The impact of galactic feedback on the shapes of dark-matter haloes

Abstract

We quantify the impact of galaxy formation on dark matter halo shapes using cosmological simulations at redshift $z=0$. The haloes are drawn from the IllustrisTNG project, a suite of magneto-hydrodynamic simulations of galaxies. We focus on haloes of mass $10^{10-14}{M}_{\odot }$ from the 50-Mpc (TNG50) and 100-Mpc (TNG100) boxes, and compare them to dark matter-only (DMO) analogues and other simulations e.g. NIHAO and Eagle. We further quantify the prediction uncertainty by varying the baryonic feedback models in a series of smaller 25 Mpc $h^{-1}$ boxes. We find that: (i) galaxy formation results in rounder haloes compared to the DMO simulations, in qualitative agreement with past hydrodynamic models. Haloes of mass $\approx 2\times 10^{12}{M}_{\odot }$ are most spherical, with an average minor-to-major axis ratio of $⟨s⟩\approx 0.75$ in the inner halo, an increase of 40 per cent compared to their DMO counterparts. No significant change in halo shape is found for low-mass $10^{10}{M}_{\odot }$ haloes; (ii) stronger feedback, e.g. increasing galactic wind speed, reduces the impact of baryons; (iii) the inner halo shape correlates with the stellar mass fraction, which can explain the dependence of halo shapes on different feedback models; (iv) the fiducial and weaker feedback models are most consistent with observational estimates of the Milky Way halo shape. Yet, at fixed halo mass, very diverse and possibly unrealistic feedback models all predict inner halo shapes that are closer to one another than to the DMO results. This implies that a larger observational sample would be required to statistically distinguish between different baryonic prescriptions due to large halo-to-halo variation in halo shapes.

18 pages, 12 figures

References in corpus (16)

• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• Properties of galaxies reproduced by a hydrodynamic simulation
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The Causes of Halo Shape Changes Induced by Cooling Baryons: Disks Versus Substructures
• The shape of the inner Milky Way halo from observations of the Pal 5 and GD-1 stellar streams
• The Shape of the Gravitational Potential in Cold Dark Matter Halos
• The Impact of Galactic Feedback on the Circumgalactic Medium
• Dark matter halo shapes in the Auriga simulations
• High redshift JWST predictions from IllustrisTNG: II. Galaxy line and continuum spectral indices and dust attenuation curves
• High redshift JWST predictions from IllustrisTNG: III. Infrared luminosity functions, obscured star formation and dust temperature of high-redshift galaxies
• DM halo morphological types of MW-like galaxies in the TNG50 simulation: Simple, Twisted, or Stretched
• Baryons Shaping Dark Matter Haloes
• A Lower Limit on the Mass of Our Galaxy from the H3 Survey

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