相关论文: Donald Lynden-Bell: A Biographical Memoir
Since Stephen Hawking discovered that black holes emit thermal radiation, black holes have become the theoretical laboratories for testing our ideas on quantum gravity. This dissertation is devoted to the study of singularities, the…
The main challenge for understanding the fuelling of supermassive black holes in active galactic nuclei is not to account for the source of fuel, but rather to explain its delivery from the boundaries of the black hole sphere of influence…
1) Rotation Curves and M/L Evolution for Galaxies to z=0.4, (Bershady, Haynes, Giovanelli, & Andersen) 2) Mass Estimates of Starbursting Galaxies: Line Widths versus Near-IR Luminosities (Jangren, Bershady, & Gronwall) 3) Galaxy Kinematics…
Tidal disruption events (TDEs) take place when a star ventures too close to a supermassive black hole (SMBH) and becomes ruptured. One of the leading proposed physical mechanisms often invoked in the literature involves weak two-body…
Stationary, axisymmetric, dust sourced solutions of Einstein's equations have been proposed as fully general relativistic models for disc galaxies. These models introduce a novel physical element, i.e., a non-negligible dragging vortex…
Using parsec-resolution simulations of a typical galaxy merger, we study the triggering of starbursts by connecting the (inter-)galactic dynamics to the structure of the interstellar medium. The gravitational encounter between two galaxies…
The dark matter halos in $\Lambda$CDM cosmological simulations are triaxial and highly flattened. In many cases, these triaxial equilibria are also tumbling slowly, typically about their short axes, with periods of order a Hubble time.…
While the LCDM framework has been incredibly successful for modern cosmology, it requires the admission of two mysterious substances as a part of the paradigm, dark energy and dark matter. Although this framework adequately explains most of…
We derive the radial acceleration of stars in galaxies by using basic features of thermodynamics, statistical mechanics and general relativity. We assume that the "dark" component of the radial acceleration is originated from the reaction…
We propose an approximate approach for studying the relativistic regime of stellar tidal disruptions by rotating massive black holes. It combines an exact relativistic description of the hydrodynamical evolution of a test fluid in a fixed…
High-resolution observations from the sub-mm to the optical wavelength regime resolve the central few 100pc region of nearby galaxies in great detail. They reveal a large diversity of features: thick gas and stellar discs, nuclear…
Geometrically thick disks may form after tidal disruption events, and rapid accretion may lead to short flares followed by long-term, lower-level emission. Using a novel accretion disk code which relies primarily on global conservation laws…
Origin of turbulence in cold accretion disks, particularly in 3D, which is expected to be hydrodynamic but not magnetohydrodynamic, is a big puzzle. While the flow must exhibit some turbulence in support of the transfer of mass inward and…
(doctoral thesis of Michal Bilek, finished on June 19, 2015) MOND is an observational rule for predicting the acceleration of stars and galaxies from the distribution of the visible matter. It possibly stems from a new law of physics. I…
It has been suggested that star-forming galaxies may host a substantial, dark reservoir of gas in the form of planetary-mass molecular clouds that are so cold that $\text{H}_{2}$ can condense. Here we investigate the process of tidal…
This is our first study of the magnetic Rayleigh-Taylor instability at the inner edge of an astrophysical disk around a central back hole. We derive the equations governing small-amplitude oscillations in general relativistic ideal…
Binary black holes occupy a special place in our quest for understanding the evolution of galaxies along cosmic history. If massive black holes grow at the center of (pre-)galactic structures that experience a sequence of merger episodes,…
We investigate the properties of spiral shocks in a steady, adiabatic, non-axisymmetric, self-gravitating, mass-outflowing accretion disk around a compact object. We obtain the accretion-ejection solutions in a gaseous galactic disk and…
We review some of the interesting consequences that tilts, warps, and eccentricities can introduce into the dynamics, thermodynamics, and observational appearance of accreting systems, with an emphasis on disks around black holes and…
Galaxies are surrounded by large halos of hot gas which must be replenished as the gas cools. This led Norman & Ikeuchi (1989) to propose the chimney model of the interstellar medium, which predicts that there should be on the order of a…