English
Related papers

Related papers: Shear-gravity transition determines the steep velo…

200 papers

Kinetic energy stored in ISM bulk/turbulent motions is a crucial ingredient to properly describe most properties of observed galaxies. By using Monte Carlo simulations, we investigate how this energy is injected by supernovae and dissipated…

Astrophysics · Physics 2009-11-07 Massimo Ricotti , Andrea Ferrara

The relation of the shear viscosity coefficient to the recently introduced transport rate is derived within relativistic kinetic theory. We calculate the shear viscosity over entropy ratio \eta/s for a gluon gas, which involves elastic gg->…

Nuclear Theory · Physics 2008-11-26 Zhe Xu , Carsten Greiner

We perform numerical simulations to examine particle diffusion at steady shear in a model granular material in two dimensions at the jamming density and zero temperature. We confirm findings by others that the diffusion constant depends on…

Soft Condensed Matter · Physics 2015-05-14 Peter Olsson

We study the relationship between the scale-height of the molecular gas disc and the turbulent velocity dispersion of the molecular interstellar medium within a simulation of a Milky Way-like galaxy in the moving-mesh code Arepo. We find…

Astrophysics of Galaxies · Physics 2022-07-20 Sarah M. R. Jeffreson , Jiayi Sun , Christine D. Wilson

Using a large sample of 9617 molecular clouds (MCs) from the Milky Way Imaging Scroll Painting survey, we mainly measure one-dimensional cloud-to-cloud velocity dispersions across a 450 deg$^{2}$ segment of the Local arm in the Galactic…

Astrophysics of Galaxies · Physics 2025-06-17 Lixia Yuan , Ji Yang

We investigate the relationship between the velocity dispersion of the gas and the SN rate and feedback efficiency in the ISM. We explore the constancy of the velocity dispersion profiles in the outer parts of galactic disks at~6-8 km s^-1,…

Astrophysics · Physics 2009-11-11 Sami Dib , Eric Bell , Andreas Burkert

The molecular component of the Galaxy is comprised of turbulent, magnetized clouds, many of which are self-gravitating and form stars. To understand how these clouds' evolution may depend on their level of turbulence, mean magnetization,…

Astrophysics · Physics 2009-10-31 Eve C. Ostriker , Charles F. Gammie , James M. Stone

It has long been suggested that shocks might play an important role in altering the form of the interstellar medium (ISM). Shocks enhance gas density and sufficiently dense regions may become self gravitating. Potential star forming clouds…

Astrophysics · Physics 2015-05-13 S. V. Anathpindika

We do shear-driven simulations of a simple model of non-Brownian particles in two dimensions. By examining the velocity distribution at different densities and shear rates we find strong evidence for the existence of two different…

Soft Condensed Matter · Physics 2023-06-14 Peter Olsson

Dense suspensions often exhibit a dramatic response to large external deformation. The recent body of work has related this behavior to transition from an unconstrained lubricated to a constrained frictional state. Here, we use numerical…

Soft Condensed Matter · Physics 2023-05-24 Abhinendra Singh , Kuniyasu Saitoh

We have used integral field spectroscopy of a sample of six nearby (z~0.01-0.04) high star-formation rate (SFR~10-40 solar masses per year) galaxies to investigate the relationship between local velocity dispersion and star formation rate…

Astrophysics of Galaxies · Physics 2016-03-23 Mathew Varidel , Michael Pracy , Scott Croom , Matt Owers , Elaine Sadler

The stellar velocity dispersion, $\sigma$, is a quantity of crucial importance for spiral galaxies, where it enters fundamental dynamical processes such as gravitational instability and disc heating. Here we analyse a sample of 34 nearby…

Astrophysics of Galaxies · Physics 2019-09-25 Keoikantse Moses Mogotsi , Alessandro B. Romeo

Stars form in the densest regions of molecular clouds, however, there is no universal understanding of the factors that regulate cloud dynamics and their influence on the gas-to-stars conversion. This study considers the impact of Galactic…

Astrophysics of Galaxies · Physics 2024-07-01 Raffaele Rani , Jia-Lun Li , Toby J. T. Moore , David J. Eden , Andrew J. Rigby , Geumsook Park , Yueh-Ning Lee

The shear viscosity in the dilute regime of a model for confined granular matter is studied by simulations and kinetic theory. The model consists on projecting into two dimensions the motion of vibrofluidized granular matter in shallow…

Statistical Mechanics · Physics 2015-06-22 Rodrigo Soto , Dino Risso , Ricardo Brito

The interaction of turbulence, magnetic fields, self-gravity, and stellar feedback within molecular clouds is crucial for understanding star formation. We study the effects of self-gravity and outflow feedback on the properties of the…

Astrophysics of Galaxies · Physics 2022-04-25 Yue Hu , Christoph Federrath , Siyao Xu , Sajay Sunny Mathew

We argue that impact velocities between dust grains with sizes less than $\sim 0.1$ $\mu m$ in molecular cloud cores are dominated by drift arising from ambipolar diffusion. This effect is due to the size dependence of the dust coupling to…

Astrophysics of Galaxies · Physics 2020-09-30 Kedron Silsbee , Alexei Ivlev , Paola Caselli , Olli Sipila , Bo Zhao

The stellar velocity dispersion as a function of the galactocentric radius of an early-type galaxy can generally be well approximated by a power law $\sigma \propto r^{\beta}$. However, some observed dispersion profiles show a deviation…

Astrophysics of Galaxies · Physics 2015-06-18 Anna T. P. Schauer , Rhea-Silvia Remus , Andreas Burkert , Peter H. Johansson

Complex mixing and magnetic field generation occurs within stellar interiors particularly where there is a strong shear flow. To obtain a comprehensive understanding of these processes, it is necessary to study the complex dynamics of shear…

Solar and Stellar Astrophysics · Physics 2018-10-17 V. Witzke , L. J. Silvers , B. Favier

Diffusivity is a key quantity in describing velocity fluctuations in granular materials. These fluctuations are the basis of many thermodynamic and hydrodynamic models which aim to provide a statistical description of granular systems. We…

Soft Condensed Matter · Physics 2009-11-10 Brian Utter , R. P. Behringer

Velocity dispersion ($\sigma$) is a key driver for galaxy structure and evolution. We here present a comprehensive semi-empirical approach to compute $\sigma$ via detailed Jeans modelling assuming both a constant and scale-dependent…

Astrophysics of Galaxies · Physics 2022-01-05 Christopher Marsden , Francesco Shankar , Mariangela Bernardi , Ravi Sheth , Hao Fu , Andrea Lapi