相关论文: Constraining black hole feedback in galaxy cluster…
Feedback from active galactic nuclei (AGN) is believed to be the most promising solution to the cooling flow problem in cool-core clusters, though how exactly the jet energy is transformed into heat is a subject of debate. Dissipation of…
High resolution X-ray spectroscopy of the hot gas in galaxy clusters has shown that the gas is not cooling to low temperatures at the predicted rates of hundreds to thousands of solar masses per year. X-ray images have revealed giant…
We propose a scenario in which a large fraction, or even most, of the gas cooling to low temperatures of T<10^4 K in cooling flow clusters, directly gains energy from the central black hole. Most of the cool gas is accelerated to…
We compute 3D gasdynamical models of jet outflows from the central AGN, that carry mass as well as energy to the hot gas in galaxy clusters and groups. These flows have many attractive attributes for solving the cooling flow problem: why…
Feedback driven by jets from active galactic nuclei is believed to be responsible for reducing cooling flows in cool-core galaxy clusters. We use simulations to model feedback from hydrodynamic jets in isolated halos. While the jet…
We present the statistical analysis of X-ray surface brightness and gas density fluctuations in cool cores of ten, nearby and bright galaxy clusters that have deep Chandra observations and show observational indications of radio-mechanical…
Extended filamentary H$\alpha$ emission nebulae are a striking feature of nearby galaxy clusters but the formation mechanism of the filaments, and the processes which shape their morphology remain unclear. We conduct an investigation into…
Heating from active galactic nuclei (AGN) is thought to stabilize cool-core clusters, limiting star formation and cooling flows. We employ radiative magneto-hydrodynamic (MHD) simulations to model light AGN jet feedback with different…
Understanding heating processes in galaxy clusters is essential for predicting the regulation of radiative cooling and star formation, and for clarifying the mechanisms underlying active galactic nucleus (AGN) feedback in cool-core…
Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100~kpc of the Perseus cluster using observations obtained with the Hitomi satellite.…
Supermassive black holes (SMBHs) are thought to provide energy that prevents catastrophic cooling in the centers of massive galaxies and galaxy clusters. However, it remains unclear how this "feedback" process operates. We use…
Jets provide an important channel for kinetic feedback from accreting black holes into their environment, without which models of the formation of large-scale structure in the universe fail to reproduce the observed properties of galaxies.…
We place constraints on the propagation velocity of bulk turbulence within the intracluster medium of three clusters and an elliptical galaxy. Using Reflection Grating Spectrometer measurements of turbulent line broadening, we show that for…
New X-ray observations with XMM-Newton show a lack of spectral evidence for large amounts of cooling and condensing gas in the centers of galaxy clusters believed to harbour strong cooling flows. Here, we explore these diagnostics of the…
Galaxy clusters, the Universe's largest halo structures, are filled with 10-100 million degree X-ray-emitting gas. Their evolution is shaped by energetic processes such as feedback from supermassive black holes (SMBHs) and mergers with…
Cores of relaxed galaxy clusters are often disturbed by AGN. Their Chandra observations revealed a wealth of structures induced by shocks, subsonic gas motions, bubbles of relativistic plasma, etc. In this paper, we determine the nature and…
Whether caused by AGN jets, shocks, or mergers, the most definitive evidence for heating in cluster cores comes from X-ray spectroscopy. Unfortunately such spectra are essentially limited to studying the emission spectrum from the cluster…
Jet feedback from active galactic nuclei (AGN) harboured by brightest cluster galaxies is expected to play a fundamental role in regulating cooling in the intracluster medium (ICM). While observations and theory suggest energy within jet…
Nowhere is black hole feedback seen in sharper relief than in the Perseus cluster of galaxies. Owing to a combination of astrophysical and instrumental challenges, however, it can be difficult to study the black hole accretion that powers…
We study the feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow (CF) galaxies and clusters. We adopt the popular view that the heating is due to an active galactic nucleus (AGN), i.e. a central black hole…