Ahvazi, Niusha
Bhowmick, Aklant
Nguyen, Tri
O'Neil, Stephanie
Ou, Xiaowei
Shen, Xuejian
Farahi, Arya
Kallivayalil, Nitya
Necib, Lina
Vogelsberger, Mark
Astrophysics of Galaxies
In this work, we utilize a new suite of Milky Way-mass halos from the DREAMS Project, simulated with Cold Dark Matter (CDM), to quantify the influence of baryon feedback and intrinsic halo-to-halo variance on dark matter density profiles. Our suite of 1024 halos varies over supernova and black hole feedback parameters from the IllustrisTNG model, as well as variations in two cosmological parameters. We find that, for the DREAMS parameter variations, Milky Way-mass dark matter density profiles in the IllustrisTNG model are largely insensitive to astrophysics and cosmology variations, with the dominant source of scatter instead arising from halo-to-halo variance. However, most of the (comparatively minor) feedback-driven variations come from the changes to supernova prescriptions. By comparing to dark matter-only simulations, we find that the strongest supernova wind energies are so effective at preventing galaxy formation that the halos are nearly entirely collisionless dark matter. Finally, regardless of physics variation, all the DREAMS halos are roughly consistent with a halo contracting adiabatically from the presence of baryons, unlike models that have bursty stellar feedback. This work represents a step toward assessing the uncertainty in Milky Way dark matter profiles, with direct implications for dark matter searches where systematic uncertainty in the density profile remains a major challenge.
title The DREAMS Project: Disentangling the Impact of Halo-to-Halo Variance and Baryonic Feedback on Milky Way Dark Matter Density Profiles
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2512.03132