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Related papers: An Alternative Origin for Hypervelocity Stars

200 papers

The most likely origin of hypervelocity stars (HVSs) is the tidal disruption of a binary star by the supermassive black hole (MBH) in the Galactic Centre (GC). However, HE0437-5439, a $9$ M$_\odot$ B-type main-sequence star moving with a…

Astrophysics of Galaxies · Physics 2018-06-27 Giacomo Fragione

We analyze Keck ESI spectroscopy of HVS17, a B-type star traveling with a Galactic rest frame radial velocity of +445 km/s in the outer halo of the Milky Way. HVS17 has the projected rotation of a main sequence B star and is chemically…

Solar and Stellar Astrophysics · Physics 2015-06-16 Warren R. Brown , Judith G. Cohen , Margaret J. Geller , Scott J. Kenyon

Hypervelocity stars (HVSs) represent a unique class of objects capable of escaping the gravitational pull of the Milky Way due to extreme acceleration events, such as close encounters with the supermassive black hole at the Galactic center…

Astrophysics of Galaxies · Physics 2025-04-22 Yongkang Sun , Yang Huang , Jifeng Liu , Haozhu Fu , Huawei Zhang , Yinbi Li , Cuihua Du , Jianrong Shi , Xiao Kong

Hypervelocity stars (HVSs) travel from the Galactic Centre across the dark matter halo of the Milky Way, where they are observed with velocities in excess of the Galactic escape speed. Because of their quasi-radial trajectories, they…

Astrophysics of Galaxies · Physics 2019-06-14 O. Contigiani , E. M. Rossi , T. Marchetti

Observations show the presence, in the halo of our Galaxy, of stars moving at velocities so high to require an acceleration mechanism involving the presence of a massive central black hole. Thus, in the frame of a galaxy hosting a…

Astrophysics of Galaxies · Physics 2015-10-21 R. Capuzzo-Dolcetta , G. Fragione

We measure proper motions with the Hubble Space Telescope for 16 extreme radial velocity stars, mostly unbound B stars in the Milky Way halo. Twelve of these stars have proper motions statistically consistent with zero, and thus have radial…

Solar and Stellar Astrophysics · Physics 2015-06-23 Warren R. Brown , Jay Anderson , Oleg Y. Gnedin , Howard E. Bond , Margaret J. Geller , Scott J. Kenyon

In this paper, we investigate the link between the hypervelocity stars (HVSs) discovered in the Galactic halo and the S-stars moving in the Galactic center (GC), under the hypothesis that they are both the products of the tidal breakup of…

Astrophysics of Galaxies · Physics 2015-06-11 Fupeng Zhang , Youjun Lu , Qingjuan Yu

In recent years several hypervelocity stars (HVSs) have been observed in the halo of our Galaxy. Such stars are thought to be ejected through dynamical interactions near the massive black hole (MBH) in the Galactic center. Three scenarios…

Astrophysics · Physics 2008-12-18 Hagai B. Perets

Hyper-velocity stars (HVS) are moving so fast that they are unbound to the Galaxy. Dynamical ejection by a supermassive black hole is favoured to explain their origin. Locating the place of birth of an individual HVS is of utmost importance…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. Tillich , N. Przybilla , R. -D. Scholz , U. Heber

We use new Gaia measurements to explore the origin of the highest velocity stars in the Hypervelocity Star Survey. The measurements reveal a clear pattern in the B-type stars. Halo stars dominate the sample at speeds about 100 km/s below…

Solar and Stellar Astrophysics · Physics 2018-10-17 Warren R. Brown , Mario G. Lattanzi , Scott J. Kenyon , Margaret J. Geller

We model the fastest moving (v_tot > 300 km/s) local (D < 3 kpc) halo stars using cosmological simulations and 6-dimensional Gaia data. Our approach is to use our knowledge of the assembly history and phase-space distribution of halo stars…

Astrophysics of Galaxies · Physics 2019-03-13 Alis J. Deason , Azadeh Fattahi , Vasily Belokurov , Wyn Evans , Robert J. Grand , Federico Marinacci , Rudiger Pakmor

Utilizing astrometric parameters sourced from \textit{Gaia} Data Release 3 and radial velocities obtained from various spectroscopic surveys, we identify 519 high-velocity stars (HiVels) with a total velocity in the Galactocentric restframe…

Astrophysics of Galaxies · Physics 2024-01-05 Jiwei Liao , Cuihua Du , Mingji Deng , Dashuang Ye , Hefan Li , Yang Huang , Jianrong Shi , Jun Ma

We have discovered a star, SDSS J090745.0+024507, leaving the Galaxy with a heliocentric radial velocity of +853+-12 km/s, the largest velocity ever observed in the Milky Way halo. The star is either a hot blue horizontal branch star or a…

Astrophysics · Physics 2009-11-10 Warren R. Brown , Margaret J. Geller , Scott J. Kenyon , Michael J. Kurtz

Recent Gaia observations suggest that some hypervelocity stars (HVSs) might originate from outside the Galaxy. We ask if these HVSs could come from as far as Andromeda. Therefore, we simulate HVSs originating in Andromeda with initial…

Astrophysics of Galaxies · Physics 2024-04-16 Lukas Gülzow , Malcolm Fairbairn , Dominik J. Schwarz

The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black…

Astrophysics · Physics 2011-05-19 Youjun Lu , Qingjuan Yu , D. N. C. Lin

Hypervelocity stars are those that have speeds exceeding the escape speed and are hence unbound from the Milky Way. We investigate a sample of low-mass hypervelocity candidates obtained using data from the high-precision SDSS Stripe 82…

Astrophysics of Galaxies · Physics 2015-09-25 Yanqiong Zhang , Martin C. Smith , Jeffrey L. Carlin

We explore the possibility that the observed population of Galactic hypervelocity stars (HVSs) originate as runaway stars from the Large Magellanic Cloud (LMC). Pairing a binary evolution code with an N-body simulation of the interaction of…

Astrophysics of Galaxies · Physics 2017-06-21 Douglas Boubert , Denis Erkal , N. W Evans , R. G. Izzard

The last decade has seen the detection of fast moving stars in the Galactic halo, the so-called hypervelocity stars (HVSs). While the bulk of this population is likely the result of a close encounter between a stellar binary and the…

Astrophysics of Galaxies · Physics 2018-01-31 Giacomo Fragione , Alessia Gualandris

Recent observations have found a 1700 km/s star [S5-HVS1] that was ejected from the Galactic Center approximately five million years ago. This star was likely produced by tidal disruption of a binary. In particular, the Galactic Center…

Astrophysics of Galaxies · Physics 2021-02-03 Aleksey Generozov

Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a…