论文标题
星形核心对质量积聚率的环境影响
Environmental Effects of Star-Forming Cores on Mass Accretion Rate
论文作者
论文摘要
我们计算嵌入在不同信封中的云核的演变，以研究对质量积聚速率的环境影响。作为初始状态，我们忽略了磁场和云旋转，并采用由两个部分组成的恒星形成核心：中央凝结的核心和外膜。内核具有关键的邦诺 - 耶伯特密度曲线，并由外膜包围。我们准备15个具有不同外膜密度和重力半径的恒星形成核，其中气体流入塌陷的核心，并计算其演变，直到protostar形成后$ \ sim 2 \ sim 2 \ times10^5 $ yr。当外膜密度较低时，随着芯的耗尽，质量积聚率降低。相比之下，当外膜密度高时，质量吸积率会暂时提高，并且所得的原恒星质量超过了中央凝固的核心的初始质量。最近的一些观察结果表明，Prestellar核心的质量太小，无法重现出色的质量分布。我们的模拟表明，当将核心嵌入高密度的包膜中时，核心外部的质量流入对原始的质量增长有很大贡献，这可以解释最近的观察结果。
We calculate the evolution of cloud cores embedded in different envelopes to investigate environmental effects on the mass accretion rate onto protostars. As the initial state, we neglect the magnetic field and cloud rotation, and adopt star-forming cores composed of two parts: a centrally condensed core and an outer envelope. The inner core has a critical Bonnor-Ebert density profile and is enclosed by the outer envelope. We prepare 15 star-forming cores with different outer envelope densities and gravitational radii, within which the gas flows into the collapsing core, and calculate their evolution until $\sim 2 \times10^5$ yr after protostar formation. The mass accretion rate decreases as the core is depleted when the outer envelope density is low. In contrast, the mass accretion rate is temporarily enhanced when the outer envelope density is high and the resultant protostellar mass exceeds the initial mass of the centrally condensed core. Some recent observations indicate that the mass of prestellar cores is too small to reproduce the stellar mass distribution. Our simulations show that the mass inflow from outside the core contributes greatly to protostellar mass growth when the core is embedded in a high-density envelope, which could explain the recent observations.
