The influence of the secular perturbation of an intermediate-mass companion: II. Ejection of hypervelocity stars from the Galactic Center

Abstract

There is a population of stars with velocities in excess of 500 km s${}^{-1}$ relative to the Galactic center. Many, perhaps most, of these hyper-velocity stars (HVSs) are B stars, similar to the disk and S stars in a nuclear cluster around a super-massive black hole (SMBH) near $\mathrm{Sgr}{\mathrm{A}}^{\star }$. In the paper I of this series, we showed that the eccentricity of the stars emerged from a hypothetical disk around the SMBH can be rapidly excited by the secular perturbation of its intermediate-mass companion (IMC), and we suggested IRS 13E as a potential candidate for the IMC. Here, we show that this process leads to an influx of stars on parabolic orbits to the proximity of $\mathrm{Sgr}{\mathrm{A}}^{\star }$ on a secular timescale of a few Myr. This timescale is much shorter than the diffusion timescale into the lost cone through either the classical or the resonant relaxation. Precession of the highly-eccentric stars' longitude of periastron, relative to that of the IMC, brings them to its proximity within a few Myr. The IMC's gravitational perturbation scatters a fraction of the stars from nearly parabolic to hyperbolic orbits, with respect to the SMBH. Their follow-up close encounters with the SMBH induce them to escape with hyper-velocity. This scenario is a variant of the hypothesis proposed by Hills based on the anticipated breakup of some progenitor binary stars in the proximity of the SMBH, and its main objective is to account for the limited lifespan of the known HVSs. We generalize our previous numerical simulations of this process with a much wider range of orbital configurations. We demonstrate the robustness and evaluate the efficiency of this channel of HVS formation. From these numerical simulations, we infer observable kinematic properties for the HVSs.

arXiv comment17 pages, 10 figures, to be published in ApJ

References in corpus (46)

• A Universal Density Profile from Hierarchical Clustering
• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• Coalescing binary systems of compact objects to (post)$^{5/2}-Newtonian order. V. Spin Effects
• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole: A Paradox of Youth
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• The Stellar Cusp Around the Supermassive Black Hole in the Galactic Center
• The orbit of the star S2 around SgrA* from VLT and Keck data
• Selfgravity and QSO disks
• Stellar disk in the galactic center -- a remnant of a dense accretion disk?
• Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center
• Resonant Relaxation in Stellar Systems
• Discovery of an Unbound Hyper-Velocity Star in the Milky Way Halo
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• A spectroscopic survey on the multiplicity of high-mass stars
• Post-Newtonian Dynamics in Dense Star Clusters: Highly-Eccentric, Highly-Spinning, and Repeated Binary Black Hole Mergers
• Post-Newtonian Dynamics in Dense Star Clusters: Formation, Masses, and Merger Rates of Highly-Eccentric Black Hole Binaries
• Stellar remnants in galactic nuclei: mass segregation
• Greatly enhanced merger rates of compact-object binaries in non-spherical nuclear star clusters
• Hypervelocity Stars: Predicting the Spectrum of Ejection Velocities
• The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared
• Binaries migrating in a gaseous disk: Where are the Galactic center binaries?
• Hypervelocity Stars: From the Galactic Center to the Halo
• The Gravitational Force Field of the Galaxy Measured From the Kinematics of RR Lyrae in Gaia
• Revisiting hypervelocity stars after Gaia DR2
• Secular Stellar Dynamics near a Massive Black Hole
• 3D stellar kinematics at the Galactic center: measuring the nuclear star cluster spatial density profile, black hole mass, and distance
• The First Hypervelocity Star from the LAMOST Survey
• A Black Hole in the Galactic Center Complex IRS 13E?
• Kinematics of hypervelocity stars in the triaxial halo of the Milky Way
• Production of Hypervelocity Stars through Encounters with Stellar-Mass Black Holes in the Galactic Centre
• Ejection of high-velocity stars from the Galactic Center by an inspiraling Intermediate-Mass Black Hole
• Hypervelocity binary stars: smoking gun of massive binary black holes
• Constraints on the Stellar Mass Function from Stellar Dynamics at the Galactic Center
• On the spatial distribution and the origin of hypervelocity stars
• Discovery of two new hypervelocity stars from the LAMOST spectroscopic surveys
• High order symplectic integrators for planetary dynamics and their implementation in REBOUND
• On the number of young stellar discs in the Galactic Centre
• New nearby hypervelocity stars and their spatial distribution from Gaia DR2
• The Second Galactic Center Black Hole?; A Possible Detection of Ionized Gas Orbiting around an IMBH embedded in the Galactic Center IRS13E complex
• Compact-Object Mergers in the Galactic Center: Evolution in Triaxial Clusters
• Planetesimal clearing and size-dependent asteroid retention by secular resonance sweeping during the depletion of the solar nebula
• Clearing residual planetesimals by sweeping secular resonances in transitional disks: a lone-planet scenario for the wide gaps in debris disks around Vega and Fomalhaut
• On the origin of kinematic distribution of the sub-parsec young stars in the Galactic center
• Galactic Center IRS13E: Colliding Stellar Winds or an Intermediate Mass Black Hole?
• The influence of the secular perturbation of an intermediate-mass companion: I. Eccentricity excitation of disk stars at the Galactic center
• Colliding Winds in and around the Stellar Group IRS 13E at the Galactic Center

Cited by in corpus (4)

• Constraints on the Galactic Centre environment from Gaia hypervelocity stars
• Constraints on the Galactic Centre environment from \textit{Gaia} hypervelocity stars III: Insights on a possible companion to Sgr A*
• Constraints on the Galactic Centre environment from Gaia hypervelocity stars II: The evolved population
• Photometric Constraints on Intermediate-mass Black Holes in the Galactic Centre