相关论文: Magnetic arms generated by multiple interfering ga…

Recent observations show that the Milky Way's metallicity distribution function (MDF) changes its shape as a function of radius. This new evidence of radial migration within the stellar disc sets additional constraints on Galactic models.…

The majority of astrophysics involves the study of spiral galaxies, and stars and planets within them, but how spiral arms in galaxies form and evolve is still a fundamental problem. Major progress in this field was made primarily in the…

The role of spiral arms in galaxies -- whether they enhance star formation efficiency or primarily act as material gatherers -- remains an open question. Observational studies have yielded ambiguous results, in part due to the choice of…

Isotropic and anisotropic wavelet transforms are used to decompose the images of the spiral galaxy M83 in various tracers to quantify structures in a range of scales from 0.2 to 10 kpc. We used radio polarization observations at {\lambda}6…

High resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred disks present spiral arms nearly…

Radio synchrotron emission is a powerful tool to study the strength and structure of magnetic fields in galaxies. Unpolarized synchrotron emission traces isotropic turbulent fields which are strongest in spiral arms and bars (20-30 \mu G)…

We establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disk galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second one displays a…

We investigate the impact of spiral structure on global star formation using a sample of 2226 nearby bright disk galaxies. Examining the relationship between spiral arms, star formation rate (SFR), and stellar mass, we find that arm…

Spiral arms are observed in numerous protoplanetary discs. These spiral arms can be excited by companions, either on bound or unbound orbits. We simulate a scenario where an unbound perturber, i.e. a flyby, excites spiral arms during a…

We propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the unstable equilibrium points of the rotating bar potential. Thus,…

Spiral density wave theory attempts to describe the spiral pattern in spiral galaxies in terms of a long-lived wave structure with a constant pattern speed in order to avoid the winding dilemma. The pattern is consequently a rigidly…

The generation of spiral arms and the mechanisms controlling their properties within a realistic cosmological framework - the complete understanding is still beyond our grasp. Using a statistically significant sample of Milky Way- and…

Spiral arms are the most characteristic features of disc galaxies, easily distinguishable due to their association with ongoing star formation. However, the role of spiral structure in the chemical evolution of galaxies is unclear. Here we…

In this and in a previous paper (Romero-Gomez et al. 2006) we propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the…

Observations of dwarf galaxies suggest the presence of large-scale magnetic fields. However the size and slow rotation of these galaxies appear insufficient to support a mean-field dynamo action to excite such fields. Here we suggest a new…

Interstellar magnetic fields are strong: up to 25 muG in spiral arms and 40 muG in nuclear regions. In the spiral galaxy NGC 6946 the average magnetic energy density exceeds that of the thermal gas. Magnetic fields control the evolution of…

We describe how a simple class of out of equilibrium, rotating and asymmetrical mass distributions evolve under their self-gravity to produce a quasi-planar spiral structure surrounding a virialized core, qualitatively resembling a spiral…

Spiral structures are important drivers of the secular evolution of disc galaxies, however, the origin of spiral arms and their effects on the development of galaxies remain mysterious. In this work, we present two three-armed spiral…

We consider the possible pattern of the overall spiral structure of the Galaxy, using data on the distribution of neutral (atomic), molecular, and ionized hydrogen, on the base of the hypothesis of the spiral structure being symmetric, i.e.…

We use a high resolution cosmological zoom simulation of a Milky Way-sized halo to study the observable features in velocity and metallicity space associated with the dynamical influence of spiral arms. For the first time, we demonstrate…