Detection of a dearth of stars with zero angular momentum in the solar neighborhood

Journal Article · Thu Dec 01 04:00:00 EST 2016 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8205/832/2/L25· OSTI ID:22868425

Hunt, Jason A. S.; Bovy, Jo ^[1]; Carlberg, Raymond G. ^[2]

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1. Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)
2. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

We report on the detection in the combined Gaia-DR1/RAVE data of a lack of disk stars in the solar neighborhood with velocities close to zero angular momentum. We propose that this may be caused by the scattering of stars with very low angular momentum onto chaotic, halo-type orbits when they pass through the Galactic nucleus. We model the effect in a Milky Way–like potential and fit the resulting model directly to the data, finding a likelihood (∼2.7σ) of a dip in the distribution. Using this effect, we can make a dynamical measurement of the solar rotation velocity around the Galactic center: v{sub ⊙}=239±9 km s{sup −1}. Combined with the measured proper motion of Sgr A*, this measurement gives a measurement of the distance to the Galactic center: R{sub 0}=7.9±0.3 kpc.

• OSTI ID: 22868425
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 832; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANGULAR MOMENTUM
GALAXY NUCLEI
MILKY WAY
ORBITS
PROPER MOTION
ROTATION
SCATTERING
STARS
VELOCITY