相关论文: Supermassive galactic centre with repulsive gravit…
We present a high resolution simulation of an idealized model to explain the origin of the two young, counter-rotating, sub-parsec scale stellar disks around the supermassive black hole SgrA* at the Center of the Milky Way. In our model,…
In this contribution, we revisit the model of a dust-enshrouded star orbiting a low-luminosity galactic nucleus (Zaja\v{c}ek et al. 2014, 2016, 2017). Although it is quite challenging for dust to survive in hot X-ray-emitting plasma…
We use cosmological hydrodynamical simulations to show that a significant fraction of the gas in high redshift rare massive halos falls nearly radially to their very centre on extremely short timescales. This process results in the…
The existence of supermassive black holes lurking in the centers of galaxies and of stellar binary systems containing a black hole with a few solar masses has been established beyond reasonable doubt. The idea that black holes of…
The origin of supermassive black holes (SMBHs) that inhabit the centers of massive galaxies is largely unconstrained. Remnants from supermassive stars (SMSs) with masses around 10,000 solar masses provide the ideal seed candidates, known as…
A star burns its nuclear fuel and balances gravitation by the pressure of the heated gas, during its active lifetime. After the exhaustion of the nuclear fuel, a low mass star finds peace as a {\em white dwarf}, where the pressure support…
We study of the collapse of a magnetized spherical star to a black hole in general relativity theory. The matter and gravitational fields are described by the exact Oppenheimer-Snyder solution for the collapse of a spherical, homogeneous…
We have recently proposed a model for a regular black hole, or an ultra-compact object, that is premised on having maximally negative radial pressure throughout the entirety of the object's interior. This model can be viewed as that of a…
A natural consequence of the galaxy formation paradigm is the existence of supermassive black hole (SMBH) binaries. Gravitational perturbations from a far-away SMBH companion can induce high orbital eccentricities on dark matter particles…
We study the observational constraints on the cosmic evolution of the relationships between the massive black hole (MBH) mass (M_bh) and the stellar mass (M^*_sph; or velocity dispersion \sigma) of the host galaxy/spheroid. Assuming that…
We study the spherically symmetric collapse of a cloud of dust in VCDM, a class of gravitational theories with two local physical degrees of freedom. We find that the collapse corresponds to a particular foliation of the Oppenheimer-Snyder…
The region bounded by the inner tens of light years at the center of the Milky Way contains five principal components that coexist within the central deep gravitational potential well. These constituents are a black hole candidate (Sgr~A*)…
The Schwarzschild metric has a divergent energy density at the horizon, which motivates a new approach to black holes. If matter is spread uniformly throughout the interior of a supermassive black hole, with mass $M\sim M_\star= 2.34…
Understanding the connection between galaxy properties and their central massive black holes (MBHs) is key to unveiling their co-evolution. We use the ${\tt L{-}Galaxies{-} \it BH}$ semi-analytical model and the ${\tt Millennium}$ suite of…
Most galactic nuclei are now believed to harbour supermassive black holes. Studies of stellar motions in the central few light-years of our Milky Way Galaxy indicate the presence of a dark object with a mass of about 2.6 million solar…
For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near…
The galactic black hole is a supermassive black hole located at the center of a galaxy surrounded by a dark matter halo. For the first time, we establish a generic, fully-relativistic formalism to calculate solutions of Einstein's gravity…
Supermassive black holes dominate the gravitational potential in galactic nuclei. In these dense environments, stars follow nearly Keplerian orbits and see their orbital planes relax through the potential fluctuations generated by the…
This study explores the effect of charge on a special astronomical object known as a gravastar, which is viewed as an alternative to a black hole. Based on the conjecture put out by Mazur and Mottola in general relativity, the study…
Direct observation of black holes is one of the grand challenges in astronomy. If there are super-compact objects which possess unstable circular orbits of photons, however, it may be difficult to distinguish them from black holes by…