Formation, orbital and thermal evolution, and survival of planetary-mass clumps in the early phase of circumstellar disc evolution
Formation, orbital and thermal evolution, and survival of planetary-mass clumps in the early phase of circumstellar disc evolution
复制标题
星周盘演化早期阶段行星质量团的形成、轨道和热演化以及生存
DOI：
10.1093/mnras/stt1684
复制
发表时间：
2013
影响因子：
4.8
通讯作者：
S
中科院分区：
文献类型：
--
作者：
Tsukamoto;Yusuke;Machid a;M. N.;Inutsuka;S
我们报告了我们对坍塌的非磁化分子云核的三维辐射流体动力学模拟的结果。我们研究了星周盘的形成和演化以及由盘碎片形成的团块。我们的模拟表明，圆盘破碎发生在星周圆盘演化的早期阶段，形成了许多团块。在中心温度（tc > 100 K）和中心温度（tc > 100 K）下，团块可以用指数为n ~ 3和n￣4的多相球来表示。我们从数值和理论上证明，团块的最大质量是~ 0.03 M⊙，超过这个质量就不可避免地坍塌。团块的熵在演化过程中增加，这意味着演化主要是由盘的质量吸积而不是由辐射冷却决定的。尽管大多数团块迅速向内迁移并最终落在原恒星上，但仍有少数团块留在圆盘中。残存团块的中心密度和温度迅速升高，团块形成后1000-2000年内发生第二次崩塌。在我们的模拟中，形成了三个质量为0.2 M⊙、0.15 M⊙和0.06 M⊙的秒核。它们是原恒星或褐矮星，而不是原行星。为了使团块作为行星质量的物体存活下来，应该通过某些机制来阻止快速的质量吸积。
We report the results of our three-dimensional radiation hydrodynamics simulation of collapsing unmagnetized molecular cloud cores. We investigate the formation and evolution of the circumstellar disc and the clumps formed by disc fragmentation. Our simulation shows that disc fragmentation occurs in the early phase of circumstellar disc evolution and many clumps form. The clump can be represented by a polytrope sphere of indexn∼ 3 andn≳ 4 at central temperatureTc≲ 100 K andTc≳ 100 K, respectively. We demonstrate, numerically and theoretically, that the maximum mass of the clump, beyond which it inevitably collapses, is ∼0.03 M⊙. The entropy of the clump increases during its evolution, implying that evolution is chiefly determined by mass accretion from the disc rather than by radiative cooling. Although most of the clumps rapidly migrate inward and finally fall on to the protostar, a few clumps remain in the disc. The central density and temperature of the surviving clump rapidly increase and the clump undergoes a second collapse within 1000–2000 years after its formation. In our simulation, three second cores of masses 0.2 M⊙, 0.15 M⊙and 0.06 M⊙formed. These are protostars or brown dwarfs rather than protoplanets. For the clumps to survive as planetary-mass objects, the rapid mass accretion should be prevented by some mechanisms.
登录
查看更多内容
DOI：
10.1111/j.1745-3933.2005.00105.x
发表时间：
2005
影响因子：
--
作者：
W. Rice;G. Lodato;P. Armitage
通讯作者：
P. Armitage
平滑粒子磁流体动力学欧姆耗散的显式方案
影响因子：
4.8
作者：
Tsukamoto;Yusuke;Iwasaki;K;Inutsuka;S
通讯作者：
S
“超级地球”核心输送从约 100 个天文单位到约 8 个天文单位的数值模拟
DOI：
10.1111/j.1365-2966.2011.18953.x
发表时间：
2010
期刊：
Scopus
影响因子：
--
作者：
Seung;S. Nayakshin
通讯作者：
S. Nayakshin
影响因子：
6.5
作者：
P. Hennebelle;Andrea Ciardi
通讯作者：
P. Hennebelle;Andrea Ciardi
DOI：
10.1088/0004-637x/729/1/42
发表时间：
2011-01
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Machida;S. Inutsuka;Tomoaki Matsumoto
通讯作者：
M. Machida;S. Inutsuka;Tomoaki Matsumoto