New dark matter physics: clues from halo structure

By C. Hogan, J. J. Dalcanton. 2000

148 citations recorded by the source corpus.

We examine the effect of primordial dark matter velocity dispersion and/or particle self-interactions on the structure and stability of galaxy halos, especially with respect to the formation of substructure and central density cusps. Primordial velocity dispersion is characterized by a ``phase density'' $Q\ensuremath{\equiv}\ensuremath{\rho}/〈{v}^{2}{〉}^{3/2},$ which for relativistically decoupled relics is determined by particle mass and spin and is insensitive to cosmological parameters. Finite Q leads to small-scale filtering of the primordial power spectrum, which reduces substructure, and limits the maximum central density of halos, which eliminates central cusps. The relationship between Q and halo observables is estimated. The primordial Q may be preserved in the cores of halos and if so leads to a predicted relation, closely analogous to that in degenerate dwarf stars, between the central density and velocity dispersion. Classical polytrope solutions are used to model the structure of halos of collisional dark matter, and to show that self-interactions in halos today are probably not significant because they destabilize halo cores via heat conduction. Constraints on masses and self-interactions of dark matter particles are estimated from halo stability and other considerations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/31baa27a1e771c02fad23669da82be063d838127

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Citations in the corpus

Hierarchical Galaxy Formation and Substructure in the Galaxy’s Stellar Halo (2000, methodology): “Other proposed solutions to the dwarf satellite problem include modifying the inÑationary Ñuctuation spectrum (Kamionkowski & Liddle 2000) or modifying the properties of dark matter by making it warm (WDM; e.g., Hogan & Dalcanton 2000) or self-interacting (SIDM; e.g., Spergel & Steinhardt 2000).”
Halo Cores and Phase-Space Densities: Observational Constraints on Dark Matter Physics and Structure Formation (2000, methodology): “We illustrate this point using two such scenarios for limiting the maximum density of cores in dark matter halos (Hogan & Dalcanton 2000), namely generalized warm collisionless dark matter and warm collisional dark matter.”
Lyman-alpha constraints on warm and on warm-plus-cold dark matter models (2008, background): “This idea was developed in a number of works [26, 27, 28, 29, 30, 31, 32, 33, 25, 34] (for recent results and a critical discussion see [25]).”
Optimized dark matter searches in deep observations of Segue 1 with MAGIC (2013, background): “Furthermore, given their extreme total M/L ratios, it is unlikely that the luminousmaterial has altered the distribution of darkmatter in these systems [203].”
The properties of warm dark matter haloes (2013, background): “…the centres of dark matter haloes, their non-negligible thermal velocities reduce their phase-space density compared to the CDM case and this can result in the formation of a ‘core’ in the density profile whose size varies inversely with the velocity dispersion of the halo (Hogan & Dalcanton 2000).”
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2 (2018, background): “Such cores can naturally arise if the physics of the DM particle is altered (see e.g. Hogan & Dalcanton 2000; Hu, Barkana & Gruzinov 2000; Peebles 2000; Spergel & Steinhardt 2000), but even within cold DM cosmology the inner density profiles of galaxy-hosting haloes can be substantially flattened…”
Cosmological simulations with self-interacting dark matter – II. Halo shapes versus observations (2012, background): “There was a burst of work on SIDM before its untimely demise (Yoshida et al. 2000a,b; Kochanek & White 2000; Hogan & Dalcanton 2000; Dalcanton & Hogan 2001; Davé et al. 2001; Colı́n et al. 2002; Hennawi & Ostriker 2002).”
Halo Substructure and the Power Spectrum (2002, background): “If we define the phase density as Q ≡ ρ/(2πσ2)3/2 then the maximum allowed phase density is (Hogan & Dalcanton 2000) Qmax ≃ 5.2× 10−4 ( mW keV )4( gW 2 ) M⊙/pc 3 (km/s)3 .”
Weakly Self-interacting Dark Matter and the Structure of Dark Halos (2000, background): “Hogan & Dalcanton (2000) considered how the structural properties of halos might scale with their mass. Burkert (2000) and Kochanek &White (2000) studied how collisional relaxation would affect the structure of isolated equilibrium halos, while Moore et al. (2000) and Yoshida et al. (2000)…”
Galactic Searches for Dark Matter (2012, methodology): “Because of the extreme total mass-to-light ratios, it is unlikely that the luminous material has altered the distribution of dark matter in these systems, making them important testbeds for dark matter models (Hogan and Dalcanton, 2000).”
Halo Formation in Warm Dark Matter Models (2000, background): “But the new problems faced by CDM motivate reconsideration of WDM (reincarnated now as ΛWDM) with a view to damping structure on sub-Megaparsec scales (Sommer-Larsen & Dolgov 1999; Hogan & Dalcanton 2000), requiring much lower particle velocities.”
Discovery of a Ringlike Dark Matter Structure in the Core of the Galaxy Cluster Cl 0024+17 (2007, methodology): “The central density profile of Cl 0024+17 has often been used as an argument for self-interacting dark matter (e.g., Spergel & Steinhardt 2000; Hogan & Dalcanton 2000).”
Dwarf galaxy rotation curves and the core problem of dark matter haloes (2000, background): “…scale-invariance (hereafter BSI; Kamionkowski & Liddle 2000; White & Croft 2000), warm dark matter (hereafter WDM; Sommer-Larsen & Dolgov 1999; Hogan & Dalcanton 2000), scalar field dark matter (hereafter SFDM; Peebles & Vilenkin 1999; Hu & Peebles 1999; Peebles 2000; Matos, Siddharta &…”
Repulsive dark matter (2000, background): “If this lengthscale is of order a kiloparsec, as the observations suggest (Hogan & Dalcanton 2000), then the dark matter began to be nonrelativistic at the lowest possible redshift that growth of structure would permit, viz. zrel ∼ zeq.”
Cores in warm dark matter haloes: a Catch 22 problem (2012, background): “Finally the maximum phase space density can be converted in a ’core’ size following Hogan & Dalcanton (2000): r2core,t = √ 3 4πGQmax 1 < σ2halo > 1/2 .”