The Dynamics of Heavy Gaseous Disks

Laughlin, Gregory; Корчагин, В. И.; Adams, Fred C.

doi:10.1086/306117

Cited by 76 publications

(93 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…spiral activity can be easily recognized at t ≈ 1.5t0, t ≈ 4t0 and t ≈ 6t0. A similar cyclic behaviour, with a modulation of the amplitude of the dominant m = 2 mode, has been found in previous simulations of self-gravitating discs (Sellwood & Carlberg 1984;Laughlin & Bodenheimer 1994;Laughlin et al 1998). Laughlin et al (1998) have attributed this behaviour to the effect of non-linear coupling between different modes.…”

Section: The M Disc = 1m⋆ Casesupporting

confidence: 84%

“…In particular, here we describe the results of two new simulations, in which the disc mass is of the same order of the central object mass, namely M disc = 0.5M⋆ and M disc = 1M⋆. Given the specific region of the parameter space that we explore, our simulations have two previous analogues: the N -body simulations by Sellwood & Carlberg (1984), who mimicked the cooling of the stellar component of a galaxy disc through continuous accretion of stars, and a series of simulations by Laughlin et al (Laughlin & Bodenheimer 1994;Laughlin et al 1997Laughlin et al , 1998, who simulated massive gaseous disc, adopting simple equations of state (mostly isothermal) without any spe-cific cooling. The main difference between the latter simulations and those presented here lies in the way we handle the disc thermodynamics.…”

Section: Discussionmentioning

confidence: 99%

“…If we interpret this in the same way as (Laughlin et al 1998), non-linear coupling between the different modes results in episodes when m = 2 modes heat the outer disc and make it more stable, followed be episodes when cooling dominates, and the disc is driven back towards a period of instability. Figure 12.…”

Section: Secular Evolutionmentioning

confidence: 90%

See 2 more Smart Citations

Testing the locality of transport in self-gravitating accretion discs

Lodato

Rice

2004

AIP Conference Proceedings

View full text Add to dashboard Cite

In this paper, we extend our previous analysis of the transport properties induced by gravitational instabilities in cooling, gaseous accretion discs to the case where the disc mass is comparable to the central object. In order to do so, we have performed global, three-dimensional smoothed particle hydrodynamics simulations of massive discs. These new simulations show a much more complex temporal evolution with respect to the less massive case. Whereas in the low disc mass case a self-regulated, marginally stable state (characterized by an approximately constant radial profile of the stability parameter Q) is easily established, in the high disc mass case we observe the development of an initial transient and subsequent settling down in a self-regulated state in some simulations, or a series or recurrent spiral episodes, with low azimuthal wave number m, in others. Accretion in this last case can therefore be a highly variable process. On the other hand, we find that the secular evolution of the disc is relatively slow. In fact, the time-average of the stress induced by selfgravity results in accretion time-scales much longer than the dynamical timescale, in contrast with previous isothermal simulations of massive accretion discs. We have also compared the resulting stress tensor with the expectations based on a local theory of transport, finding no significant evidence for global wave energy transport.

show abstract

Section: The M Disc = 1m⋆ Casesupporting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Testing the locality of transport in self-gravitating accretion discs

Lodato

Rice

2004

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…In the disc region 10 −2 AU x 1AU Toomre's Q value is Q ∼ 2 − 3. As pointed out in previous studies, the disc becomes unstable against non-axisymmetric perturbations when Q ∼ 1.5 and the spiral arms develop (Laughlin, Korchagin & Adams 1998). The spiral arms invoke an angular momentum transfer.…”

Section: Rotationally Supported Disc Around Protostarsupporting

confidence: 56%

Effects of Ohmic and ambipolar diffusion on formation and evolution of first cores, protostars, and circumstellar discs

Tsukamoto

Iwasaki

Okuzumi

et al. 2015

Mon. Not. R. Astron. Soc.

125

116

View full text Add to dashboard Cite

We investigate the formation and evolution of a first core, protostar, and circumstellar disc with a three-dimensional non-ideal (including both Ohmic and ambipolar diffusion) radiation magnetohydrodynamics simulation. We found that the magnetic flux is largely removed by magnetic diffusion in the first core phase and that the plasma β of the centre of the first core becomes large, β > 10 4 . Thus, proper treatment of first core phase is crucial in investigating the formation of protostar and disc. On the other hand, in an ideal simulation, β ∼ 10 at the centre of the first core. The simulations with magnetic diffusion show that the circumstellar disc forms at almost the same time of protostar formation even with a relatively strong initial magnetic field (the value for the initial mass-to-flux ratio of the cloud core relative to the critical value is µ = 4). The disc has a radius of r ∼ 1 AU at the protostar formation epoch. We confirm that the disc is rotationally supported. We also show that the disc is massive (Q ∼ 1) and that gravitational instability may play an important role in the subsequent disc evolution.

show abstract

“…Thus, amplitude is naturally spread from lower order to higher order as the available m-values increase. Indeed, even if the disk is dominated by a few low-order modes at the time of outburst, this power spreads to all m-values in the nonlinear regime (for example Laughlin et al 1997Laughlin et al , 1998Laughlin & Rozyczka 1996).…”

Section: Non-axisymmetric Structurementioning

confidence: 99%

Convergence Studies of Mass Transport in Disks With Gravitational Instabilities. I. The Constant Cooling Time Case

Michael

Steiman-Cameron

Durisen

et al. 2012

ApJ

View full text Add to dashboard Cite

We conduct a convergence study of a protostellar disk, subject to a constant global cooling time and susceptible to gravitational instabilities (GIs), at a time when heating and cooling are roughly balanced. Our goal is to determine the gravitational torques produced by GIs, the level to which transport can be represented by a simple α-disk formulation, and to examine fragmentation criteria. Four simulations are conducted, identical except for the number of azimuthal computational grid points used. A Fourier decomposition of non-axisymmetric density structures in cos(mφ), sin(mφ) is performed to evaluate the amplitudes A m of these structures. The A m , gravitational torques, and the effective Shakura & Sunyaev α arising from gravitational stresses are determined for each resolution. We find nonzero A m for all m-values and that A m summed over all m is essentially independent of resolution. Because the number of measurable m-values is limited to half the number of azimuthal grid points, higher-resolution simulations have a larger fraction of their total amplitude in higher-order structures. These structures act more locally than lower-order structures. Therefore, as the resolution increases the total gravitational stress decreases as well, leading higher-resolution simulations to experience weaker average gravitational torques than lower-resolution simulations. The effective α also depends upon the magnitude of the stresses, thus α eff also decreases with increasing resolution. Our converged α eff is consistent with predictions from an analytic local theory for thin disks by Gammie, but only over many dynamic times when averaged over a substantial volume of the disk.

show abstract

The Dynamics of Heavy Gaseous Disks

Cited by 76 publications

References 27 publications

Testing the locality of transport in self-gravitating accretion discs

Testing the locality of transport in self-gravitating accretion discs

Effects of Ohmic and ambipolar diffusion on formation and evolution of first cores, protostars, and circumstellar discs

Convergence Studies of Mass Transport in Disks With Gravitational Instabilities. I. The Constant Cooling Time Case

Contact Info

Product

Resources

About