相关论文: Cooling flows and quasars: different aspects of th…
The importance of feedback (radiative and mechanical) from massive black holes at the centers of elliptical galaxies is not in doubt, given the well established relation among black hole mass and galaxy optical luminosity. Here, with the…
We present a physically motivated model for the early co-evolution of massive spheroidal galaxies and active nuclei at their centers. Within dark matter halos, forming at the rate predicted by the canonical hierarchical clustering scenario,…
The current understanding of galaxy formation is that it proceeds in a 'bottom up' way, with the formation of small clumps of gas and stars that merge hierarchically until giant galaxies are built up. The baryonic gas loses the thermal…
In many clusters of galaxies, the cooling time at the core of the intracluster medium is much less than the age of the system, suggesting that the the gas should continually lose energy by radiation. Simple thermodynamic arguments then…
The existence of hot, X-ray luminous gaseous coronae surrounding present day L* galaxies is a generic prediction of galaxy formation theory in the cold dark matter cosmogony. While extended X-ray emission has been known to exist around…
In massive primordial galaxies, the gas may directly collapse and form a single central massive object if cooling is suppressed. Line cooling by molecular hydrogen can be suppressed in the presence of a strong soft-ultraviolet radiation…
Galaxy nuclei are a unique laboratory to study gas flows. High-resolution imaging of the gas flows in galactic nuclei are instrumental in the study of the fueling and the feedback of star formation and nuclear activity in nearby galaxies.…
We present a multi-wavelength study of the interstellar medium in eight nearby, X-ray and optically bright, giant elliptical galaxies. Using Herschel PACS, we map the cold gas in the lines of [CII], [OI], and [OIb]. Additionally, we present…
I begin by summarizing the evidence that there is a close relationship between the evolution of galaxies and supermassive black holes. They evidently share a common fuel source, and feedback from the black hole may be needed to suppress…
We consider the early universe at temperatures close to the fundamental scale of gravity (M_D << M_Planck) in models with extra dimensions. At such temperatures a small fraction of particles will experience transplanckian collisions that…
Expanding X-ray cavities observed in hot gas atmospheres of many galaxy groups and clusters generate shock waves and turbulence that are primary heating mechanisms required to avoid uninhibited radiatively cooling flows which are not…
Using numerical techniques we studied the global stability of cooling flows in giant elliptical galaxies. As an initial equilibrium state we choose the hydrostatic gas recycling model (Kritsuk 1996). Non-equilibrium radiative cooling,…
We study the chemo-dynamical evolution of elliptical galaxies and their hot X-ray emitting gas using high-resolution cosmological simulations. Our Tree N-body/SPH code includes a self-consistent treatment of radiative cooling, star…
The recent {\em ASCA} results show that the iron abundance of the X-ray gas of elliptical galaxies is less than the solar abundance ($Z_{\sun}$). The observed low iron abundance is inconsistent with the predictions of the previous chemical…
The standard treatment of cooling in Cold Dark Matter halos assumes that all of the gas within a ``cooling radius'' cools and contracts monolithically to fuel galaxy formation. Here we take into account the expectation that the hot gas in…
The radiative cooling timescales at the centers of hot atmospheres surrounding elliptical galaxies, groups, and clusters are much shorter than their ages. Therefore, hot atmospheres are expected to cool and to form stars. Cold gas and star…
We study the chemodynamical evolution of elliptical galaxies and their X-ray and optical properties using high-resolution cosmological simulations. Our Tree N-body/SPH code includes a self-consistent treatment of radiative cooling, star…
Black hole accretion flows can be divided into two broad classes: cold and hot. Cold accretion flows, which consist of cool optically thick gas, are found at relatively high mass accretion rates. Prominent examples are the standard thin…
I study the possibility that a cooling flow (CF) exists at the main phase of super massive black hole (SMBH) growth during galaxy formation. To ensure that jets launched by the SMBH efficiently expel gas from the galaxy, as is required by…
We describe 2D gasdynamical models of jets that carry mass as well as energy to the hot gas in galaxy clusters. These flows have many attractive attributes for solving the galaxy cluster cooling flow problem: Why the hot gas temperature and…