Axisymmetric disks of high eccentricity, low mass bodies on near-Keplerian orbits are unstable to an out-of-plane buckling. This "inclination instability" exponentially grows the orbital inclinations, raises perihelia distances and clusters in argument of perihelion. Here we examine the instability in a massive primordial scattered disk including the orbit-averaged gravitational influence of the giant planets. We show that differential apsidal precession induced by the giant planets will suppress the inclination instability unless the primordial mass is $\gtrsim 20$ Earth masses. We also show that the instability should produce a "perihelion gap" at semi-major axes of hundreds of AU, as the orbits of the remnant population are more likely to have extremely large perihelion distances ($\mathcal{O}(100~\rm{AU})$) than intermediate values.
Today, Pluto and Eris are the largest and most massive Trans-Neptunian Objects respectively. They are believed to be the last remnants of a population of planetesimals that has been reduced by >99% since the time of its formation. This reduction implies a primordial population of hundreds or thousands of Pluto-mass objects, and a mass-number distribution that could have extended to hundreds of Lunas, dozens of Mars, and several Earths. Such lost protoplanets would have left signatures in the dynamics of the present-day Trans-Neptunian Populations, and we statistically limit their primordial nu…
The Primordial Disk of small icy planetesimals, once located at 15-30 AU from the Sun, was disrupted by giant planet migration in the early Solar System. The Primordial Disk thereby became the source region of objects in the current-day Kuiper Belt, Scattered Disk, and Oort Cloud. I present the thermophysics code "Numerical Icy Minor Body evolUtion Simulator", or NIMBUS, and use it to study the thermophysical evolution of planetesimals in the Primordial Disk prior to its disruption. Such modelling is mandatory in order to understand the behaviour of dynamically new comets from the Oort Cloud, …
We investigate the origins of the photometrically Very Red and Less Red Trans-Neptunian Objects. We first reanalyse the dataset of Marsset et al. 2019 and find that, in addition to the known color-inclination correlation in hot TNOs, a similar trend exists for color-eccentricity. We show that VR TNOs are sharply constrained to eccentricities < 0.42 and inclinations < 21 deg, leading to a paucity of VR scattered disk and distant MMR objects. We then interpret these findings using N-body simulations accounting for Neptune's outward migration into a massless particles disk, and find that these ob…
The TRAPPIST-1 system is unique in that it has a chain of seven terrestrial Earth-like planets located close to or in its habitable zone. In this paper, we study the effect of potential cometary impacts on the TRAPPIST-1 planets and how they would affect the primordial atmospheres of these planets. We consider both atmospheric mass loss and volatile delivery with a view to assessing whether any sort of life has a chance to develop. We ran N-body simulations to investigate the orbital evolution of potential impacting comets, to determine which planets are more likely to be impacted and the dist…
Compact dust concentration in the MWC 758 protoplanetary disk
星子的形成需要原始尘埃颗粒从微米到公里大小的物体。由气体压力最大值引起的尘埃陷阱被认为是颗粒可以集中并快速生长以形成星子的区域，然后径向迁移到恒星上。我们报告新的VLA Ka & Ku观测的原行星盘周围的赫比格Ae/Be星MWC 758。Ka图像显示了一个紧凑的发射区域，在外盘表明一个强大的集中的大尘埃颗粒。追踪较小的颗粒，ALMA档案数据在波段7连续显示扩展磁盘发射强度最大的西北部的中央恒星，这符合VLA的丛位置。在尘埃捕获的背景下，预计紧凑的Ka发射，因为大颗粒比小颗粒更容易被捕获在气体压力最大值。我们开发了一个非轴对称的参数模型的启发，一个稳定状态的涡解与参数充分选择重现的意见，包括光谱能量分布。最后，我们将射电连续谱与SPHERE散射光数据进行了比较。ALMA连续体在空间上与散射光中看到的螺旋状特征相吻合，而VLA团块与散射光最大值相偏移。此外，ALMA图显示了与没有散射偏振发射的区域相匹配的递减。在不同波长的连续观测是必要的，以得出结论，如果VLA-ALMA差异是一个不透明度或真正的灰尘分离。
Axisymmetric disks of eccentric orbits in near-Keplerian potentials are unstable to an out-of-plane buckling. Recently, Zderic et al. (2020) showed that an idealized disk saturates to a lopsided mode. Here we show that this apsidal clustering also occurs in a primordial scattered disk in the outer solar system which includes the orbit-averaged gravitational influence of the giant planets. We explain the dynamics using Lynden-Bell (1979)'s mechanism for bar formation in galaxies. We also show surface density and line of sight velocity plots at different times during the instability, highlightin…
X-ray- and EUV- (XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may crucially impact disk evolution, affecting both gas and dust distributions. We constrain the dust densities in a typical XEUV-driven outflow, and determine whether these winds can be observed at $μ\mathrm{m}$-wavelengths in scattered and polarised light. For an XEUV-driven outflow around a $M_* = 0.7\,\mathrm{M}_\odot$ T-Tauri star with $L_X = 2 \cdot 10^{30}\,\mathrm{erg/s}$, we find a dust mass-loss rate $\dot{M}_\mathrm{dust} \lesssim 4.1 \cdot 10^{-11}\,\mathrm{M_\odot / yr}$…
Despite rapidly growing disk observations, it remains a mystery what primordial dust aggregates look like and what the physical and chemical properties of their constituent grains (monomers) are in young planet-forming disks. Confrontation of models with observations to answer this mystery has been a notorious task because we have to abandon a commonly used assumption, perfectly spherical grains, and take into account particles with complex morphology. In this Letter, we present the first thorough comparison between near-infrared scattered light of the young planet-forming disk around IM Lup a…
The Birth of Minor-Body Populations in the $β$ Pictoris System I: The First 25 Myr
Universidad de La Laguna (ULL)（拉古纳大学）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），CSIC-INTA）；Universidad Complutense de Madrid（马德里康普顿斯大学）；Lund University（隆德大学）
We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the HiCIAO and SCExAO/CHARIS instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0.65 (66 AU) and extends out to 0.98 (100 AU) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW- and SE- side of the disk exhibiting similar intensities. Our data are clearly different than 2016 epoch H-band observations from VLT/S…
