Related papers: Adding Environmental Gas Physics to the Semi-Analy…
Evaluation of gravitational theories by means of cosmological data suffers from the fact that galaxies are biased tracers of dark matter. Current bias models focus primarily on high-density regions, whereas low-density regions carry…
We construct the Numerical Galaxy Catalog ($\nu$GC), based on a semi-analytic model of galaxy formation combined with high-resolution N-body simulations in a $\Lambda$-dominated flat cold dark matter ($\Lambda$CDM) cosmological model. The…
Galaxy clusters are the most massive collapsed structures in the universe whose potential wells are filled with hot, X-ray emitting intracluster medium. Observations however show that a significant number of clusters (the so-called…
Observed rotation curves in star-forming galaxies indicate a puzzling dearth of dark matter in extended flat cores within haloes of mass $\geq\! 10^{12}M_\odot$ at $z\!\sim\! 2$. This is not reproduced by current cosmological simulations,…
We present numerical methods for including stellar feedback in galaxy-scale simulations. We include heating by SNe (I & II), gas recycling and shock-heating from O-star & AGB winds, HII photoionization, and radiation pressure from stellar…
We implement physically motivated recipes for partitioning cold gas into different phases (atomic, molecular, and ionized) in galaxies within semi-analytic models of galaxy formation based on cosmological merger trees. We then model the…
We explore the effect of active galactic nucleus (AGN) feedback from central galaxies on their satellites by comparing two sets of cosmological zoom-in runs of 27 halos with masses ranging from $10^{12}$ to $10^{13.4}$ solar masses at z=0,…
Feedback heating from AGN in massive galaxies and galaxy clusters can be thought of as a naturally occurring control system which plays a significant role in regulating both star formation rates and the X-ray luminosity of the surrounding…
Feedback is indispensable in galaxy formation. However, lacking resolutions, cosmological simulations often use ad hoc feedback parameters. Conversely, small-box simulations, while better resolving the feedback, cannot capture gas evolution…
We consider non-gravitational heating effects on galaxy clusters on the basis of the Monte-Carlo modeling of merging trees of dark matter halos combined with the thermal evolution of gas inside each halo. Under the assumption of hydrostatic…
We compare two techniques for following the cooling of gas and its condensation into galaxies within high resolution simulations of cosmologically representative regions. Both techniques treat the dark matter using N-body methods. One…
Unopposed radiative cooling in clusters of galaxies results in excessive mass deposition rates. However, the cool cores of galaxy clusters are continuously heated by thermal conduction and turbulent heat diffusion due to minor mergers or…
We use a semi-analytic model of galaxy formation to study signatures of large-scale modulations in the star formation (SF) activity in galaxies. In order to do this we carefully define local and global estimators of the density around…
We have updated our radially-resolved SAMs of galaxy formation, which track both the atomic and molecular gas phases of the ISM. The models are adapted from those of Guo et al. using similar methodology as in Fu et al. and are run on halo…
The energy released by Active Galactic Nuclei (AGN) in the form of radiation, winds, or radio plasma jets, is known to impact on the surrounding interstellar medium. The result of these processes, known as AGN (negative) feedback, is…
Recent observations have found extended multi-phase gas in a significant fraction of massive elliptical galaxies. We perform high-resolution three-dimensional hydrodynamical simulations of two idealized elliptical galaxies -- one…
There is no shortage of energy around to solve the overcooling problem of cooling flow clusters. AGNs, as well as gravitational energy are both energetic enough to balance the cooling of cores of clusters. The challenge is to couple this…
The lack of very cool gas at the cores of groups and clusters of galaxies, even where the cooling time is significantly shorter than the Hubble time, has been interpreted as evidence of sources that re-heat the intergalactic medium. Most…
We study whether hierarchical galaxy formation in a concordance $\Lambda$CDM universe can produce enough massive and red galaxies compared to the observations. We implement a semi-analytical model in which the central black holes gain their…
The self-gravitating systems are formed by particles interacting through gravity. They describe structure formation in the universe. As a consequence of the long range interaction of gravity, they are inhomogeneous even at thermal…