Halo Cores and Phase-Space Densities: Observational Constraints on Dark Matter Physics and Structure Formation

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

169 citations recorded by the source corpus.

We explore observed trends in the cores of a wide range of relaxed dark matter-dominated halos (about 7 orders of magnitude in mass) to constrain hypothetical dark matter candidates and scenarios of structure formation. First, we argue that neither generic warm dark matter (collisionless or collisional) nor self-interacting dark matter can be responsible for the observed cores on all scales. Both scenarios predict smaller cores for higher mass systems, in conflict with observations; some cores must instead have a dynamical origin. Second, we show that the mean core phase-space densities Q of dwarf spheroidal galaxies, rotating dwarf and low surface brightness galaxies, and clusters of galaxies decrease with increasing velocity dispersion like Q ∝ σ-3 ∝ M-1, as predicted by a simple scaling argument based on quietly merging equilibrium systems over a range of about 8 orders of magnitude in Q. We discuss the processes that set the overall normalization of the observed phase density hierarchy. We note the resemblance between the observed phase-space scaling behavior and density profiles of dark matter halos and stellar components in elliptical galaxies and conjecture that dark matter halos may suffer from the same systematic departures from homology as seen in elliptical galaxies, thus explaining the shallower density profiles observed in low-mass halos. Finally, we use the maximum observed phase-space density in dwarf spheroidal galaxies to fix a minimum mass for relativistically decoupled warm dark matter candidates of roughly 700 eV for thermal fermions and 300 eV for degenerate fermions.

Subfields: Astronomy and Astrophysics, Instrumentation, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/12754ac6da623065f13078cff6934500e84d8fed

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Citations in the corpus

Gravitational probes of dark matter physics (2017, background): “At z ∼ 10, dwarf searches are one of the primary drivers for the upcoming James Webb Space Telescope (JWST) [591, 592], and of major interest for WFIRST.21 The UV luminosity function of galaxies near the epoch of reionization can be an effective probe of power spectrum cutoffs (already excluding the”
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Cosmology and Fundamental Physics with the Euclid Satellite (2012, background): “Self-interacting dark matter (SIDM) changes the expected density distribution within bound dark matter structures [365, 596].”
A lower bound on the mass of dark matter particles (2008, methodology): “It was estimated in [26] that η ≈ 1.”
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A COMPLETE SPECTROSCOPIC SURVEY OF THE MILKY WAY SATELLITE SEGUE 1: THE DARKEST GALAXY (2010, background): “…Diemand, & Madau 2008; Bringmann et al. 2009; Pieri et al. 2009; Martinez et al. 2009) and for placing limits on the phase space density of dark matter particles (e.g., Hogan & Dalcanton 2000; Dalcanton & Hogan 2001; Kaplinghat 2005; Simon & Geha 2007; Strigari et al. 2008b; Geha et al. 2009).”
Does the Fornax dwarf spheroidal have a central cusp or core (2006, background): “Princeton Univ. Press, Princeton, NJ Capuzzo-Dolcetta R., Vicari A., 2005, MNRAS, 356, 899 Chandrasekhar S., 1943, ApJ, 97, 255 Coleman M. G., Da Costa G. S., Bland-Hawthorn J., Freeman K. C., 2005, AJ, 129, 1443 Dalcanton J. J., Hogan C. J., 2001, ApJ, 561, 35 Diemand J., Moore B., Stadel J., 2005,”
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).”
THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. II. THE LARGE MAGELLANIC CLOUD ROTATION FIELD IN THREE DIMENSIONS (2013, background): “Also, central density profile slopes are a powerful probe of the properties of dark matter (Navarro, Frenk, & White et al. 1997; Dalcanton & Hogan 2001), and these can be constrained from observed rotation curves of dwarf galaxies (e.g., de Blok 2010, and references therein; Oh et al. 2011a,b).”