Mass models of the Milky Way

By P. McMillan. 2011

567 citations recorded by the source corpus.

We present a simple method for fitting parametrized mass models of the Milky Way to observational constraints. We take a Bayesian approach which allows us to take into account input from photometric and kinematic data, and expectations from theoretical modelling. This provides us with a best-fitting model, which is a suitable starting point for dynamical modelling. We also determine a probability density function on the properties of the model, which demonstrates that the mass distribution of the Galaxy remains very uncertain. For our choices of parametrization and constraints, we find disc scalelengths of 3.00 ± 0.22 and 3.29 ± 0.56 kpc for the thin and thick discs, respectively, a solar radius of 8.29 ± 0.16 kpc and a circular speed at the Sun of 239 ± 5 km s−1, a total stellar mass of 6.43 ± 0.63 × 1010 M⊙, a virial mass of 1.26 ± 0.24 × 1012 M⊙ and a local dark matter density of 0.40 ± 0.04 GeV cm−3. We find some correlations between the best-fitting parameters of our models (for example, between the disc scalelengths and the solar radius), which we discuss. The chosen disc scaleheights are shown to have little effect on the key properties of the model.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/ceb3f98dd459c3bc8b4a762505ef378b8eacc36f

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Citations in the corpus

IMPROVED ESTIMATES OF THE MILKY WAY’S STELLAR MASS AND STAR FORMATION RATE FROM HIERARCHICAL BAYESIAN META-ANALYSIS (2014, background): “Given our prior understanding of the total mass of the Milky Way to be of order 5 1010∼ × M⊙ (e.g., McMillan 2011 and references therein) we assume the mass of the Galactic bulge can be anywhere in the range 0–4 × 1010 M⊙ with equal weighting.”
The merger rate of galaxies in the Illustris simulation: a comparison with observations and semi-empirical models (2015, background): “For example, the major merger rate at z ≈ 0.1 (blue line, upper left panel) for Milky Way-like galaxies with M∗ ≈ 6 × 1010 M (McMillan 2011) is slightly larger than 0.02 Gyr−1, which means that roughly one in every 50 Milky Way-like galaxies has undergone a major merger during the last Gyr.”
COSMIC Variance in Binary Population Synthesis (2019, methodology): “Following McMillan (2011), we assume the mass in the thin and thick disks to be 4.32 × 1010M and 1.44 × 1010M respectively, while we assume the mass of the bulge to be 8.9× 109M .”
The bifurcated age–metallicity relation of Milky Way globular clusters and its implications for the accretion history of the galaxy (2013, methodology): “Since the MW disk has a mass of ∼ (3± 1)× 1010M Robin et al. (2003); McMillan (2011), this implies that the halo GCs are described by an AMR that is representative of 3 We note that the slope and differential shape of both the gaseous and stellar MMR in the mass range of interest are nearly…”
INTEGRAL constraints on primordial black holes and particle dark matter (2020, methodology): “We take a scale radius rh = 17 kpc for the MW halo [66].”
THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE/WFC3 DATA AND ORBIT IMPLICATIONS (2013, methodology): “McMillan (2011) has presented a Milky Way analysis that includes all relevant observational constraints, from which he derived V0 = 239 ± 5 km s−1 .”
THE SIZE–VIRIAL RADIUS RELATION OF GALAXIES (2012, methodology): “I 4 Stellar masses in all of the samples were estimated assuming the Chabrier (2003) IMF. also include the stellar mass profile of the Milky Way using a combination of thin and thick stellar disks with parameters given in Table 2 of McMillan (2011).”
Impacts of a flaring star-forming disc and stellar radial mixing on the vertical metallicity gradient (2016, unknown): “The halo mass is roughly consistent with the recent estimated mass of the Milky Way (e.g. McMillan 2011).”
THE SINFONI BLACK HOLE SURVEY: THE BLACK HOLE FUNDAMENTAL PLANE REVISITED AND THE PATHS OF (CO)EVOLUTION OF SUPERMASSIVE BLACK HOLES AND BULGES (2016, methodology): “Using the spherically averaged density profile of McMillan (2011) we get a mass within this radius of 7.2 × 109M , so we scale up this profile by a factor 2.54.”
The milky way total mass profile as inferred from Gaia DR2 (2019, methodology): “Most studies assume that the DM halo is well described by an NFW profile (Navarro et al. 1996, 1997) and constrain the profile by two parameters, such as total mass and concentration (e.g. McMillan 2011; Bovy et al. 2012; Eilers et al. 2019).”
The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars (2015, background): “2 shows that the stellar mass of a Milky Way-sized galaxy with M∗ ≈ 6 × 1010M (McMillan 2011) grows by ∼1 per cent per Gyr due to mergers (of any mass ratio) at z ≈ 0.1, but at the same time grows by ∼10 per cent per Gyr due to in situ star formation, which is the dominating factor for galaxies of…”
A DIRECT DYNAMICAL MEASUREMENT OF THE MILKY WAY'S DISK SURFACE DENSITY PROFILE, DISK SCALE LENGTH, AND DARK MATTER PROFILE AT 4 kpc ≲ R ≲ 9 kpc (2013, methodology): “(6) Binney (2012a) discusses how the choice of ∆ influences the precision with which the actions are calculated.”
THE M31 VELOCITY VECTOR. II. RADIAL ORBIT TOWARD THE MILKY WAY AND IMPLIED LOCAL GROUP MASS (2012, methodology): “This distribution has the same mean (1.50 × 1012 M ) as inferred by McMillan (2011), and the same dispersion (0.43 × 1012 M ) as we use for M31, but with a broader, flatter shape.9 We use the listed probability distributions for the individual M31 and MW masses as priors; this also sets a prior…”
Type-Ia Supernova Rates and the Progenitor Problem: A Review (2011, background): “In the solar neighborhood the ratio of stellar mass to WD number is 18.5 M⊙/WD (based on the local stellar mass density, 0.085M⊙ pc −3, McMillan 2011; and the local WD number density, 0.0046 pc−3, Harris et al. 2006).”
The RAVE survey : the Galactic escape speed and the mass of the Milky Way (2013, background): “McMillan (2011) find an intermediate mass of 1.3 × 1012 M , including constraints from photometric data.”
Reconstructing the star formation history of the Milky Way disc(s) from chemical abundances (2014, background): “The mean SFH in the thin disc phase (age 7 Gyr) is compatible with a constant SFR at the level of 4.7 solar masses per year if our total SFH is normalized to the total Milky Way stellar mass from McMillan (2011).”