From dust to planets – I. Planetesimal and embryo formation
From dust to planets – I. Planetesimal and embryo formation
复制标题
从尘埃到行星——一、星子和胚胎形成
DOI：
--
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
G. Coleman
中科院分区：
文献类型：
--
作者：
G. Coleman
行星形成模型开始与原胚胎和星子已经完全形成，错过了一个关键的步骤，形成星子/原胚胎。在这项工作中，我们包括处方的星子和原生胚胎形成所产生的鹅卵石被困在短暂的压力颠簸，在热演化的粘性盘检查整个磁盘的原生胚胎和星子的大小和分布。我们发现，微行星的大小随着轨道距离的增加而增加，从距离星星10公里到几百公里。原始胚胎的质量也随着轨道半径的增加而增加，从冰线周围的10 ^{-6}{\，{\rm M}_{\oplus }}$到冥王星轨道附近的10 ^{-3}{\，{\rm M}_{\oplus }}$。我们包括卵石和星子吸积的处方，以检查原始胚胎可以达到的质量。在靠近星星的地方，由于小的星子，星子的吸积是有效的，而卵石的吸积是有效的，卵石的大小是碎片有限的，但效率低下时，漂移为主，由于低吸积率之前，卵石供应减少。在冰线外，由于星子离心率的增加，星子吸积变得效率低下，而卵石吸积随着初始原胚质量的增加而变得更加有效，使它们在卵石供应耗尽之前显着增长。结合这两种情况可以在更大的距离更大的原始胚胎，因为星子的吸积允许卵石吸积变得更有效，允许巨大的行星核心形成的距离高达10 {\，{\rm Au}}$。通过包括更现实的初始原始胚胎和星子大小，以及合并的吸积场景，应该可以更完整地了解行星和行星系统如何形成的开始到结束的过程。
Planet formation models begin with proto-embryos and planetesimals already fully formed, missing out a crucial step, the formation of planetesimals/proto-embryos. In this work, we include prescriptions for planetesimal and proto-embryo formation arising from pebbles becoming trapped in short-lived pressure bumps, in thermally evolving viscous discs to examine the sizes and distributions of proto-embryos and planetesimals throughout the disc. We find that planetesimal sizes increase with orbital distance, from ∼10 km close to the star to hundreds of kilometres further away. Proto-embryo masses are also found to increase with orbital radius, ranging from $10^{-6}{\, {\rm M}_{\oplus }}$ around the iceline, to $10^{-3}{\, {\rm M}_{\oplus }}$ near the orbit of Pluto. We include prescriptions for pebble and planetesimal accretion to examine the masses that proto-embryos can attain. Close to the star, planetesimal accretion is efficient due to small planetesimals, whilst pebble accretion is efficient where pebble sizes are fragmentation limited, but inefficient when drift dominated due to low accretion rates before the pebble supply diminishes. Exterior to the iceline, planetesimal accretion becomes inefficient due to increasing planetesimal eccentricities, whilst pebble accretion becomes more efficient as the initial proto-embryo masses increase, allowing them to significantly grow before the pebble supply is depleted. Combining both scenarios allows for more massive proto-embryos at larger distances, since the accretion of planetesimals allows pebble accretion to become more efficient, allowing giant planet cores to form at distances upto $10{\, {\rm au}}$. By including more realistic initial proto-embryo and planetesimal sizes, as well as combined accretion scenarios, should allow for a more complete understanding in the beginning to end process of how planets and planetary systems form.
DOI：
10.1111/j.1745-3933.2012.01243.x
发表时间：
2012-02
期刊：
--
影响因子：
--
作者：
Richard Alexander;I. Pascucci
通讯作者：
Richard Alexander;I. Pascucci
DOI：
10.1088/0004-637x/804/1/29
发表时间：
2015-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
U. Gorti;D. Hollenbach;C. Dullemond
通讯作者：
U. Gorti;D. Hollenbach;C. Dullemond
影响因子：
4.8
作者：
T. Haworth;C. Clarke;Wahidur Rahman;A. Winter;S. Facchini
通讯作者：
T. Haworth;C. Clarke;Wahidur Rahman;A. Winter;S. Facchini