High-Resolution Measurements of the Halos of Four Dark Matter-Dominated Galaxies: Deviations from a Universal Density Profile

By J. Simon, A. Bolatto, A. Leroy, L. Blitz, E. Gates. 2004

283 citations recorded by the source corpus.

We derive rotation curves for four nearby, low-mass spiral galaxies and use them to constrain the shapes of their dark matter density profiles. This analysis is based on high-resolution two-dimensional Hα velocity fields of NGC 4605, NGC 5949, NGC 5963, and NGC 6689 and CO velocity fields of NGC 4605 and NGC 5963. In combination with our previous study of NGC 2976, the full sample of five galaxies contains density profiles that span the range from αDM = 0 to αDM = 1.20, where αDM is the power-law index describing the central density profile. The scatter in αDM from galaxy to galaxy is 0.44, 3 times as large as in cold dark matter (CDM) simulations, and the mean density profile slope is αDM = 0.73, shallower than that predicted by the simulations. These results call into question the hypothesis that all galaxies share a universal dark matter density profile. We show that one of the galaxies in our sample, NGC 5963, has a cuspy density profile that closely resembles those seen in CDM simulations, demonstrating that while galaxies with the steep central density cusps predicted by CDM do exist, they are in the minority. In spite of these differences between observations and simulations, the relatively cuspy density profiles we find do not suggest that this problem represents a crisis for CDM. Improving the resolution of the simulations and incorporating additional physics may resolve the remaining discrepancies. We also find that four of the galaxies contain detectable radial motions in the plane of the galaxy. We investigate the hypothesis that these motions are caused by a triaxial dark matter halo and place lower limits on the ellipticity of the orbits in the plane of the disk of 0.043-0.175.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/967f97c974e876fa9abaf57b6b8d21d5f343d27a

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Citations in the corpus

Small scale problems of the $\Lambda$CDM model: a short review (2016, methodology): “Top left panel: DM halo RC of NGC5963 (black points with error-bars) computed by [190].”
The Dependence of Halo Clustering on Halo Formation History, Concentration, and Occupation (2005, background): “…LSB galaxies are significantly lower than the standard CDM paradigm predicts (e.g., van den Bosch et al. 2000, 2003a; Debattista & Sellwood 2000; Keeton 2001; van den Bosch & Swaters 2001; Alam et al. 2002; Zentner & Bullock 2002, 2003; McGaugh et al. 2003; Kuhlen et al. 2005; Simon et al. 2005).”
The masses and density profiles of halos in a LCDM galaxy formation simulation (2014, result): “…of cores in real galaxies is still a matter of lively debate, with some authors reporting cores (e.g. Salucci & Burkert 2000; Swaters et al. 2003; Simon et al. 2005; Gentile et al. 2007; de Blok et al. 2008; Kuzio de Naray, McGaugh & de Blok 2008; Oh et al. 2011), others reporting cusps (even…”
Λ Cold Dark Matter, Stellar Feedback, and the Galactic Halo Abundance Pattern (2005, background): “…et al. 2003; Blakeslee et al. 2003; Pen et al. 2003; Lahav et al. 2002; Zehavi et al. 2002), a variety of data on galactic and subgalactic scales has remained more difficult to explain (e.g. Simon et al. 2005; Moore et al. 1999; Klypin et al. 1999; Navarro & Steinmetz 1997, and references therein).”
RECONCILING DWARF GALAXIES WITH ΛCDM COSMOLOGY: SIMULATING A REALISTIC POPULATION OF SATELLITES AROUND A MILKY WAY–MASS GALAXY (2016, background): “…USA 7 Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA, USA 8 Moore Prize Fellow 9 Carnegie Fellow in Theoretical Astrophysics 10 Einstein Fellow cuspy as CDM predicts (e.g., Flores & Primack 1994; Moore 1994; Simon et al. 2005; Oh et al. 2011).”
A METHOD FOR MEASURING (SLOPES OF) THE MASS PROFILES OF DWARF SPHEROIDAL GALAXIES (2011, background): “…measured motions of dynamical tracers in individual galaxies to constrain slopes of the underlying dark matter density profiles (e.g., Moore 1994; Flores & Primack 1994; de Blok & McGaugh 1997; Salucci & Burkert 2000; McGaugh et al. 2001; Simon et al. 2005, de Blok 2010, and references therein).”
NIHAO – IV: core creation and destruction in dark matter density profiles across cosmic time (2015, background): “…for the dark matter seems to be in tension with observations of rotation curves of low mass galaxies (e.g Moore 1994, Salucci & Burkert 2000; Simon et al. 2005; de Blok et al. 2008; Kuzio de Naray, McGaugh & de Blok 2008; Kuzio de Naray, McGaugh & Mihos 2009; Oh et al. 2011a), which seem to…”
The Sloan Lens ACS Survey. IV. The Mass Density Profile of Early-Type Galaxies out to 100 Effective Radii (2007, unknown): “…those predictions to observations with debated results in the case e.g. of low surface brightness galaxies (Salucci 2001; de Blok et al. 2003; Swaters et al. 2003; Gentile et al. 2004; Simon et al. 2005) or at galaxy cluster scales (e.g. Sand et al. 2004; Gavazzi 2005; Comerford et al. 2006).”
Hidden charged dark matter (2009, background): “The status of these discrepancies is unclear — while it seems clear that the census of the observed local group galaxies are broadly in agreement with the cold dark matter model [90, 91], the fit to rotation curves of low-surface brightness galaxies is still problematic [92–96].”
Galactic Searches for Dark Matter (2012, background): “The most dark matter-dominated systems known, whose core sizes are measurable given the scale of modern observations, are the dSphs and the low surface brightness galaxies (Simon et al., 2005; Oh et al., 2011).”
Self-Interacting Dark Matter from a Non-Abelian Hidden Sector (2014, background): “Conversely, observations show that low-surface-brightness spiral galaxies (LSBs) [35–42], satellite dwarf galaxies [41, 43], and galaxy clusters [44–49] exhibit constant-density cores.”
The rotation curves shapes of late-type dwarf galaxies (2009, background): “…al. 2000; van den Bosch et al. 2001; van den Bosch & Swaters 2001; de Blok et al. 2001; Marchesini et al. 2002; de Blok & Bosma 2002, herafter dBB; Swaters et al. 2003a, hereafter SMvdBB; Rhee et al. 2004; Simon et al. 2005; Spekkens et al. 2005; Kuzio de Naray et al. 2006; Chengalur et al. 2008).”
Small-Scale Challenges to the ΛCDM Paradigm (2017, background): “…many (though not all) low-mass dark-matter-dominated galaxies with wellmeasured rotation curves, which prefer fits with constant-density cores (γ ≈ 0 − 0.5; e.g., McGaugh, Rubin & de Blok 2001; Marchesini et al. 2002; Simon et al. 2005; de Blok et al. 2008; Kuzio de Naray, McGaugh & de Blok 2008).”
Galaxy Masses: A Review (2013, unknown): “There is good agreement between resolved rotation curves extracted from Hα, HI and CO lines (Sofue & Rubin 2001; Simon et al. 2003, 2005; Spekkens & Sellwood 2007) and from [OII], [OIII], Hβ, [NII], and [SII] lines (Courteau & Sohn 2003) within the optical disk of galaxies.”
Cosmological Simulations with Self-Interacting Dark Matter I: Constant Density Cores and Substructure (2012, background): “…in the range 50 − 130 km/s, constant-density cores with sizes of∼ 0.5 − 8 kpc and central densities of approximately∼ 0.01 − 0.5M⊙/pc 3 have been observed (de Blok et al. 2001; Simon et al. 2005; Sánchez-Salcedo 2005; Kuzio de Naray et al. 2008, 2010; Oh et al. 2011; Salucci et al. 2012).”
The Core-Cusp Problem (2009, background): “Simon et al. (2005) also derive harmonic decompositions of the velocity fields to study non-circular motions, but they do not list the values of the harmonic coefficients.”