Strong mass segregation around a massive black hole (2008)
Alexander, Tal, Hopman, Clovis
We show that the mass-segregation solution for the steady state distribution of stars around a massive black hole (MBH) has two branches: the known weak segregation solution (Bahcall & Wolf 1977),...
Resonant relaxation near a massive black hole: the dependence on eccentricity (2007)
Gürkan, M. Atakan, Hopman, Clovis
The orbits of stars close to a massive black hole are nearly Keplerian ellipses. Such orbits exert long term torques on each other, which lead to an enhanced angular momentum relaxation known as...
Massive perturbers in the galactic center (2006)
Perets, Hagai B., Hopman, Clovis, Alexander, Tal
We investigate the role of massive perturbers, such as giant molecular clouds or stellar clusters, in supplying low-angular momentum stars that pass very close to the central massive black hole (MBH)...
Gravitational wave bursts from the Galactic massive black hole (2006)
Hopman, Clovis, Freitag, Marc, Larson, Shane L.
The Galactic massive black hole (MBH), with a mass of Mbh=3.6\times10^6 Solar masses, is the closest known MBH, at a distance of only 8 kpc. The proximity of this MBH makes it possible to observe...
Astrophysics of extreme mass ratio inspiral sources (2006)
Compact remnants on orbits with peri-apses close to the Schwarzschild radius of a massive black hole (MBH) lose orbital energy by emitting gravitational waves (GWs) and spiral in. Scattering with...
Massive perturber-driven interactions of stars with a massive black hole (2006)
Perets, Hagai B., Hopman, Clovis, Alexander, Tal
We study the role of massive perturbers (MPs) in deflecting stars and binaries to almost radial ("loss-cone") orbits, where they pass near the central massive black hole (MBH), interact with it at...
Resonant Relaxation near the Massive Black Hole in the Galactic Center (2006)
Hopman, Clovis, Alexander, Tal
The coherent torques between stars on orbits near massive black holes (MBHs) lead to resonant angular momentum relaxation. Due to the fact that orbits are Keplerian to good approximation, the torques...
Hopman, Clovis, Guetta, Dafne, Waxman, Eli, Zwart, Simon Portegies
Short-hard gamma-ray bursts (SHBs) may arise from gravitational wave (GW) driven mergers of double neutron star (DNS) systems. DNSs may be "primordial" or can form dynamically by binary exchange...
The effect of mass-segregation on gravitational wave sources near massive black holes (2006)
Hopman, Clovis, Alexander, Tal
Gravitational waves (GWs) from the inspiral of compact remnants (CRs) into massive black holes (MBHs) will be observable to cosmological distances. While a CR spirals in, 2-body scattering by field...
Hopman, Clovis, Alexander, Tal
Resonant relaxation (RR) of orbital angular momenta occurs near massive black holes (MBHs) where the stellar orbits are nearly Keplerian and so do not precess significantly. The resulting coherent...
Gravitational waves from remnants of ultraluminous X-ray sources (2005)
Hopman, Clovis, Zwart, Simon Portegies
Ultraluminous X-ray sources (ULXs) with X-ray luminosities larger than the Eddington luminosity of stellar mass objects may be powered by intermediate mass black holes (IBHs) of masses Mbh~10^3Msun....
Hopman, Clovis, Alexander, Tal
We study the orbital parameters distribution of stars that are scattered into nearly radial orbits and then spiral into a massive black hole (MBH) due to dissipation, in particular by emission of...
Ultraluminous X-ray Sources as Intermediate Mass Black Holes Fed by Tidally Captured Stars (2003)
Hopman, Clovis, Zwart, Simon F. Portegies, Alexander, Tal
The nature of ultraluminous X-ray sources (ULXs) is presently unknown. A possible explanation is that they are accreting intermediate mass black holes (IBHs) that are fed by Roche lobe overflow from...
Orbital inspiral into a massive black hole in a galactic center (2003)
Alexander, Tal, Hopman, Clovis
A massive black hole (MBH) in a galactic center drives a flow of stars into nearly radial orbits to replace those it destroyed. Stars whose orbits cross the event horizon r_s or the tidal disruption...