New insights on low-mass dark matter subhalo tidal tracks via numerical simulations

Abstract

Many studies assert that dark matter (DM) subhaloes without a baryonic counterpart and with an inner cusp always survive no matter the strength of the tidal force they undergo. In this work, we perform a suite of numerical simulations specifically designed to analyse the evolution of $V_{\max }$, $r_{\max }$ and concentration of low-mass DM subhaloes due to tidal stripping. We employ the improved version of the DASH code, introduced in our previous work arXiv:2207.08652 to investigate subhalo survival. We follow the tidal evolution of a single DM subhalo orbiting a Milky Way (MW)-size halo modeled with a baryonic disc and a bulge replicating the actual mass distribution of the MW. We consider the effect of the time-evolving gravitational potential of the MW itself. We simulate subhaloes with unprecedented accuracy, varying their initial concentration, orbital parameters, and inner slope (both NFW and prompt cusps are considered). Unlike the previous literature, we examine the evolution of subhalo structural parameters -- tidal tracks -- not only at orbit apocentres but also at pericentres, finding in the former case both similarities and differences -- particularly pronounced in the case of prompt cusps. Overall, $r_{\max }$ shrinks more than $V_{\max }$, leading to a continuous rise of subhalo concentration with time. The velocity concentration at present is found to be around two orders of magnitude higher than the one at infall, being comparatively larger for pericentre tidal tracks versus apocentres. These findings highlight the dominant role of tidal effects in reshaping low-mass DM subhaloes, providing valuable insights for future research via simulations and observations, such as correctly interpreting data from galaxy satellite populations, subhalo searches with gravitational lensing or stellar stream analyses, and indirect DM searches.

17 pages, 19 figures, 4 tables. Matches MNRAS published version

References in corpus (29)

• The NumPy array: a structure for efficient numerical computation
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
• The Tidal Evolution of Local Group Dwarf Spheroidals
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
• Bent by baryons: the low mass galaxy-halo relation
• Large-scale dark matter simulations
• The moment of truth for WIMP Dark Matter
• Hierarchical Formation of Dark Matter Halos and the Free Streaming Scale
• The asymptotic tidal remnants of cold dark matter subhalos
• Determining the full satellite population of a Milky Way-mass halo in a highly resolved cosmological hydrodynamic simulation
• The tidal evolution of dark matter substructure -- I. Subhalo density profiles
• Inner cusps of the first dark matter haloes: Formation and survival in a cosmological context
• DASH: a library of dynamical subhalo evolution
• What sets the central structure of dark matter haloes?
• LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations
• Tidal Stripping in the Adiabatic Limit
• Tidal Tracks and Artificial Disruption of Cold Dark Matter Halos
• Dynamical self-friction: how mass loss slows you down
• Prompt cusps and the dark matter annihilation signal
• Baryonic effects on the detectability of annihilation radiation from dark matter subhaloes around the Milky Way
• Tidal evolution of cored and cuspy dark matter halos
• The AGORA High-resolution Galaxy Simulations Comparison Project. V: Satellite Galaxy Populations In A Cosmological Zoom-in Simulation of A Milky Way-mass Halo
• Shedding light on low-mass subhalo survival and annihilation luminosity with numerical simulations
• The Impact of Molecular Hydrogen Cooling on the Galaxy Formation Threshold
• The cusp-halo relation
• Why artificial disruption is not a concern for current cosmological simulations

Cited by in corpus (2)

• Impact of baryons on the population of Galactic subhalos and implications for dark matter searches
• Imprints of tidal interactions on the stellar distribution of satellite galaxies: implications for dark matter deficient galaxies