相关论文: SEGUE-2 Limits on Metal-Rich Old-Population Hyperv…

We present limits on the ejection of old-population HVS from a sample of over 290,000 stars selected from the SDSS. We derive the speed at the solar circle from the measured positions and radial velocities by assuming a radial orbit and…

Dynamical interactions between stars and the super massive black hole Sgr A* at the Galactic Centre (GC) may eject stars into the Galactic halo. While recent fast ejections by Sgr A* have been identified in the form of hypervelocity stars…

We study three processes that eject hypervelocity (>10^3 km/s) stars from the Galactic center: (i) close encounters of two single stars; (ii) tidal breakup of binary stars by the central black hole, as originally proposed by Hills; and…

We estimate the distribution of ejection velocities for the known population of high galactic latitude runaway stars. The initial sample is a collection of 174 early-type stars selected from the literature. The stars are first classified…

A dynamical encounter between a stellar binary and Sgr A* in the Galactic Centre (GC) can tidally separate the binary and eject one member with a velocity beyond the escape speed of the Milky Way. These hypervelocity stars (HVSs) can offer…

We present 20 candidate hypervelocity stars from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) G and K dwarf samples. Previous searches for hypervelocity stars have only focused on large radial velocities; in this…

Hypervelocity stars are believed to be ejected out from the Galactic center through dynamical interactions of (binary) stars with the central massive black hole(s). In this letter, we report 13 metal-poor F-type hypervelocity star…

We report the discovery of 3 new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their only suggested origin. We also detect a population of…

We report the discovery of 30 stars with extreme space velocities ($>$ 480 km/s) in the Gaia-DR2 archive. These stars are a subset of 1743 stars with high-precision parallax, large tangential velocity ($v_{tan}>$ 300 km/s), and measured…

The disruption of binary stars by the tidal field of the black hole in the Galactic Center can produce the hypervelocity stars observed in the halo. We use numerical models to simulate the full spectrum of observable velocities of stars…

The dense cores of Milky Way globular clusters (GCs) play host to a variety of dynamical encounters between stellar objects, which can accelerate stars to velocities high enough to escape the GC. The most extreme examples of these…

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…

Following a dynamical encounter with Sgr A*, binaries in the Galactic Centre (GC) can be tidally separated and one member star ejected as a hyper-velocity star (HVS) with a velocity beyond the escape speed of the Milky Way. As GC-born…

Gas expulsion is a central concept in some of the models for multiple populations and the light-element anticorrelations in globular clusters. If the star formation efficiency was around 30 per cent and the gas expulsion happened on the…

To date, all of the reported high velocity stars (HVSs), which are believed to be ejected from the Galactic center, are blue and therefore almost certainly young. Old-population HVSs could be much more numerous than the young ones that have…

Hyper-velocity stars are believed to be ejected out from the Galactic center through dynamical interactions between (binary) stars and the central massive black hole(s). In this paper, we report 19 low mass F/G/K type hyper-velocity star…

Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic observations from our targeted survey for HVSs. We…

Hypervelocity stars (HVS) move so fast that they are unbound to the Galaxy. When they were first discovered in 2005, dynamical ejection from the supermassive black hole (SMBH) in the Galactic Centre (GC) was suggested as their origin. The…

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…

The discovery of hypervelocity binary stars (HVBs) in the Galactic halo would provide definite evidence of the existence of a massive black hole companion to Sgr A*. Here we use an hybrid approach to compute the rate of ejection and the…