相关论文: Hidden Bars and Boxy Bulges
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…
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…
Boxy/peanut bulges in disc galaxies have been associated to stellar bars. We analyse their properties in a large sample of $N$-body simulations, using different methods to measure their strength, shape and possible asymmetry, and then…
We have observed 60 edge-on galaxies in the NIR in order to study the stellar distribution in galaxies with box/peanut-shaped bulges. The much smaller amount of dust extinction at these wavelengths allows us to identify in almost all target…
Boxy/peanut bulges in disk galaxies have been associated to stellar bars. In this talk, we discuss the different properties of such bulges and their relation with the corresponding bar, using a very large sample of a few hundred numerical…
It has been suggested that the peanut-shaped bulges seen in some edge-on disk galaxies are due to the presence of a central bar. Although bars cannot be detected photometrically in edge-on galaxies, we show that barred potentials produce a…
We present a systematic observational study of the relationship between bars and boxy/peanut-shaped (B/PS) bulges. We first review and discuss proposed mechanisms for their formation, focussing on accretion and bar-buckling scenarios. Using…
Inspecting all 1224 edge-on disk galaxies larger than 2' in the RC3 on DSS images we have found several galaxies with extraordinary bulges meeting two criteria: They are box shaped and large in respect to the diameters of their galaxies.…
Objects designated as bulges in disc galaxies do not form a homogeneous class. I distinguish three types. The classical bulges, whose properties are similar to those of ellipticals and which form by collapse or merging. Boxy and peanut…
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 present a near-infrared K_n-band photometric study of edge-on galaxies with a box/peanut-shaped `bulge'. The morphology of the galaxies is analysed using unsharp masking and fits to the vertical surface brightness profiles, and the…
Boxy/peanut and X-shaped (BP/X) bulges are prominent features in edge-on disk galaxies and are believed to be vertically thickened bars. Despite their relevance in bar evolution, a statistically robust census of these structures in large…
Barred galaxies have interesting morphological features whose presence and properties set constraints on galactic evolution. Here we examine barlenses, i.e. lens-like components whose extent along the bar major axis is shorter than that of…
We review the observed morphological, photometric, and kinematic properties of boxy/peanut (B/P) shape bulges. Nearly half of the bulges in the nearby edge-on galaxies have these characteristics, which fraction is similar to the observed…
Boxy edge-on profiles can be accounted for not only in models of barred galaxies, but also in models of normal (non-barred) galaxies. Thus, the presence of a bar is not a sine qua non condition for the appearance of this feature, as often…
Present in over 45% of local spirals, boxy and peanut-shaped bulges are generally interpreted as edge-on bars and may represent a key phase in the evolution of bulges. Aiming to test such claims, the kinematic properties of self-consistent…
The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate…
We present a classification for bulges of a complete sample of ~1350 edge-on disk galaxies derived from the RC3 (Third Reference Catalogue of Bright Galaxies, de Vaucouleurs et al. 1991). A visual classification of the bulges using the…
We show that direct detection and measurement of the vertically thickened parts of bars (so-called "boxy" or "peanut-shaped" bulges) is possible not only for edge-on galaxies but also for galaxies with moderate inclinations (i < 70 deg),…
The Galactic bulge is now considered to be the inner three-dimensional part of the Milky Way's bar. It has a peanut shape and is characterized by cylindrical rotation. In N-body simulations, box/peanut bulges arise from disks through bar…