LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations

Moliné, Ángeles; Aguirre-Santaella, Alejandra; Ishiyama, Tomoaki; Prada, Francisco; Cora, S. A.; Croton, Darren J.; Jullo, Eric; Metcalf, R. Benton; Oogi, Taira; Ruedas, José

doi:10.48550/arxiv.2110.02097

Cited by 3 publications

(3 citation statements)

References 60 publications

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“…Less concentrated halos are less resilient to tidal disruption. A similar trend has been observed when considering the distance to the host in that the closer subhalos have higher concentrations on average than more distant subhalos (Moliné et al 2021). This observed trend between pericenter and dark matter density has been used to probe self-interacting dark matter (e.g., Jiang et al 2021).…”

Section: K19 Correlationsupporting

confidence: 68%

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Pace¹,

Erkal²,

Li³

2022

Preprint

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We measure systemic proper motion of 52 dwarf spheroidal (dSph) satellite galaxies of the Milky Way (MW). We combine Gaia EDR3 astrometry with accurate photometry and utilize a probabilistic mixture model to determine the systemic proper motions and identify likely dSph members. For the 46 dSphs with literature line-of-sight velocities we compute orbits in both a MW and a combined MW + Large Magellanic Cloud (LMC) potential and identify likely LMC satellites. For these orbits, we Monte Carlo sample over the observational uncertainties for each dSph as well as the uncertainties in the MW and LMC potentials. We explore orbital parameters and previously used diagnostics for probing the MW tidal influence on the dSph population. We find that signatures of tidal influence by the MW are easily seen by comparing a dSph's pericenter and its average density relative to the MW at its pericenter. dSphs with large ellipticity show a preference for their orbital direction to align with their major axis even if they do not have a small pericenter. We compare the radial orbital phase of our dSph sample to subhalos in MW-like N -body simulations and find that the distributions are similar and that there is not an excess of satellites near their pericenter. With future Gaia data releases, we find that the orbital precision of most dSphs will be limited by uncertainties in distance and/or the MW potential rather than proper motion precision. Finally, we provide our membership lists to enable community follow-up.

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Section: K19 Correlationsupporting

confidence: 68%

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Pace¹,

Erkal²,

Li³

2022

Preprint

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show abstract

“…Less concentrated halos are less resilient to tidal disruption. A similar trend has been observed when considering the distance to the host in that the closer subhalos have higher concentrations on average than more distant subhalos (Moliné et al 2021). This observed trend between the pericenter and dark matter density has been used to probe self-interacting dark matter (e.g., Jiang et al 2021).…”

Section: On the Anticorrelation Between The Pericenter And Density Fo...supporting

confidence: 68%

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Pace

Erkal

2022

ApJ

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We combine Gaia early data release 3 astrometry with accurate photometry and utilize a probabilistic mixture model to measure the systemic proper motion of 52 dwarf spheroidal (dSph) satellite galaxies of the Milky Way (MW). For the 46 dSphs with literature line-of-sight velocities we compute orbits in both a MW and a combined MW + Large Magellanic Cloud (LMC) potential and identify Car II, Car III, Hor I, Hyi I, Phx II, and Ret II as likely LMC satellites. 40% of our dSph sample has a >25% change in pericenter and/or apocenter with the MW + LMC potential. For these orbits, we use a Monte Carlo sample for the observational uncertainties for each dSph and the uncertainties in the MW and LMC potentials. We predict that Ant II, Boo III, Cra II, Gru II, and Tuc III should be tidally disrupting by comparing each dSph's average density relative to the MW density at its pericenter. dSphs with large ellipticity (CVn I, Her, Tuc V, UMa I, UMa II, UMi, Wil 1) show a preference for their orbital direction to align with their major axis even for dSphs with large pericenters. We compare the dSph radial orbital phase to subhalos in MW-like N-body simulations and infer that there is not an excess of satellites near their pericenter. With projections of future Gaia data releases, we find that dSph's orbital precision will be limited by uncertainties in the distance and/or MW potential rather than in proper motion precision. Finally, we provide our membership catalogs to enable community follow-up.

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“…Those data are available on Skies & Universes site. Further details of the Shin-Uchuu simulation and its basic halo and subhalo properties are presented in the literature (Ishiyama et al 2021 ;Moline et al 2021 ).…”

Section: N U M E R I C a L S I M U L At I O Nmentioning

confidence: 99%

Semi-analytical frameworks for subhaloes from the smallest to the largest scale

Hiroshima¹,

Ando²,

Ishiyama³

2022

Monthly Notices of the Royal Astronomical Society

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Substructures of dark matter halo, called subhalos, provide important clues to understand the nature of dark matter. We construct a useful model to describe the properties of subhalo mass functions based on the well-known analytical prescriptions, the extended Press-Schechter theory. The unevolved subhalo mass functions at arbitrary mass scales become describable without introducing free parameters. The different host halo evolution histories are directly recast to their subhalo mass functions. As applications, we quantify the effects from (i) the Poisson fluctuation, (ii) the host mass scatter, and the (iii) different tidal evolution models on observables in the current Universe with this scheme. The Poisson fluctuation dominates in the number count of the mass ratio to the host of $\sim {\cal O}(10^{-2})$, where the intrinsic scatter is smaller by a factor of a few. The host-mass scatter around its mean does not affect the subhalo mass function. Different models of the tidal evolution predict a factor of ∼2 difference in numbers of subhalos with $\lesssim {\cal O}(10^{-5})$, while the dependence of the Poisson fluctuation on the tidal evolution models is subtle. The scheme provides a new tool for investigating the smallest-scale structures of our Universe which are to be observed in near future experiments.

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LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations

Cited by 3 publications

References 60 publications

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies

Semi-analytical frameworks for subhaloes from the smallest to the largest scale

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