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Related papers: Spiral waves in accretion discs - observations

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We present ALMA observations of CO $J = 2-1$ and CS $J = 5-4$ emission from the disk around TW~Hydrae. Both molecules trace a predominantly Keplerian velocity structure, although a slowing of the rotation velocity is detected at the outer…

We present spectra of accretion discs around white-dwarfs calculated with an improved and updated version of the Shaviv & Wehrse (1991) model. The new version includes line opacities and convective energy transport and can be used to…

Astrophysics · Physics 2009-06-23 Irit Idan , Jean-Pierre Lasota , Jean-Marie Hameury , Giora Shaviv

HD100546 represents a particularly interesting target to study dynamical planet-disk interactions as various features have been observed in both the dust and gas that provide direct and indirect evidence for ongoing planet formation. In…

In recent years, several protoplanetary discs have been observed to exhibit spirals, both in scattered light and (sub)millimetre continuum data. The HD 100453 binary star system hosts such a disc around its primary. Previous work has argued…

The results of numerical simulations of a gaseous disk in the potential of a stellar spiral density wave are presented. The conditions under which straightened spiral arm segments (rows) form in the gas component are studied. These features…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 S. A. Khoperskov , A. V. Khoperskov , M. A. Eremin , M. A. Butenko

We present a numerical scheme for the evolution of an accretion disc through a dwarf nova outburst. We introduce a time-varying artificial viscosity into an existing smoothed particle hydrodynamics code optimised for two and…

Astrophysics · Physics 2009-10-31 Michael Truss , James Murray , Graham Wynn , Richard Edgar

We have developed a spectrum synthesis method for modeling the UV emission from the accretion disk from cataclysmic variables (CVs). The disk is separated into concentric rings, with an internal structure from the Wade & Hubeny…

Solar and Stellar Astrophysics · Physics 2015-05-28 Raul E. Puebla , Marcos P. Diaz , D. John Hillier , Ivan Hubeny

We present K'(2.1 micron) observations of four nearby flocculent spirals, which clearly show low-level spiral structure and suggest that kiloparsec-scale spiral structure is more prevalent in flocculent spirals than previously supposed. In…

Astrophysics · Physics 2009-10-28 Michele D. Thornley

Many accretion discs have been found to be distorted: either warped due a misalignment in the system, or non-circular as a result of orbital eccentricity or tidal deformation by a binary companion. Warped, eccentric, and tidally distorted…

Solar and Stellar Astrophysics · Physics 2024-09-19 Loren E. Held , Gordon I. Ogilvie

Doppler tomography can provide a powerful means of determining black hole spin when our view to the central regions are revealed and obscured by optically thick orbiting material, and can provide an independent estimate that does not suffer…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Matthew Middleton , Adam Ingram

Close to a black hole, the density of the sub-Keplerian accreting matter becomes higher compared to a spherical flow due to the presence of a centrifugal barrier independent of whether or not a standing shock actually forms. This hot dense…

Astrophysics · Physics 2009-10-30 Sandip K. Chakrabarti

The spiral waves detected in the protostellar disc surrounding Elias 2-27 have been suggested as evidence of the disc being gravitationally unstable. However, previous work has shown that a massive, stable disc undergoing an encounter with…

Solar and Stellar Astrophysics · Physics 2018-06-13 Duncan H. Forgan , John D. Ilee , Farzana Meru

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…

Solar and Stellar Astrophysics · Physics 2015-11-11 Zhaohuan Zhu , Ruobing Dong , James M. Stone , Roman R. Rafikov

We investigate both analytically and numerically the motion of massless particles orbiting primary star in a close circular binary system with particular focus on the gas drag effects. These are the first calculations with particles ranging…

Astrophysics · Physics 2008-11-26 P. Ciecielag , S. Ida , A. Gawryszczak , A. Burkert

The young star Elias 2-27 has recently been observed to posses a massive circumstellar disc with two prominent large-scale spiral arms. In this Letter we perform three-dimensional Smoothed Particle Hydrodynamics simulations, radiative…

Earth and Planetary Astrophysics · Physics 2017-04-26 Farzana Meru , Attila Juhasz , John D. Ilee , Cathie J. Clarke , Giovanni P. Rosotti , Richard A. Booth

Gaia data have revealed vertically asymmetric phase-space structures in the Milky Way (MW) disc, such as phase spirals, indicating vertical oscillations. These oscillations exhibit two distinct modes: the bending mode and the breathing…

Astrophysics of Galaxies · Physics 2025-08-14 Tetsuro Asano , Michiko S. Fujii , Junichi Baba , Simon Portegies Zwart , Jeroen Bédorf

Diskoseismology, the theoretical study of small adiabatic hydrodynamical global perturbations of geometrically thin, optically thick accretion disks around black holes (and other compact objects), is a potentially powerful probe of the…

Astrophysics · Physics 2009-11-16 Manuel Ortega-Rodriguez , Robert V. Wagoner

We use a simple, self-consistent, self-gravitating semi-analytic disc model to conduct an examination of the parameter space in which self-gravitating discs may exist. We then use Monte-Carlo radiative transfer to generate synthetic ALMA…

Earth and Planetary Astrophysics · Physics 2016-02-17 Cassandra Hall , Duncan Forgan , Ken Rice , Tim J. Harries , Pamela D. Klaassen , Beth Biller

Cataclysmic Variables (CVs) are a distinct class of X-ray binaries transferring mass from a donor star to a compact star accretor, a white dwarf. They constitute a laboratory for accretion physics, mechanisms and disk theory together with…

High Energy Astrophysical Phenomena · Physics 2011-12-19 S. Balman

Bipolar outflows are present in many disk-accreting astrophysical systems. In disk-accreting cataclysmic variables (CVs), these outflows are responsible for most of the strong features in the ultraviolet spectra of these systems. However,…

Astrophysics · Physics 2009-11-07 Knox S. Long , Christian Knigge