The Circular Velocity Curve of the Milky Way from 5 to 25 kpc

By Anna-Christina Eilers, David W. Hogg, Hans-Walter Rix, M. Ness. Astrophysical Journal, 2018

286 citations recorded by the source corpus.

We measure the circular velocity curve vc(R) of the Milky Way with the highest precision to date across Galactocentric distances of 5 ≤ R ≤ 25 kpc. Our analysis draws on the six-dimensional phase-space coordinates of ≳23,000 luminous red giant stars, for which we previously determined precise parallaxes using a data-driven model that combines spectral data from APOGEE with photometric information from WISE, 2MASS, and Gaia. We derive the circular velocity curve with the Jeans equation assuming an axisymmetric gravitational potential. At the location of the Sun we determine the circular velocity with its formal uncertainty to be = with systematic uncertainties at the ∼2%–5% level. We find that the velocity curve is gently but significantly declining at (−1.7 ± 0.1) km s−1 kpc−1, with a systematic uncertainty of 0.46 km s−1 kpc−1, beyond the inner 5 kpc. We exclude the inner 5 kpc from our analysis due to the presence of the Galactic bar, which strongly influences the kinematic structure and requires modeling in a nonaxisymmetric potential. Combining our results with external measurements of the mass distribution for the baryonic components of the Milky Way from other studies, we estimate the Galaxy’s dark halo mass within the virial radius to be = and a local dark matter density of = .

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/594c868ffdee5f42dba29eb673846e0817593596

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Citations in the corpus

A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty (2019, methodology): “Several authors studying the Milky Way structure have used this result (McGaugh 2018; Drimmel & Poggio 2018; Mróz et al. 2019; Eilers et al. 2019).”
The milky way total mass profile as inferred from Gaia DR2 (2019, methodology): “Figure 10 shows that the contracted NFW halo model matches well the Eilers et al. (2019) and Callingham et al. (2019b) measurements, which were the ones used for the fitting procedure.”
Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way (2019, result): “Qualitatively, our rotation curve is similar to that presented in the review by Bland-Hawthorn & Gerhard (2016) and more recently in the paper by Eilers et al. (2019) (allowing for their estimate of Q0 of 229 kms−1, which is 7 kms−1 below our value).”
A-type stars in the Canada–France Imaging Survey – II. Tracing the height of the disc at large distances with Blue Stragglers (2018, methodology): “…(Vx, Vy, and Vz) are defined using the conventions adopted in the astropy package (The Astropy Collaboration 2018), with the most recent estimate of the Sun’s position (X = −8.1 kpc; Gravity Collaboration 2018), and with a circular velocity at that position of 229.0 kms−1 (Eilers et al. 2018).”