Does the Fornax dwarf spheroidal have a central cusp or core

By T. Goerdt, B. Moore, Justin I. Read, Joachim Stadel, Marcel Zemp, U. Zurich, E. Zurich. 2006

213 citations recorded by the source corpus.

ABSTRACT The dark matter dominated Fornax dwarf spheroidal has ﬁve globular clusters orbitingat ∼ 1kpc from its centre. In a cuspy CDM halo the globulars would sink to thecentre from their current positions within a few Gyrs, presenting a puzzle as to whythey survive undigested at the present epoch. We show that a solution to this timingproblem is to adopt a cored dark matter halo. We use numerical simulations andanalytic calculations to show that, under these conditions, the sinking time becomesmany Hubble times; the globulars eﬀectively stall at the dark matter core radius. Weconclude that the Fornax dwarf spheroidal has a shallow inner density proﬁle with acore radius constrained by the observed positions of its globular clusters. If the phasespace density of the core is primordial then it implies a warm dark matter particleand gives an upper limit to its mass of ∼ 0.5keV, consistent with that required tosigniﬁcantly alleviate the substructure problem.Keywords: galaxies:starclusters — galaxies:dwarfs— galaxies:individual (Fornax)methods: N-body simulations

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0b4f2a29e936522aa40d37a841145a9c39e92d4a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Understanding the shape and diversity of dwarf galaxy rotation curves in ΛCDM (2016, methodology): “6 Note that the true ‘size’ of the dark matter core is somewhat arbitrary and depends on what definition we use (see e.g. the discussion in Goerdt et al. 2006).”
WHY BARYONS MATTER: THE KINEMATICS OF DWARF SPHEROIDAL SATELLITES (2012, background): “It has also been argued that the fact that Fornax’s globular cluster orbits have not decayed by dynamical friction requires a cored DM profile (Goerdt et al. 2006; Cole et al. 2012).”
Empirical Models for Dark Matter Halos. II. Inner Profile Slopes, Dynamical Profiles, and ρ/σ3 (2006, background): “De Blok (2005) has argued that the inner profile slopes of simulated, dark matter halos are inconsistent with observations of dark matter dominated galaxies (Moore et al. 1999; Salucci & Burkert 2000; Marchesini et al. 2002; de Blok, Bosma, & McGaugh 2003; Gentile et al. 2006; Goerdt et al. 2006).”
A METHOD FOR MEASURING (SLOPES OF) THE MASS PROFILES OF DWARF SPHEROIDAL GALAXIES (2011, background): “…dark matter to rapid baryonic outflows (e.g., Read & Gilmore 2005; Mashchenko et al. 2006, 2008; de Souza et al. 2011) or the transfer of energy and/or angular momentum to the dark matter from massive infalling objects (e.g., Sánchez-Salcedo et al. 2006; Goerdt et al. 2006, 2010; Cole et al. 2011).”
Dark matter cores and cusps: the case of multiple stellar populations in dwarf spheroidals (2011, background): “Second, Goerdt et al. (2006) and Sánchez-Salcedo et al. (2006) studied the five globular clusters present in the Fornax dSph, which orbit at projected radii ∼ 1 kpc from the centre.”
Dark matter annihilation and decay in dwarf spheroidal galaxies: the classical and ultrafaint dSphs (2015, background): “…dSphs with good data favour dark matter cores over the cusps predicted by pure cold dark matter cosmological simulations (e.g. Kleyna et al. 2003; Goerdt et al. 2006; Battaglia et al. 2008; Walker & Peñarrubia 2011; Cole et al. 2012; Agnello & Evans 2012; Amorisco, Agnello & Evans 2013), though…”
THE NUCLEUS OF THE SAGITTARIUS DSPH GALAXY AND M54: A WINDOW ON THE PROCESS OF GALAXY NUCLEATION (2008, background): “…prevent the further decay of other clusters (that, in general cases, would be quite difficult, given the expected decay times, see Hernandez & Gilmore 1998; Oh, Lin & Richer 2000; Read et al. 2006; Sánchez-Salchedo, Reyes-Iturbide & Hernandez 2006; Goerdt et al. 2006, and references therein).”
Extragalactic Globular Clusters and Galaxy Formation (2006, methodology): “Goerdt et al. (2006) have used numerical simulations to show that the dynamical friction timescale in Fornax is longer than a Hubble time if its dark matter halo has a core (instead of the cusp generically predicted in galaxy formation in ΛCDM).”
The Orbital Poles of Milky Way Satellite Galaxies: A Rotationally Supported Disk of Satellites (2008, background): “In a series of papers, Piatek et al. (2003, 2005, 2006, 2007) measured the proper motions of the dSph galaxies Carina, Ursa Minor, Sculptor, and Fornax, respectively, with the Hubble Space Telescope (HST ).”
Ultralight scalars as cosmological dark matter (2016, background): “This effect, sometimes called “core stalling”, is seen in a variety of N-body simulations [75, 136, 137] but the physics behind it remains murky [136, 138, 139].”
Dark matter cores all the way down (2015, background): “This can be avoided if there is a central constant density core that causes dynamical friction to stall (Goerdt et al. 2006; Read et al. 2006a).”
Cuspy No More: How Outflows Affect the Central Dark Matter and Baryon Distribution in Lambda CDM Galaxies (2012, background): “…through SN feedback or dynamical friction (Navarro et al. 1996a; Dekel et al. 2003b,a; Mo & Mao 2004; Read & Gilmore 2005; Mashchenko et al. 2006; Goerdt et al. 2006; Tonini et al. 2006; El-Zant et al. 2004; Romano-Dı́az et al. 2009; Del Popolo 2009; Lackner & Ostriker 2010; Goerdt et al.…”
CONSTRAINTS ON MACHO DARK MATTER FROM COMPACT STELLAR SYSTEMS IN ULTRA-FAINT DWARF GALAXIES (2016, background): “At MACHO masses &100 M⊙, Hernández et al. (2004) showed that some dwarf galaxy cores would be dynamically relaxed, in tension with the relatively constant-density cores that have been inferred (Sánchez-Salcedo et al. 2006; Goerdt et al. 2006).”