Unified Rotation Curve of the Galaxy — Decomposition into de Vaucouleurs Bulge, Disk, Dark Halo, and the 9-kpc Rotation Dip —

By Yoshiaki Sofue, Y. Sofue, M. Honma, T. Omodaká. 2008

279 citations recorded by the source corpus.

We present a unified rotation curve of the Galaxy re-constructed from the existing data by re-calculating the distances and velocities for a set of galactic constants R0 =8 kpc and V0 =200 km s −1 . We decompose it into a bulge with de Vaucouleurs-law profile of half-mass scale radius 0.5 kpc and mass 1.8 ×10 10 M⊙, an exponential disk of scale radius 3.5 kpc of 6.5 ×10 10 M⊙, and an isothermal dark halo of terminal velocity 200 km s −1 . The r 1/4 -law fit was obtained for the first time for the Milky Way’s rotation curve. After fitting by these fundamental structures, two local minima, or the dips, of rotation velocity are prominent at radii 3 and 9 kpc. The 3-kpc dip is consistent with the observed bar. It is alternatively explained by a massive ring with the density maximum at radius 4 kpc. The 9-kpc dip is clearly exhibited as the most peculiar feature in the galactic rotation curve. We explain it by a massive ring of amplitude as large as 0.3 to 0.4 times the disk density with the density peak at radius 11 kpc. This great ring may be related to the Perseus arm, while no peculiar feature of HI-gas is associated.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/1d10a9fcca36ae7a0bc50031faa9a3557d619024

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Citations in the corpus

History of dark matter (2018, unknown): “…can be constrained using measurements of the Milky Way’s rotation curve (Fich, Blitz, and Stark, 1989; Merrifield, 1992; Dehnen and Binney, 1998; Sofue, Honma, and Omodaka, 2009; Catena and Ullio, 2010; Salucci et al., 2010; Weber and de Boer, 2010; Iocco et al., 2011; Pato, Iocco, and…”
Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy (2016, background): “The total mass of the Galactic bulge is estimated to be ∼ 2 × 1010 M⊙ (Sofue et al. 2009), with a stellar mass ranging somewhere between 1.25 and 1.6×1010 M⊙ (Portail et al. 2015).”
Dark matter direct detection signals inferred from a cosmological N-body simulation with baryons (2009, background): “The mean tangential velocity is 〈vφ〉 = 201 km/s but tends towards 〈vφ〉 = 225 km/s for stars closer to the galactic plane, which is consistent with Milky Way rotation curve data [47].”
`Skinny Milky Way please', says Sagittarius (2014, background): “Once the HI gas gives out beyond ∼ 20 kpc (e.g., Sofue et al. 2009), the rotation curve may continue flat or may decline.”
FORMING REALISTIC LATE-TYPE SPIRALS IN A ΛCDM UNIVERSE: THE ERIS SIMULATION (2011, background): “Its overall shape out to 20 kpc, including the peak in the central bulge-dominated kpc, is reminiscent of the recent reconstruction of the Milky Way rotation curve by Sofue et al. (2009).”
The Aquila comparison project: the effects of feedback and numerical methods on simulations of galaxy formation (2011, background): “…velocity curve of the dark-matter-only Aq-C run (dark solid line) and, for reference, with the rotation curve of the Milky Way as compiled by Sofue et al. (2009).4 This figure makes clear that the ‘best discs’ in terms of morphology (i.e. R-LSFE, R, GAS and G3-GIMIC) all have steeply…”
Dynamical modelling of the galactic bulge and bar: the Milky Way's pattern speed, stellar and dark matter mass distribution (2016, methodology): “Figure 4 shows the rotation curve Vc(r) of these baryonic mass models together with the composite rotation curve from Sofue et al. (2009) rescaled to a distance to the GC and a local circular velocity of (R0,V0) = (8.2kpc,238kms−1) as described in Section 2.2.”
Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way (2019, unknown): “However, there is no evidence for a ≈20 kms−1 dip in the rotation curve near R=9 kpc with a width of ≈2 kpc, as has been suggested in the literature (e.g.,Sofue et al. 2009).”
ON THE SHOULDERS OF GIANTS: PROPERTIES OF THE STELLAR HALO AND THE MILKY WAY MASS DISTRIBUTION (2014, methodology): “…modeling the tidal streams (Law et al. 2005; Newberg et al. 2010; Sanders & Binney 2013b; Sanderson & Helmi 2013), the HI gas rotation curve (e.g. Sofue et al. 2009), fitting a parametrized model to the available observational constraints (e.g. Dehnen & Binney 1998; McMillan 2011; Irrgang et al.…”
The Local Dark Matter Density (2012, background): “Similarly, we neglect the stellar bulge because, as mentioned above, its spatial density atR⊙ is virtually zero (e.g. Sofue et al. 2009).”
The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution (2016, background): “2008; Sofue et al. 2009).”
A new determination of the local dark matter density from the kinematics of K dwarfs (2012, background): “…South Galactic Pole, and using a prior from the rotation curve, Kuijken & Gilmore (1989, 1991) find ρKGdm = 0.010±0.005 M pc−3, consistent with that expected from the rotation curve assuming a spherical Galactic dark matter halo2 (e. g. Sofue et al. 2009; Weber & de Boer 2010; Catena & Ullio 2010).”
The local dark matter density (2014, background): “Global measures extrapolate ρdm from the rotation curve 3 (e.g. Dehnen & Binney, 1998a; Fich et al., 1989; Merrifield, 1992; Sofue et al., 2009; Weber & de Boer, 2010; Catena & Ullio, 2010; McMillan, 2011).”