Dwarf galaxy rotation curves and the core problem of dark matter haloes

By F. V. D. Bosch, R. Swaters. 2000

211 citations recorded by the source corpus.

ABSTRA C T The standard cold dark matter (CDM) model has recently been challenged by the claim that dwarf galaxies have dark matter haloes with constant-density cores, whereas CDM predicts haloes with steeply cusped density distributions. Consequently, numerous alternative dark matter candidates have recently been proposed. In this paper we scrutinize the observational evidence for the incongruity between dwarf galaxies and the CDM model. To this end, we analyse the rotation curves of 20 late-type dwarf galaxies studied by Swaters. Taking the effects of beam smearing and adiabatic contraction into account, we fit mass models to these rotation curves with dark matter haloes with different cusp slopes, ranging from constantdensity cores to r 22 cusps. Even though the effects of beam smearing are small for these data, the uncertainties in the stellar mass-to-light ratio and the limited spatial sampling of the halo’s density distribution hamper a unique mass decomposition. Consequently, the rotation curves in our sample cannot be used to discriminate between dark haloes with constant-density cores and r 21 cusps. We show that the dwarf galaxies analysed here are consistent with CDM haloes in a LCDM cosmology, and that there is thus no need to abandon the idea that dark matter is cold and collisionless. However, the data are also consistent with any alternative dark matter model that produces dark matter haloes with central cusps less steep than r 21.5 . In fact, we argue that based on existing H I rotation curves alone, at best weak limits can be obtained on cosmological parameters and/or the nature of the dark matter. In order to make progress, rotation curves with higher spatial resolution and independent measurements of the mass-to-light ratio of the disc are required.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/1051d3528954e0d652a88e64bbe724053619ee99

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

The rotation curves shapes of late-type dwarf galaxies (2009, background): “This sample forms the basis of the study of the rotation curves of late-type dwarf galaxies presented here (see also Swaters 1999), and of studies of their dark matter properties published earlier (Swaters 1999; van den Bosch & Swaters 2001; SMvdBB).”
Concentration, spin and shape of dark matter haloes as a function of the cosmological model: WMAP1, WMAP3 and WMAP5 results (2008, background): “A more robust approach is to fit a double power-law density profile to the entire rotation curve (e.g., van den Bosch & Swaters 2001, Dutton et al. 2005).”
Dark matter and visible baryons in M33 (2003, methodology): “To estimate any possible ‘beam smearing’ effect we assume that the true velocity, for a given mass model, is that resulting from rotation curve and perform a numerical simulation to derive the observed velocities (van den Bosch & Swaters 2001).”
The Central Mass Distribution in Dwarf and Low Surface Brightness Galaxies (2002, result): “However, slopes withα = 1.5 appear difficult to reconcile with the observations (van den Bosch et al. 2000; Swaters 2001a; van den Bosch & Swaters 2001, hereafter vdBS).”
The First Cosmic Structures and Their Effects (2004, background): “…Brightness Galaxies (LSBGs) and late-type dwarf galaxies (e.g. van den Bosch et al. 2000; Borriello & Salucci 2001; de Blok et al. 2001; van den Bosch & Swaters 2001; de Blok, Bosma & McGaugh 2003; Kleyna et al. 2003), which are sometimes consistent with both a constant density core and an…”
Dark halo response and the stellar initial mass function in early-type and late-type galaxies (2010, background): “There is a well known disk-halo degeneracy that plagues the decomposition of galaxy rotation curves into baryonic and dark matter components (e.g., van Albada & Sancisi 1986; van den Bosch & Swaters 2001; Dutton et al. 2005).”
DARK AND LUMINOUS MATTER IN THINGS DWARF GALAXIES (2010, background): “Of particular interest has been the assumption that the observations suffer from various systematic uncertainties and that the central cusps can be “hidden” this way (Swaters 1999; van den Bosch et al. 2000; van den Bosch & Swaters 2001; Swaters et al. 2003; Simon et al. 2003; Rhee et al. 2004).”
NGC 3741: the dark halo profile from the most extended rotation curve (2006, background): “…the recent past, several studies were devoted to the analysis of rotation curves of dwarf galaxies (e.g. Borriello & Salucci 2001; van den Bosch & Swaters 2001; de Blok, McGaugh & Rubin 2001; de Blok & Bosma 2002; Swaters et al. 2003; Weldrake, de Blok & Walter 2003; Gentile et al. 2005;…”
Formation of isolated dwarf galaxies with feedback (2009, unknown): “The same data, when analysed with different anisotropy assumptions, can therefore result in different density profiles, and as Van den Bosch & Swaters (2001) and Evans et al. (2008) have shown, the stellar kinematics of dwarf spheroidal galaxies are generally not sufficient to distinguish between…”
On the life and death of satellite haloes (2003, background): “Halo profiles of these galaxies likely correspond to the low-concentration satellites studied in this paper (van den Bosch & Swaters 2001) which we have shown are easily disrupted even by the tides of the primary halo alone.”
Bar-driven Dark Halo Evolution: A Resolution of the Cusp-Core Controversy (2001, background): “However, the same analysis used to indicate the lack of a central dark matter cusp also shows that these low surface brightness galaxies are deficient in baryons by three or four times compared to normal galaxies (van den Bosch and Swaters 2001).”
On the frequency, intensity, and duration of starburst episodes triggered by galaxy interactions and mergers (2008, background): “…in the data (such beam smearing, non-circular motion, slit inclinations) could mask the presence of a cusp (van den Bosch et al. 2000; van den Bosch & Swaters 2001; Swaters et al. 2003), suggesting a possible bimodality in the dark halo profiles, with constant density cores restricted to low…”
Formation and Structure of Halos in a Warm Dark Matter Cosmology (2000, background): “…brightness (LSB) galaxies (e.g., Moore 1994 ; Flores & Primack 1994 ; Burkert 1995 ; de Blok & McGaugh 1997 ; de Blok et al. 2001), although other observational studies have challenged this result (van den Bosch et al. 2000 ; Swaters, Madore, & Trewhella 2000 ; van den Bosch & Swaters 2001).”