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Related papers: Constraining Milky Way mass with Hypervelocity Sta…

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Halo stars with unusually high radial velocity ("hypervelocity" stars, or HVS) are thought to be stars unbound to the Milky Way that originate from the gravitational interaction of stellar systems with the supermassive black hole at the…

Astrophysics · Physics 2009-11-13 Mario G. Abadi , Julio F. Navarro , Matthias Steinmetz

We estimate the mass of the inner ($<20$ kpc) Milky Way and the axis ratio of its dark matter halo using globular clusters as tracers. At the same time, we constrain the phase-space distribution of the globular cluster system. We use the…

Astrophysics of Galaxies · Physics 2019-01-09 Lorenzo Posti , Amina Helmi

We present a new estimate of the mass of the Milky Way, inferred via a Bayesian approach by making use of tracers of the circular velocity in the disk plane and stars in the stellar halo, as from the publicly available {\tt galkin}…

Astrophysics of Galaxies · Physics 2020-05-21 Ekaterina V. Karukes , Maria Benito , Fabio Iocco , Roberto Trotta , Alex Geringer-Sameth

Hypervelocity stars (HVS) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high pass filter preventing low velocity HVS from reaching the halo. To trace the…

Astrophysics · Physics 2009-11-13 S. J. Kenyon , B. C. Bromley , M. J. Geller , W. R. Brown

Hypervelocity stars (HVSs) are a natural consequence of the presence of a massive nuclear black hole (Sgr A*) in the Galactic Center. Here we use the Brown et al. sample of unbound and bound HVSs together with numerical simulations of the…

Astrophysics · Physics 2009-06-23 A. Sesana , F. Haardt , P. Madau

We present a spectroscopic sample of 910 distant halo stars from the Hypervelocity Star survey from which we derive the velocity dispersion profile of the Milky Way halo. The sample is a mix of 74% evolved horizontal branch stars and 26%…

Astrophysics of Galaxies · Physics 2010-07-22 Warren R. Brown , Margaret J. Geller , Scott J. Kenyon , Antonaldo Diaferio

Hypervelocity stars (HVSs) discovered in the Milky Way (MW) halo are thought to be ejected from near the massive black hole (MBH) at the galactic centre. In this paper we investigate the spatial and velocity distributions of the HVSs which…

Astrophysics · Physics 2009-11-13 Blake D. Sherwin , Abraham Loeb , Ryan M. O'Leary

The {\it Gaia} mission has provided the largest catalogue ever of sources with tangential velocity information. However, using this catalogue for dynamical studies is difficult because most of the stars lack line-of-sight velocity…

Astrophysics of Galaxies · Physics 2021-06-02 Helmer H. Koppelman , Amina Helmi

We study the vertical stellar distribution of the Milky Way thin disk in detail with particular focus on the outer disk. We treat the galactic disk as a gravitationally coupled, three-component system consisting of stars, atomic hydrogen…

Astrophysics of Galaxies · Physics 2018-10-03 Suchira Sarkar , Chanda J Jog

In recent years surveys have identified several dozen B stars in the Milky Way halo moving faster than the local escape speed. The origin of most of these hypervelocity stars (HVSs) is still poorly constrained. Here we show that the…

Astrophysics of Galaxies · Physics 2023-01-02 Aleksey Generozov , Hagai B. Perets

We describe our completed spectroscopic survey for unbound hypervelocity stars (HVSs) ejected from the Milky Way. Three new discoveries bring the total number of unbound HVSs to 21. We place new constraints on the nature of HVSs and on…

Solar and Stellar Astrophysics · Physics 2015-06-18 Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

A simple model for the Milky Way halo is presented. It has a flat rotation curve in the inner regions, but the density falls off sharply beyond an outer edge. This truncated, flat rotation curve (TF) model possesses a rich family of simple…

Astrophysics · Physics 2008-11-26 M. I. Wilkinson , N. W. Evans

Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and…

Astrophysics of Galaxies · Physics 2015-05-13 Benjamin C. Bromley , Scott J. Kenyon , Warren R. Brown , Margaret J. Geller

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3-D HI volume density distribution…

Astrophysics · Physics 2009-11-13 P. M. W. Kalberla , L. Dedes , J. Kerp , U. Haud

We measure the circular velocity curve $v_{\rm c}(R)$ of the Milky Way with the highest precision to date across Galactocentric distances of $5\leq R \leq 25$ kpc. Our analysis draws on the $6$-dimensional phase-space coordinates of…

Astrophysics of Galaxies · Physics 2019-03-06 Anna-Christina Eilers , David W. Hogg , Hans-Walter Rix , Melissa Ness

We apply a semi-analytic galaxy formation model to two high resolution cosmological N-body simulations to investigate analogues of the Milky Way system. We select these according to observed properties of the Milky Way rather than by halo…

Astrophysics of Galaxies · Physics 2015-09-30 Qi Guo , Andrew Cooper , Carlos Frenk , John Helly , Wojciech Hellwing

We derive the mass model of the Milky Way (MW) using a cored dark matter (DM) halo profile and recent data. The method used consists in fitting a spherically symmetric model of the Galaxy with a Burkert DM halo profile to available data: MW…

Astrophysics of Galaxies · Physics 2015-06-15 Fabrizio Nesti , Paolo Salucci

Despite the Milky Way's proximity to us, our knowledge of its dark matter halo is fairly limited, and there is still considerable uncertainty in its halo mass. Many past techniques have been limited by assumptions such as the Galaxy being…

Astrophysics of Galaxies · Physics 2024-04-09 Elaheh Hayati , Peter Behroozi , Ekta Patel

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 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