Orbital parameters of infalling dark matter substructures

By A. Benson. 2004

183 citations recorded by the source corpus.

We present distributions of the orbital parameters of dark matter substructures at the time of merging into their host halo. Accurate knowledge of the orbits of dark matter substructures is a crucial input to studies which aim to assess the effects of the cluster environment on galaxies, the heating of galaxy discs and many other topics. Orbits are measured for satellites in a large number of N-body simulations. We focus on the distribution of radial and tangential velocities, but consider also distributions of orbital eccentricity and semimajor axis. We show that the distribution of radial and tangential velocities has a simple form and provide a fitting formula for this distribution. We also search for possible correlations between the infall directions of pairs of satellites, finding evidence for positive correlation at small angular separations as expected if some infall occurs along filaments. We also find (weak) evidence for correlations between the direction of the infall and infall velocity and the spin of the host halo.

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Citations in the corpus

THE MAJOR AND MINOR GALAXY MERGER RATES AT z < 1.5 (2011, background): “Large-scale numerical simulations find that the majority of dark-matter halo mergers are parabolic as opposed to circular (Khochfar & Burkert 2006; Benson 2005; Wetzel 2010), with only modest evolution in the typical orbital eccentricity out to z ∼ 1.5 (Wetzel 2010).”
Tracing Galaxy Formation with Stellar Halos. I. Methods (2005, result): “…ǫ from the binned distribution shown in Figure 2 of Zentner & Bullock (2003), which was designed to match the cosmological N-body simulation results of Ghigna et al (1998), and is similar to the circularity distributions found in more recent N-body analyses (Zentner et al. 2004; Benson 2005).”
Red mergers and the assembly of massive elliptical galaxies: the fundamental plane and its projections (2006, background): “The energy of the bound orbits is taken to correspond to the most probable energy from Benson (2005), which is based on a study of dark matter halo mergers averaged over all cosmological environments.”
Simulations of minor mergers - I. General properties of thick discs (2008, methodology): “(iii) The satellites are released much farther away from the host disk compared to previous studies, and their orbits are consistent with those of infalling substructures in cosmological simulations (e.g., Benson 2005).”
THE UNORTHODOX ORBITS OF SUBSTRUCTURE HALOS (2008, background): “…the past few years, both analytical and numerical, aimed at characterizing the main properties of subhalos, such as their mass function, spatial distribution, and kinematics (e.g. Ghigna et al 1998, 1999; Moore et al 1999; Taylor & Babul 2005a,b; Benson 2005; Gao et al 2004; Diemand et al 2007a,b).”
THE SPACE MOTION OF LEO I: THE MASS OF THE MILKY WAY'S DARK MATTER HALO (2012, background): “…previous ΛCDM-based analyses: Wetzel (2011) finds that the typical infall velocity of satellites for hosts of Mvir ≈ 1012 M is 1.1–1.15 Vvir (see also Benson 2005 and Khochfar & Burkert 2006; the excellent agreement of vtot(rvir) may be partially coincidental, however, as our definition of…”
Ultradiffuse galaxies: the high-spin tail of the abundant dwarf galaxy population (2016, methodology): “…is calculated at the accretion redshift, using rperi = R c 200/2c, where R c 200 is the virial radius of the cluster at that time and c its concentration, so that the resulting rperi is representative of the common cosmological accretion process (e.g., Benson 2005; Wetzel 2011; Jiang et al. 2015).”
The accretion of galaxies into groups and clusters (2009, background): “11, we show the distribution of times for a realistic distribution of infalling dark matter substructure from Benson (2005), randomly sampled 10 000 times.”
Ram pressure stripping the hot gaseous haloes of galaxies in groups and clusters (2007, background): “2 of Benson (2005) to select a range of cosmologically likely orbits; the initial velocity of some orbits is dominated by the radial component while others have nearly circular motions initially3.”
STIRRING UP THE POT: CAN COOLING FLOWS IN GALAXY CLUSTERS BE QUENCHED BY GAS SLOSHING? (2009, background): “Vitvitska et al. (2002) and Benson (2005) examined the tangential and radial components of subcluster velocities over a range of mass ratios.”
Submillimetre galaxies in a hierarchical universe: number counts, redshift distribution, and implications for the IMF (2012, unknown): “For the merger simulations, two of the progenitor disc galaxies are placed on parabolic orbits (which are motivated by cosmological simulations; Benson 2005; Khochfar & Burkert 2006) with initial separation Rinit = 5R200/8 and pericentric-passage distance equal to twice the disc scalelength, Rperi…”
Growth and activity of black holes in galaxy mergers with varying mass ratios (2014, background): “…Van Wassenhove et al. (2014), and to avoid the effects of using different global orbital parameters, we set the galaxies of all encounters to initially follow parabolic orbits (eccentricity e = 1), found to be the most common orbits in cosmological simulations of galaxy formation (Benson 2005).”
The impact of dark matter cusps and cores on the satellite galaxy population around spiral galaxies (2010, methodology): “We must emphasize, however, that these quantities are fairly sensitive to numerical aspects, such as particle number and spatial resolution (e.g. Prugniel & Combes 1992, Wahde & Donner 1996) as well as to the host’s density profile (Hashimoto et al. 2003, Just & Peñarrubia 2005, Read et al. 2006, A”
HOW DO DISKS SURVIVE MERGERS? (2008, background): “Once built, pairs of galaxies are placed on parabolic orbits (motivated by cosmological simulations; see e.g. Benson 2005; Khochfar & Burkert 2006) with the spin axis of each disk specified by the anglesθ and φ in standard spherical coordinates.”
THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE/WFC3 DATA AND ORBIT IMPLICATIONS (2013, background): “Generally, subhalos that are accreted on ∼radial orbits at early times are either preferentially destroyed or exist on more circularized orbits today (e.g., Benson 2005).”
A Fitting Formula for the Merger Timescale of Galaxies in Hierarchical Clustering (2007, methodology): “We do not use the orbital energy as the criterion to identify a satellite as being bound or unbound, since an orbit that starts out unbound will not necessarily remain unbound, because dynamical friction may sufficiently reduce its energy, see e.g., Benson (2005).”
SIMULATIONS OF THE MAGELLANIC STREAM IN A FIRST INFALL SCENARIO (2010, background): “Moreover, these orbits are cosmologically typical (see, e.g., Benson 2005; Wetzel 2010).”
Dynamical friction and galaxy merging time-scales (2007, methodology): “We have covered a range of circularities – 0.3 ≤ η ≤ 1.0 – that includes the most likely values based on analyses of orbits in dark matter simulations (η ≈ 0.5; e.g., Benson 2005; Zentner et al. 2005; Khochfar & Burkert 2006).”
The stellar halo of the Galaxy (2008, methodology): “The satellites are placed on orbits (consistent with those found in cosmological simulations, e.g. Benson (2005)), around a slowly growing gravitational potential that models the Galaxy (resembling the approach of Samland & Gerhard (2003)).”