相关论文: Formation of cold molecular filaments in cooling f…

The physical relationship between low-excitation gas filaments at ~10^4 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~10^7 K in the centers of many galaxy clusters is not understood. It is unclear whether the…

Mechanical feedback via Active Galactic Nuclei (AGN) jets in the centres of galaxy groups and clusters is a crucial ingredient in current models of galaxy formation and cluster evolution. Jet feedback is believed to regulate gas cooling and…

Cool core clusters of galaxies require strong feedback from their central AGN to offset cooling. We present a study of strong cool core, highly-luminous (most with L_x > 10^(45) erg/s), clusters of galaxies in which the mean central AGN jet…

Using an analytical model and numerical simulations, we show that acoustic waves generated by turbulent motion in intracluster medium effectively heat the central region of a so-called ``cooling flow'' cluster. We assume that the turbulence…

We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone…

We report new ALMA observations of the CO(3-2) line emission from the $2.1\pm0.3\times10^{10}\rm\thinspace M_{\odot}$ molecular gas reservoir in the central galaxy of the Phoenix cluster. The cold molecular gas is fuelling a vigorous…

We present Chandra X-ray Observatory observations of the core of the galaxy cluster PKS 0745-191. Its centre shows X-ray cavities caused by AGN feedback and cold fronts with an associated spiral structure. The cavity energetics imply they…

We analyzed the feedback of AGN jets on cooling flow clusters using three-dimensional AMR hydrodynamic simulations. We studied the interaction of the jet with the intracluster medium and creation of low X-ray emission cavities (Bubbles) in…

It is commonly thought that AGN feedback can break the self-similar scaling relations of galaxies, groups, and clusters. Using high-resolution 3D hydrodynamic simulations, we isolate the impact of AGN feedback on the $L_{\rm x}-T_{\rm x} $…

We present the first observations of emission lines of CN(2-1), HCO$^{+}$(3-2) and C$_{2}$H(3-2) in the Perseus cluster. We observed at two positions: directly at the central galaxy, NGC 1275 and also at a position about 20$''$ to the east…

In many clusters of galaxies there is evidence for cooling flow in the central regions. A possibility is that a fraction of the gas forms cold molecular clouds. We investigate the minimum temperature which can be reached by clouds in…

Recent observations show that the cooling flows in the central regions of galaxy clusters are highly suppressed. Observed AGN-induced cavities/bubbles are a leading candidate for suppressing cooling, usually via some form of mechanical…

We present an analysis of new and archival ALMA observations of molecular gas in twelve central cluster galaxies. We examine emerging trends in molecular filament morphology and gas velocities to understand their origins. Molecular gas…

We present VLT-SINFONI K-band IFU spectroscopy of the central galaxies in the cool core clusters A1664, A2204 and PKS 0745-191, to probe the Pa-alpha and ro-vibrational H2 line emission. In A1664 the two emission-line velocity systems seen…

In recent years evidence has accumulated suggesting that the gas in galaxy clusters is heated by non-gravitational processes. Here we calculate the heating rates required to maintain a physically motived mass flow rate, in a sample of seven…

Recent analysis shows that it is important to explicitly include the gravitational potential of the central brightest central galaxy (BCG) to infer the acceleration due to gravity ($g$) and the free-fall time ($t_{\rm ff} \equiv…

We present a new analysis of very deep Chandra observations of the galaxy cluster Abell 1795. Utilizing nearly 750 ks of net ACIS imaging, we are able to resolve the thermodynamic structure of the Intracluster Medium (ICM) on length scales…

We investigate whether the swirling cold front in the core of the Perseus Cluster of galaxies has affected the outer buoyant bubbles that originated from jets from the Active Galactic Nucleus in the central galaxy NGC1275. The inner bubbles…

We present the results of a combined X-ray and Halpha study of 10 galaxy groups and 17 galaxy clusters using the Chandra X-ray Observatory and the Maryland Magellan Tunable Filter. We find no difference in the morphology or detection…

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…