相关论文: Active galactic nuclei and the minor merger hypoth…

Seyfert nuclei are typical active galactic nuclei (AGNs) in the local universe, which are thought to be powered by gas accretion onto a supermassive black hole (SMBH). The dynamical effect exerted either by non-axisymmetric gravitational…

The large scale (~ 100 kpc) environments of Seyfert galaxies are not significantly different from those of non-Seyfert galaxies. In the context of the interaction model of the formation of active galactic nuclei (AGN), it has been proposed…

Mergers between gas--rich disks and less--massive dwarf galaxies are studied using numerical simulation. As the orbit of a satellite decays through dynamical friction, the primary disk develops large-amplitude spirals in response to its…

We analyse the phase-space structure of simulated thick discs that are the result of a significant merger between a disc galaxy and a satellite. Our main goal is to establish what would be the characteristic imprints of a merger origin for…

Nuclear disks and rings are frequent galaxy substructures, for a wide range of morphological types (from S0 to Sc). We have investigated the possible minor-merger origin of inner disks and rings in spiral galaxies through collisionless…

Based on SDSS data, we consider the fraction of active galactic nuclei among polar-ring galaxies. We have found evidence for an excess of Seyfert galaxies and LINERs among polar-ring galaxies compared to ordinary objects. The observed…

We use the difference (delta) between the position angles of the nuclear radio emission and the host galaxy major axis to investigate the distribution of the angle (beta) between the axes of the nuclear accretion disk and the host galaxy…

The decay of globular clusters to the center of their mother galaxy corresponds to carrying a quantity of mass sufficient to sustain the gravitational activity of a small pre-existing nucleus and to accrete it in a significant way. This is…

The orientation of radio jets relative to their host galaxies offers an interesting avenue for probing the connection between active galactic nuclei (AGN) and their surroundings. Several studies have also investigated the orientation of…

Galactic nuclei should contain a cluster of stars and compact objects in the vicinity of the central supermassive black hole due to stellar evolution, minor mergers and gravitational dynamical friction. By analogy with protoplanetary…

We present simulations of the formation of thick disks via the accretion of two-component satellites onto a pre-existing thin disk. Our goal is to establish the detailed characteristics of the thick disks obtained in this way, as well as…

Galaxy major mergers are a potential mechanism for triggering active galactic nuclei (AGN) activity, but their role remains debated, particularly beyond the local Universe. We aim to shed light on the merger-AGN connection at $z=0.5$-$2$,…

A significant fraction of nearby galaxies show evidence of weak nuclear activity unrelated to normal stellar processes. Recent high-resolution, multiwavelength observations indicate that the bulk of this activity derives from black hole…

We perform fully self-consistent stellar dynamical simulations of the accretion of a companion ("satellite") galaxy by a large disk galaxy to investigate the interaction between the disk, halo, and satellite components of the system during…

The link between nuclear activity and the host galaxy remains elusive. It seems now clear that the galactic environment is not the key, and that there is no significant apparent difference in terms of the presence of bars/spirals between…

We suggest that most nearby active galactic nuclei are fed by a series of small--scale, randomly--oriented accretion events. Outside a certain radius these events promote rapid star formation, while within it they fuel the supermassive…

Mergers of neutron stars with black holes have been suggested as candidates for short gamma-ray bursts. They have also been studied for their potential as gravitational wave sources observable with ground-based detectors. For these…

Using recent high-resolution radio observations of a large sample of Seyfert galaxies (Roy et al. 1994), we analyze the relations between the compact radio core emission and several nuclear and host galaxy properties. Seyfert nuclei hosted…

A large fraction of bulgeless disk galaxies contain young compact stellar systems at their centers, in spite of the local gravitational stability of these disks. We evaluate two contrasting hypotheses for the origin of the nuclear star…

We discuss the structure of a central stellar cluster whose dynamics is influenced by gravitation of a supermassive black hole and by the dissipative interaction of orbiting stars with an accretion disc. We also take the effect of disc…