Dark matter and visible baryons in M33

By E. Corbelli. 2003

172 citations recorded by the source corpus.

In this paper we present new measurements of the gas kinematics in M33 using the CO J = 1 - 0 line. The resulting rotational velocities complement previous 21-cm line data for a very accurate and extended rotation curve of this nearby galaxy. The implied dark matter mass, within the total gaseous extent, is a factor of 5 higher than the visible baryonic mass. Dark matter density profiles with an inner cusp as steep as R - 1 , suggested by some numerical simulation of structures formation, are compatible with the actual data. The dark matter concentrations required for fitting the M33 rotation curve are very low but still marginally consistent with haloes forming in a standard cold dark matter cosmology. The M33 virialized dark halo is at least 50 times more massive than the visible baryons and its size is comparable with the M33-M31 separation. Inner cusps as steep as R - 1 . 5 are ruled out, while halo models with a large size core of constant density are consistent with the M33 data. A central excess of stars is needed and we evaluate its dynamical mass range. Using accurate rotational velocity gradients and the azimuthally averaged baryonic surface densities, we show that a disc instability can regulate the star formation activity in M33. Considering the gaseous surface density alone, the predicted outer star formation threshold radius is consistent with the observed drop of the Ha surface brightness if a shear rate criterion is used with the lowest possible value of velocity dispersion. The classical Toomre criterion predicts the size of the unstable region correctly only when the stellar or dark halo gravity, derived in this paper, is added to that of the gaseous disc.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/0ec2b72a8361208647d123b6829ef60ac4a0f79e

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Citations in the corpus

Radial Variation of Attenuation and Star Formation in the Largest Late-Type Disks Observed with GALEX (2006, unknown): “…& van Woerden (1994) ; 13 Carignan & Puche (1990a); 14 Carignan & Puche (1990b) ; 15 Casertano & van Gorkom (1991) ; 16 Cayatte et al. (1994) ; 17 Corbelli (2003) ; 18 Dame et al. (1993) ; 19 Heyer et al. (2004) ; 20 Hunter et al. (2001) ; 21 Jackson et al. (2004) ; 22 Kenney & Young (1988) ; 23…”
ELVIS: Exploring the Local Volume in Simulations (2013, background): “…in McConnachie (2012). k The LMC, from Olsen et al. (2011) l Combining results from Fardal et al. (2013) and van der Marel et al. (2012) who obtain MM31v = (2.1± 1.0)× 10 12 and (1.5± 0.8)× 1012, respectively, with 2-σ errors quoted. m The Triangulum galaxy (M33), from Corbelli (2003) Table 2.”
The Molecular Gas Distribution and Schmidt Law in M33 (2003, methodology): “…H2 gas / P2:2j 1: To evaluate this interplay between the pressure and radiation field, the pressure of a disk in hydrostatic equilibrium is approximated as P ’ 2 G gas gas þ cgas cstar star where star is the star surface density of the disk which best fits the rotation curve (Corbelli 2003, Fig.”
On the correlations between galaxy properties and supermassive black hole mass (2011, background): “The latter is a pure disc galaxy, which does not show any evidence of an SMBH (Gebhardt et al. 2001) but has a massive dark matter halo (Corbelli 2003).”
Molecular and atomic gas in the Local Group galaxy M 33 (2010, result): “…of M33 to the same level as in large spirals, theN(H2)/ICO(1−0) factor would have to be about 3 times the value we use whereas previous studies used even smaller values (Wilson & Scoville 1990; Corbelli 2003; Heyer et al. 2004; Engargiola et al. 2003; Rosolowsky et al. 2007; Gardan et al. 2007).”
A wide-field H I mosaic of Messier 31 - II. The disk warp, rotation, and the dark matter halo (2009, background): “…observational uncertainties on the observed velocities, and the possibility of dark matter compression during the baryonic collapse leave still open the question on how dark matter is effectively distributed in today’s galaxies (van den Bosch et al. 2000; Corbelli 2003; Corbelli & Walterbos 2007).”
THE M31 VELOCITY VECTOR. II. RADIAL ORBIT TOWARD THE MILKY WAY AND IMPLIED LOCAL GROUP MASS (2012, methodology): “Since the data do not reveal a turnover in the rotation curve, both the halo concentration and virial mass are poorly constrained (Figure 6(b) of Corbelli 2003).”
The Local Group on FIRE: dwarf galaxy populations across a suite of hydrodynamic simulations (2018, methodology): “Most notably, the constraint on M33 only represents the mass of the dark matter halo, taken from a fit to CO and H I observations (Simon et al. 2006, using data from Corbelli & Salucci 2000 and Corbelli 2003); including the baryonic component roughly doubles V1/2.”
Giant Molecular Clouds in M33. I. BIMA All-Disk Survey (2003, background): “Accounting for the difference in X factors (Corbelli (2003) used 2.8× 1020cm−2/(K km s−1)), her reported mass is 3 times the value we derive.”
Molecular Hydrogen and Global Star Formation Relations in Galaxies (2007, methodology): “For the M33 galaxy analogue, we used the Heyer et al. (2004) HI and H2 map as guidance for determining the gas distribution with a total gas mass ofMd,g ≈ 1.68× 109h−1M⊙ (Corbelli 2003; Heyer et al. 2004).”