相关论文: Explaining the reportedly over-massive black holes…
Recent observational studies of ultra-compact dwarf galaxies (UCDs) have discovered massive black holes (MBHs) with masses of more than ${10^6~\rm M_\odot}$, in their central regions. We here consider that these MBHs can be formed through…
The inner Galaxy is the most complex region of the Milky Way, comprising the bulge, inner thin and thick discs, and inner halo; the formation of the bar transferred gas and stars from the disc inward. Accretion of dwarf galaxies also…
The formation of thick stellar disks in spiral galaxies is studied. Simulations of gas-rich young galaxies show formation of internal clumps by gravitational instabilities, clump coalescence into a bulge, and disk thickening by strong…
Massive galaxies at high-z have smaller effective radii than those today, but similar central densities. Their size growth therefore relates primarily to the evolving abundance of low-density material. Various models have been proposed to…
Located in the Perseus cluster, NGC 1271 is an early-type galaxy with a small effective radius of 2.2 kpc and a large stellar velocity dispersion of 276 km/s for its K-band luminosity of 8.9x10^{10} L_sun. We present a mass measurement for…
We explore the potential cumulative energy production of stellar mass black holes in early galaxies. Stellar mass black holes may accrete substantially from the higher density interstellar media of primordial galaxies, and their energy…
Early-type dwarf galaxies constitute a prevalent population in the central regions of rich groups and clusters in the local Universe. These low-luminosity and low-mass stellar systems play a fundamental role in the assembly of the luminous…
We explore the elemental abundance features of metal-rich disk stars, highlighting the comparisons made with those of the recently revealed Galactic bulge stars. A similarity between two of the comparisons leads to a new theoretical picture…
Any realistic theory of galaxy formation must be set in the context of a model for the formation of structure in the universe. We describe a powerful approach -- semi-analytic modelling -- that combines a set of simple rules describing the…
Radiation pressure-dominated accretion disks are predicted to exhibit strong density inhomogeneities on scales much smaller than the disk scale height, due to the nonlinear development of photon bubble instability. Radiation would escape…
We present near-infrared (NIR) surface photometry of a sample of 14 early-type spirals with observed rotation curves. In this first paper, we report the results of two-dimensional parametric and non-parametric decompositions to separate the…
The study of intermediate-mass black holes (IMBHs) is a young and promising field of research. Formed by runaway collisions of massive stars in young and dense stellar clusters, intermediate-mass black holes could still be present in the…
Super-massive black holes, with masses larger than a million times that of the Sun, appear to inhabit the centers of all massive galaxies. Cosmologically-motivated theories of galaxy formation need feedback from these super-massive black…
We analyze the dependence of the stellar disc flatness on the galaxy morphological type using 2D decomposition of galaxies from the reliable subsample of the Edge-on Galaxies in SDSS (EGIS) catalogue. Combining these data with the retrieved…
We present new upper limits for black hole masses in extremely late type spiral galaxies. We confirm that this class of galaxies has black holes with masses less than 10^6 Msolar, if any. We also derive new upper limits for nuclear star…
M32 is the prototype for the relatively rare class of galaxies referred to as `compact ellipticals'. It has been suggested that M32 may be a tidally disturbed r^(1/4) elliptical galaxy, or the remnant bulge of a disk-stripped early-type…
Lenticular galaxies (S0s) represent the majority of early-type galaxies in the local Universe, but their formation channels are still poorly understood. While galaxy mergers are obvious pathways to suppress star formation and increase bulge…
From two very simple axioms: (1) that AGN activity traces spheroid formation, and (2) that the cosmic star-formation history is dominated by spheroid formation at high redshift, we derive simple expressions for the star-formation histories…
Observations of (B-V) colour distributions towards the galactic poles are compared with those obtained from synthetic colour-magnitude diagrams to determine the major constituents in the disc and spheroid. The disc is described with four…
We present first results from an on-going survey of the stellar populations of the bulges and inner disks of spirals at various points along the Hubble sequence. In particular, we are investigating the hypotheses that bulges of early-type…