scholarly journals The milky way total mass profile as inferred from Gaia DR2

2020 ◽  
Vol 494 (3) ◽  
pp. 4291-4313 ◽  
Author(s):  
Marius Cautun ◽  
Alejandro Benítez-Llambay ◽  
Alis J Deason ◽  
Carlos S Frenk ◽  
Azadeh Fattahi ◽  
...  
Keyword(s):  
Total Mass ◽  
Rotation Curve ◽  
Milky Way ◽  
Galactic Rotation ◽  
Best Fitting ◽  
Galactic Rotation Curve ◽  
Systematic Biases ◽  
Mass Profile ◽  
Hydrodynamical Simulations ◽  
Gaia Dr2

ABSTRACT We determine the Milky Way (MW) mass profile inferred from fitting physically motivated models to the Gaia DR2 Galactic rotation curve and other data. Using various hydrodynamical simulations of MW-mass haloes, we show that the presence of baryons induces a contraction of the dark matter (DM) distribution in the inner regions, r ≲ 20 kpc. We provide an analytic expression that relates the baryonic distribution to the change in the DM halo profile. For our galaxy, the contraction increases the enclosed DM halo mass by factors of roughly 1.3, 2, and 4 at radial distances of 20, 8, and 1 kpc, respectively compared to an uncontracted halo. Ignoring this contraction results in systematic biases in the inferred halo mass and concentration. We provide a best-fitting contracted NFW halo model to the MW rotation curve that matches the data very well.1 The best-fit has a DM halo mass, $M_{200}^{\rm DM}=0.97_{-0.19}^{+0.24}\times 10^{12}\,\mathrm{M}_\odot$, and concentration before baryon contraction of $9.4_{-2.6}^{+1.9}$, which lie close to the median halo mass–concentration relation predicted in ΛCDM. The inferred total mass, $M_{200}^{\rm total}=1.08_{-0.14}^{+0.20} \times 10^{12}\,\mathrm{M}_\odot$, is in good agreement with recent measurements. The model gives an MW stellar mass of $5.04_{-0.52}^{+0.43}\times 10^{10}\,\mathrm{M}_\odot$ and infers that the DM density at the Solar position is $\rho _{\odot }^{\rm DM}=8.8_{-0.5}^{+0.5}\times 10^{-3}\,\mathrm{M}_\odot \,\mathrm{pc}^{-3}\equiv 0.33_{-0.02}^{+0.02}\,\rm {GeV}\,\rm {cm}^{-3}$. The rotation curve data can also be fitted with an uncontracted NFW halo model, but with very different DM and stellar parameters. The observations prefer the physically motivated contracted NFW halo, but the measurement uncertainties are too large to rule out the uncontracted NFW halo.

scholarly journals The orbital phase space of contracted dark matter haloes

2020 ◽  
Vol 495 (1) ◽  
pp. 12-28 ◽  
Author(s):  
Thomas M Callingham ◽  
Marius Cautun ◽  
Alis J Deason ◽  
Carlos S Frenk ◽  
Robert J J Grand ◽  
...  
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Total Mass ◽  
Milky Way ◽  
Direct Detection ◽  
Baryon Density ◽  
Orbital Phase ◽  
Mass Profile ◽  
Hydrodynamical Simulations ◽  
Radial Action

ABSTRACT We study the orbital phase space of dark matter (DM) haloes in the auriga suite of cosmological hydrodynamics simulations of Milky Way (MW) analogues. We characterize haloes by their spherical action distribution, $F\left(J_{{r}},L\right)$, a function of the specific angular momentum, L, and the radial action, Jr, of the DM particles. By comparing DM-only and hydrodynamical simulations of the same haloes, we investigate the contraction of DM haloes caused by the accumulation of baryons at the centre. We find a small systematic suppression of the radial action in the DM haloes of the hydrodynamical simulations, suggesting that the commonly used adiabatic contraction approximation can result in an underestimate of the density by $\sim 8{{ \rm {per\ cent}}}$. We apply an iterative algorithm to contract the auriga DM haloes given a baryon density profile and halo mass, recovering the true contracted DM profiles with an accuracy of $\sim 15{{ \rm {per\ cent}}}$, that reflects halo-to-halo variation. Using this algorithm, we infer the total mass profile of the MW’s contracted DM halo. We derive updated values for the key astrophysical inputs to DM direct detection experiments: the DM density and velocity distribution in the Solar neighbourhood.

scholarly journals The contribution of the Galactic Bulge to the Galactic rotation curve

1993 ◽  
Vol 153 ◽  
pp. 353-354
Author(s):  
I.V. Petrovskaya ◽  
S. Ninković
Keyword(s):  
Mass Distribution ◽  
Rotation Curve ◽  
Milky Way ◽  
Galactic Rotation ◽  
Galactic Bulge ◽  
Distinct Population ◽  
Gravitation Field ◽  
The Galaxy ◽  
Galactic Rotation Curve

It is not always clear what the bulge of the Galaxy is: a region close to the centre, a subsystem formed by a distinct population, or a mixture of populations but characterised by its own mass distribution. We consider the bulge of the Milky Way as a subsystem and thus contributing to the galactic gravitation field. We want to estimate the contribution of the galactic bulge to the rotation curve.

Galactic rotation curve from the space velocities of selected masers

2011 ◽  
Vol 37 (4) ◽  
pp. 254-266 ◽  
Author(s):  
A. S. Stepanishchev ◽  
V. V. Bobylev
Keyword(s):  
Rotation Curve ◽  
Galactic Rotation ◽  
Galactic Rotation Curve

scholarly journals Milky Way Rotation Models from Neutral Hydrogen and Molecular Clouds: Galactic Constants, Common Details and Differences

2000 ◽  
Vol 174 ◽  
pp. 403-407
Author(s):  
Igor’ I. Nikiforov
Keyword(s):  
Milky Way ◽  
Galactic Center ◽  
Kinematic Model ◽  
Neutral Hydrogen ◽  
Galactic Rotation ◽  
Kinematic Data ◽  
Galactic Rotation Curve ◽  
The Common ◽  
Center Distance

Kinematic data from neutral hydrogen observations provide information to solve the interdependent problems of the determination of the main Galactic constants (the Solar-Galactic center distance R0, the Oort constant A and others) and the Galactic rotation curve (Nikiforov & Petrovskaya 1994, hereafter NP94, and references therein). However, in the standard method for finding R0 by comparing the rotations of HI clouds and some other objects (typically HII regions/CO clouds), the kinematic model, constructed typically solely from HI data, is considered to be the same for both galactic subsystems (e.g. Merrifield 1992). In practice a discrepancy between their rotation curves can produce strongly erroneous results (Merrifield 1992, NP94). Establishing the common rotation law from HI plus HII/CO data in NP94 is only a part of attacking the problem.

Accelerated frames and galactic rotation curves

2019 ◽  
Vol 34 (27) ◽  
pp. 1950218
Author(s):  
S. C. Ulhoa ◽  
F. L. Carneiro
Keyword(s):  
Experimental Data ◽  
General Relativity ◽  
Dark Matter ◽  
Reference Frame ◽  
Rotation Curve ◽  
Reference Frames ◽  
Galactic Rotation ◽  
Inertial Reference Frame ◽  
Galactic Rotation Curve ◽  
Accelerated Frames

In this paper, the galactic rotation curve is analyzed as an effect of an accelerated reference frame. Such a rotation curve was the first evidence for the so-called dark matter. We show another possibility for this experimental data: non-inertial reference frame can fit the experimental curve. We also show that general relativity is not enough to completely explain that which encouraged alternatives paths such as the MOND approach. The accelerated reference frames hypothesis is well-suited to deal with the rotation curve of galaxies and perhaps has some role to play concerning other evidences for dark matter.

scholarly journals The Massive Dark Corona Of Our Galaxy

1996 ◽  
Vol 173 ◽  
pp. 175-176
Author(s):  
K.C. Freeman
Keyword(s):  
Rotation Curve ◽  
Spiral Galaxies ◽  
Galactic Center ◽  
Galactic Disk ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Stellar Component ◽  
The Galaxy ◽  
Galactic Rotation Curve

From their rotation curves, most spiral galaxies appear to have massive dark coronas. The inferred masses of these dark coronas are typically 5 to 10 times the mass of the underlying stellar component. I will review the evidence that our Galaxy also has a dark corona. Our position in the galactic disk makes it difficult to measure the galactic rotation curve beyond about 20 kpc from the galactic center. However it does allow several other indicators of the total galactic mass out to very large distances. It seems clear that the Galaxy does indeed have a massive dark corona. The data indicate that the enclosed mass within radius R increases like M(R) ≈ R(kpc) × 1010M⊙, out to a radius of more than 100 kpc. The total galactic mass is at least 12 × 1011M⊙.

Planetary nebulae and the galactic rotation curve

1983 ◽  
Vol 274 ◽  
pp. L61 ◽  
Author(s):  
S. E. Schneider ◽  
Y. Terzian
Keyword(s):  
Rotation Curve ◽  
Planetary Nebulae ◽  
Galactic Rotation ◽  
Galactic Rotation Curve

scholarly journals The Galactic Rotation Curve to R = 18 Kpc

1980 ◽  
Vol 87 ◽  
pp. 213-220 ◽  
Author(s):  
Leo Blitz ◽  
Michel Fich ◽  
Antony A. Stark
Keyword(s):  
Rotation Curve ◽  
Hii Regions ◽  
Molecular Gas ◽  
Galactic Rotation ◽  
Galactocentric Distance ◽  
The Past ◽  
The Galaxy ◽  
Galactic Rotation Curve ◽  
Sizable Number

The major stumbling block in the determination of a rotation curve beyond the solar circle has been the lack of a suitable set of objects with well defined and independently measured distances and velocities which can be observed to large galactocentric radii. Two things have changed this situation. The first was the realization that essentially all local HII regions have associated molecular material. The second was the acquisition of reliable distances to the stars exciting a sizable number of HII regions at large galactocentric radii (Moffat, FitzGerald, and Jackson 1979). Because the velocity of the associated molecular gas can be measured very accurately by means of radio observations of CO, we have been able to overcome the past difficulties and have measured the rotation curve of the Galaxy to a galactocentric distance of 18 kpc.

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