相关论文: How do different spiral arm models impact the ISM …
Spiral arms are distinctive features of many circumstellar disks, observed in scattered light, which traces the disk surface, millimeter dust emission, which probes the disk midplane, as well as molecular emission. The two leading…
Interfering two- and three-arm spiral patterns have previously been inferred to exist in many galaxies and also in numerical simulations, and invoked to explain important dynamical properties, such as lack of symmetry, kinks in spiral arms,…
The Milky Way spiral arms are well established from star counts as well as from the locus of molecular clouds and other young objects, however, they have only recently started to be observed from a kinematics point of view. Using the…
We examine whether various characteristics of planet-driven spiral arms can be used to constrain the masses of unseen planets and their positions within their disks. By carrying out two-dimensional hydrodynamic simulations varying planet…
I review recent results derived from numerical simulations of the turbulent interstellar medium (ISM), in particular concerning the nature and formation of turbulent clouds, methods for comparing the structure in simulations and…
We investigate dynamical states of grand-design spiral arms in three local galaxies: M51, NGC3627 and NGC628. Based on linear perturbation analysis considering multiple components in the galaxies, we compute instability parameters of the…
We present a 2-dimensional chemical evolution code applied to a Milky Way type galaxy, incorporating the role of spiral arms in shaping azimuthal abundance variations, and confront the predicted behaviour with recent observations taken with…
Spiral arms greatly affect gas flows and star formation in disk galaxies. We use local three-dimensional simulations of the vertically-stratified, self-gravitating, differentially-rotating, interstellar medium (ISM) subject to a stellar…
We study the effect of spiral arm passages on the evolution of star clusters on planar and circular orbits around the centres of galaxies. Individual passages with different relative velocity (V_drift) and arm width are studied using N-body…
Faraday rotation measurements of polarized extragalactic sources probe the Galactic magnetized, ionized interstellar medium. Rotation measures of these sources behind the inner Galactic plane are used to explore characteristics of the…
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…
Direct imaging observations have revealed spiral structures in protoplanetary disks. Previous studies have suggested that planet-induced spiral arms cannot explain some of these spiral patterns, due to the large pitch angle and high…
Simulations from the scales of isolated galaxies to clouds have been instrumental in informing us about molecular cloud formation and evolution. Simulations are able to investigate the roles of gravity, feedback, turbulence, heating and…
Studying the nature of spiral arms is essential for understanding the formation of the intricate disc structure of the Milky Way. The European Space Agency's Gaia mission has provided revolutionary observational data that have uncovered…
We have measured the positions of large numbers of H II regions in four nearly face-on, late-type, spiral galaxies: NGC 628 (M 74), NGC 1232, NGC 3184 and NGC 5194 (M 51). Fitting log-periodic spiral models to segments of each arm yields…
We study the effects of dusty spiral arms on the photometric properties of disk galaxies using a series of 2D radiative transfer models, approximating the arms with axially symmetrical rings. We find that dusty arms, as well as dusty disks,…
We propose a new, more realistic, description of the perturbed gravitational potential of spiral galaxies, with spiral arms having Gaussian-shaped groove profiles. We investigate the stable stellar orbits in galactic disks, using the new…
We present hydrodynamical models of the grand design spiral M51 (NGC 5194), and its interaction with its companion NGC 5195. Despite the simplicity of our models, our simulations capture the present day spiral structure of M51 remarkably…
By resimulating a region of a global disc simulation at higher resolution, we resolve and study the properties of molecular clouds with a range of masses from a few 100's M$_{\odot}$ to $10^6$ M$_{\odot}$. The purpose of our paper is…
We study the impact of possible spiral-arm distributions of Galactic cosmic-ray sources on the flux of various cosmic-ray nuclei throughout our Galaxy. We investigate model cosmic-ray spectra at the nominal position of the sun and at…