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  • Gaia and the Galactic Cente...
    Brown, Warren R.; Lattanzi, Mario G.; Kenyon, Scott J.; Geller, Margaret J.

    The Astrophysical journal, 10/2018, Letnik: 866, Številka: 1
    Journal Article

    We use new Gaia measurements to explore the origin of the highest velocity stars in the hypervelocity star (HVS) survey. The measurements reveal a clear pattern in B-type stars. Halo stars dominate the sample at speeds of 100 km s−1 below Galactic escape velocity. Disk runaway stars have speeds up to 100 km s−1 above Galactic escape velocity, but most disk runaways are bound. Stars with speeds 100 km s−1 above Galactic escape velocity originate from the Galactic center. Two bound stars may also originate from the Galactic center. Future Gaia measurements will enable a large, clean sample of Galactic center ejections for measuring the massive black hole ejection rate of HVSs, and for constraining the mass distribution of the Milky Way dark matter halo.