Numerical simulations of protostellar encounters - II. Coplanar disc-disc encounters

Watkins, S. J.; Bhattal, A. S.; Boffin, H. M. J.; Francis, N.; Whitworth, Anthony Peter

doi:10.1046/j.1365-8711.1998.01987.x

Cited by 38 publications

(9 citation statements)

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“…One issue that has gained surprisingly little attention in the past is the role of gravitational interactions between the disc and passing stars within the young host stellar cluster. Since stars are generally born in clusters (Forgan & Rice 2009), rather than as isolated objects, star-disc and disc-disc interactions (Boffin et al 1998;Watkins et al 1998a;Pfalzner et al 2005;Thies et al 2005) probably play an important role for the dynamical evolution of such discs and thus for massive planet and BD formation through fragmentation of the discs.…”

Section: Introductionmentioning

confidence: 99%

Tidally Induced Brown Dwarf and Planet Formation in Circumstellar Disks

Thies

Kroupa

Goodwin

et al. 2010

ApJ

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Most stars are born in clusters and the resulting gravitational interactions between cluster members may significantly affect the evolution of circumstellar disks and therefore the formation of planets and brown dwarfs (BDs). Recent findings suggest that tidal perturbations of typical circumstellar disks due to close encounters may inhibit rather than trigger disk fragmentation and so would seem to rule out planet formation by external tidal stimuli. However, the disk models in these calculations were restricted to disk radii of 40 AU and disk masses below 0.1 M . Here, we show that even modest encounters can trigger fragmentation around 100 AU in the sorts of massive (∼0.5 M ), extended ( 100 AU) disks that are observed around young stars. Tidal perturbation alone can do this; no disk-disk collision is required. We also show that very low mass binary systems can form through the interaction of objects in the disk. In our computations, otherwise non-fragmenting massive disks, once perturbed, fragment into several objects between about 0.01 and 0.1 M , i.e., over the whole BD mass range. Typically, these orbit on highly eccentric orbits or are even ejected. While probably not suitable for the formation of Jupiter-or Neptune-type planets, our scenario provides a possible formation mechanism for BDs and very massive planets which, interestingly, leads to a mass distribution consistent with the canonical substellar initial mass function. As a minor outcome, a possible explanation for the origin of misaligned extrasolar planetary systems is discussed.

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Section: Introductionmentioning

confidence: 99%

Tidally Induced Brown Dwarf and Planet Formation in Circumstellar Disks

Thies

Kroupa

Goodwin

et al. 2010

ApJ

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“…For example, if sub-stellar objects form by different processes than hydrogen-burning stars such as ejection of stellar embryos (e.g. Bate et al 2003;Reipurth & Clarke 2001) or erosion of star-forming clouds by radiation from massive stars (Watkins et al 1998), then the disks may be proportionally smaller than those around higher mass objects.…”

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confidence: 99%

Dust Masses of Disks Around 8 Brown Dwarfs and Very Low-Mass Stars in Upper Sco Ob1 and Ophiuchus

Plas

Ménard

Ward-Duong

et al. 2016

ApJ

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We present the results of ALMA band 7 observations of dust and CO gas in the disks around 7 objects with spectral types ranging between M5.5 and M7.5 in Upper Scorpius OB1, and one M3 star in Ophiuchus. We detect unresolved continuum emission in all but one source, and the 12 CO J=3-2 line in two sources. We constrain the dust and gas content of these systems using a grid of models calculated with the radiative transfer code MCFOST, and find disk dust masses between 0.1 and 1 M ⊕ , suggesting that the stellar mass / disk mass correlation can be extrapolated for brown dwarfs with masses as low as 0.05 M ⊙ . The one disk in Upper Sco in which we detect CO emission, 2MASS J15555600, is also the disk with warmest inner disk as traced by its H -[4.5] photometric color. Using our radiative transfer grid, we extend the correlation between stellar luminosity and mass-averaged disk dust temperature originally derived for stellar mass objects to the brown dwarf regime to T dust ≈ 22(L * /L ⊙ ) 0.16 K, applicable to spectral types of M5 and later. This is slightly shallower than the relation for earlier spectral type objects and yields warmer low-mass disks. The two prescriptions cross at 0.27 L ⊙ , corresponding to masses between 0.1 and 0.2 M ⊙ depending on age.

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“…The single stars, the multiple star systems and the planets form in co-planar protostellar disks (e.g. Watkins et al, 1998). If the orbital plane of a third body is not co-planar with, or perpendicular to, the orbital plane of the central EB, periodic long-term perturbations change the orbital plane of the central EB, and the eclipses may no longer occur (Soderhjelm, 1975, Eq.…”

Section: Astrophysicsmentioning

confidence: 99%

About ten stars orbit eclipsing binary XZ And

Jetsu

2020

Preprint

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A third body in an eclipsing binary system causes regular periodic changes in the observed (O) minus the computed (C) eclipse epochs. Fourth bodies have rarely been detected from the O-C data. We apply the new Discrete Chi-square Method (DCM) to the O-C data of the eclipsing binary XZ Andromedae. These data contain the periodic signatures of at least ten wide orbit stars (WOSs). Their orbital periods are between 1.6 and 91.7 years. Since no changes have been observed in the eclipses of XZ And during the past 127 years, the orbits of all these WOSs are most probably co-planar. We give detailed instructions of how the professional and the amateur astronomers can easily repeat all stages of our DCM analysis with an ordinary PC, as well as apply this method to the O-C data of other eclipsing binaries.

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Numerical simulations of protostellar encounters - II. Coplanar disc-disc encounters

Cited by 38 publications

References 0 publications

Tidally Induced Brown Dwarf and Planet Formation in Circumstellar Disks

Tidally Induced Brown Dwarf and Planet Formation in Circumstellar Disks

Dust Masses of Disks Around 8 Brown Dwarfs and Very Low-Mass Stars in Upper Sco Ob1 and Ophiuchus

About ten stars orbit eclipsing binary XZ And

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