相关论文: Bulges or Bars from Secular Evolution?

The observations of bulge/disk segregation in the Universe are reviewed with a focus on whether the observed segregation in clusters is local or global, and whether there is bulge-disk segregation on large-scales. The high concentration of…

A historical review of our understanding of bulges is first presented, highlighting similarities and differences between bulges and ellipticals. Then, some topics of current interest are reviewed, bypassing stellar population questions and…

We present our recent results on the properties of the outskirts of disk galaxies. In particular, we focus on spiral galaxies with stellar disk truncations in their radial surface brightness profiles. Using SDSS, UDF and GOODS data we show…

Bars have a complex three-dimensional shape. In particular their inner part is vertically much thicker than the parts further out. Viewed edge-on, the thick part of the bar is what is commonly known as a boxy-, peanut- or X- bulge and…

We investigate the effects of halo kinematics on the dynamics of stellar discs by simulating the evolution of isolated disc-halo systems from equilibrium initial conditions. Our main results come from four simulations where the initial disc…

Traditionally, secular evolution is defined as evolution of systems where the internal growth of structure and instabilities dominates the growth via external drivers (e.g. accretion/mergers). Most study has focused on 'isolated' galaxies,…

We use numerical simulations of isolated galaxies to study the effects of stellar feedback on the formation and evolution of giant star-forming gas 'clumps' in high-redshift, gas-rich galaxies. Such galactic disks are unstable to the…

Satellite accretion events have been invoked for mimicking the internal secular evolutionary processes of bulge growth. However, N-body simulations of satellite accretions have paid little attention to the evolution of bulge photometric…

In this paper, we use the Galaxy Zoo 2 dataset to study the behavior of bars in disk galaxies as a function of specific star formation rate (SSFR), and bulge prominence. Our sample consists of 13,295 disk galaxies, with an overall (strong)…

We investigate the connection between the vertical structure of stellar discs and the formation of bars using high-resolution simulations of galaxies in isolation and in the cosmological context. In particular, we simulate a suite of…

It has been suggested that the peanut-shaped bulges seen in some edge-on disk galaxies are produced when bars in these galaxies buckle. This paper reviews the modelling which seeks to show how bars buckle, and I present a very simple new…

The last few years witnessed a change of perspective in the context of galaxy formation and evolution. The major role played by bars in the history of these fundamental building blocks of our universe was finally realized. However, and…

The internal evolution of disk galaxies like the Milky Way are driven by non-axisymmetries (bars) and the implied angular momentum transfer of the matter; baryons are essentially driven inwards to build a more concentrated disk. This mass…

The Milky Way as well as a majority of external galaxies possess a thick disc. However, the dynamical role of the (geometrically) thick disc on the bar formation and evolution is not fully understood. Here, we investigate the effect of…

We present results of numerical N-body simulations of a galactic stellar disk embedded into a spherical dark halo. The non-linear dynamics of bending instabilities developing in the disk is studied. The bending modes, axisymmetric and not,…

Lenticular galaxies are generally thought to have descended from spirals via morphological transformation, although recent numerical simulations have shown that minor or even major merger can also lead to an S0-like remnant. These…

We demonstrate that in N-body simulations of isolated disc galaxies there is numerical vertical heating which slowly increases the vertical velocity dispersion and the disc thickness. Even for models with over a million particles in a disc,…

Prompted by work on the buckling instability in barred spiral galaxies, much effort has been devoted lately to the study of boxy/peanut-shaped (B/PS) bulges. Here, we present new bar diagnostics for edge-on spiral galaxies based on periodic…

We investigate possible environmental and morphological trends in the $z\sim0$ bar fraction using two carefully selected samples representative of a low-density environment (the isolated galaxies from the AMIGA sample) and of a dense…

Near infrared images from the COBE satellite presented the first clear evidence that our Milky Way galaxy contains a boxy shaped bulge. Recent years have witnessed a gradual paradigm shift in the formation and evolution of the Galactic…