Angular momentum transport in accretion disks: a hydrodynamical perspective

Fromang, Sébastien; Lesur, Geoffroy

doi:10.1051/eas/1982035

Cited by 25 publications

(20 citation statements)

References 99 publications

(119 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hydrodynamic angular momentum transfer mechanisms generally rely on the onset and sustenance of turbulence, which is closely related to the hydrodynamic stability of the disk [see recent reviews ( 14 , 15 )]. When ignoring thermodynamics, the stability of a disk is described by the well-known Rayleigh criterion ( 16 ), which states that a rotating, inviscid system is linearly stable to axisymmetric perturbations as long as j increases radially outward (∂ j / ∂R > 0) ( Fig.…”

Section: Theorymentioning

confidence: 99%

“…Three purely hydrodynamic instabilities have recently been considered for PPDs: the vertical shear instability (VSI), the related processes of convective overstability (COS) and subcritical baroclinic instability (SBI), and the zombie vortex instability (ZVI). A detailed discussion for each of the instabilities is beyond the scope of this review; readers are referred to ( 14 , 15 ) for further information. Here, we summarize the main requirements for each instability to operate, their possible existence in PPDs (see Fig.…”

Section: Theorymentioning

confidence: 99%

See 1 more Smart Citation

History of the solar nebula from meteorite paleomagnetism

Weiss

Bai

2021

Sci. Adv.

View full text Add to dashboard Cite

We review recent advances in our understanding of magnetism in the solar nebula and protoplanetary disks (PPDs). We discuss the implications of theory, meteorite measurements, and astronomical observations for planetary formation and nebular evolution. Paleomagnetic measurements indicate the presence of fields of 0.54 ± 0.21 G at ~1 to 3 astronomical units (AU) from the Sun and ≳0.06 G at 3 to 7 AU until >1.22 and >2.51 million years (Ma) after solar system formation, respectively. These intensities are consistent with those predicted to enable typical astronomically observed protostellar accretion rates of ~10−8M⊙year−1, suggesting that magnetism played a central role in mass transport in PPDs. Paleomagnetic studies also indicate fields <0.006 G and <0.003 G in the inner and outer solar system by 3.94 and 4.89 Ma, respectively, consistent with the nebular gas having dispersed by this time. This is similar to the observed lifetimes of extrasolar protoplanetary disks.

show abstract

Section: Theorymentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

History of the solar nebula from meteorite paleomagnetism

Weiss

Bai

2021

Sci. Adv.

View full text Add to dashboard Cite

show abstract

“…This however would require that a robust turbulence-driving mechanism unrelated to the MRI, such as a hydrodynamic instability, is excited in Keplerian discs. Such a mechanism, if any, remains elusive (Fromang & Lesur 2017).…”

Section: The Diverse Challenging Complexity Of Large-scale Dynamosmentioning

confidence: 99%

Dynamo theories

2019

View full text Add to dashboard Cite

These lecture notes are based on a tutorial given in 2017 at a plasma physics winter school in Les Houches. Their aim is to provide a self-contained graduate-student level introduction to the theory and modelling of the dynamo effect in turbulent fluids and plasmas, blended with a review of current research in the field. The primary focus is on the physical and mathematical concepts underlying different (turbulent) branches of dynamo theory, with some astrophysical, geophysical and experimental contexts disseminated throughout the document. The text begins with an introduction to the rationale, observational and historical roots of the subject, and to the basic concepts of magnetohydrodynamics relevant to dynamo theory. The next two sections discuss the fundamental phenomenological and mathematical aspects of (linear and nonlinear) small- and large-scale magnetohydrodynamic (MHD) dynamos. These sections are complemented by an overview of a selection of current active research topics in the field, including the numerical modelling of the geo- and solar dynamos, shear dynamos driven by turbulence with zero net helicity and MHD-instability-driven dynamos such as the magnetorotational dynamo. The difficult problem of a unified, self-consistent statistical treatment of small- and large-scale dynamos at large magnetic Reynolds numbers is also discussed throughout the text. Finally, an excursion is made into the relatively new but increasingly popular realm of magnetic-field generation in weakly collisional plasmas. A short discussion of the outlook and challenges for the future of the field concludes the presentation.

show abstract

“…For ∇ ad ∼ 0.285, and the opacity prescription of Bell & Lin (1994), this condition can be satisfied in large parts of the disk, including at 0.1 AU. While these models were set aside for a while due to conflicting numerical results (Klahr 2007), more recent studies, for example Rafikov (2007); Lesur & Ogilvie (2010) ;Fromang & Lesur (2019); Pfeil & Klahr (2019), showed that vertical convective instability in disks cannot yet be excluded as a plausible heat and angular momentum transport mechanism.…”

Section: The Effect Of Disk Entropy On Envelope Growthmentioning

confidence: 99%

The imprint of the protoplanetary disc in the accretion of super-Earth envelopes

Ali-Dib

Cumming

Lin

2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Super-Earths are by far the most dominant type of exoplanet, yet their formation is still not well understood. In particular, planet formation models predict that many of them should have accreted enough gas to become gas giants. Here we examine the role of the protoplanetary disk in the cooling and contraction of the protoplanetary envelope. In particular, we investigate the effects of 1) the thermal state of the disk as set by the relative size of heating by accretion or irradiation, and whether its energy is transported by radiation or convection, and 2) advection of entropy into the outer envelope by disk flows that penetrate the Hill sphere, as found in 3D global simulations. We find that, at 5 and 1 AU, this flow at the level reported in the non-isothermal simulations where it penetrates only to ∼ 0.3 times the Hill radius has little effect on the cooling rate since most of the envelope mass is concentrated close to the core, and far from the flow. On the other hand, at 0.1 AU, the envelope quickly becomes fullyradiative, nearly isothermal, and thus cannot cool down, stalling gas accretion. This effect is significantly more pronounced in convective disks, leading to envelope mass orders of magnitude lower. Entropy advection at 0.1 AU in either radiative or convective disks could therefore explain why super-Earths failed to undergo runaway accretion. These results highlight the importance of the conditions and energy transport in the protoplanetary disk for the accretion of planetary envelopes.

show abstract

Angular momentum transport in accretion disks: a hydrodynamical perspective

Cited by 25 publications

References 99 publications

History of the solar nebula from meteorite paleomagnetism

History of the solar nebula from meteorite paleomagnetism

Dynamo theories

The imprint of the protoplanetary disc in the accretion of super-Earth envelopes

Contact Info

Product

Resources

About