期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 478, 期 2, 页码 2700-2722出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/sty984
关键词
accretion, accretion discs; protoplanetary discs; circumstellar matter; stars: kinematics and dynamics; stars: pre-main-sequence
资金
- Science and Technology Facilities Council (STFC)
- Imperial College Junior Research Fellowship
- DISCSIM project - European Research Council under ERC-2013-ADG [341137]
- STFC [1644105] Funding Source: UKRI
Most stars form and spend their early life in regions of enhanced stellar density. Therefore, the evolution of protoplanetary discs (PPDs) hosted by such stars are subject to the influence of other members of the cluster. Physically, PPDs might be truncated either by photoevaporation due to ultraviolet flux from massive stars, or tidal truncation due to close stellar encounters. Here we aim to compare the two effects in real cluster environments. In this vein we first review the properties of well-studied stellar clusters with a focus on stellar number density, which largely dictates the degree of tidal truncation, and far-ultraviolet (FUV) flux, which is indicative of the rate of external photoevaporation. We then review the theoretical PPD truncation radius due to an arbitrary encounter, additionally taking into account the role of eccentric encounters that play a role in hot clusters with a 1D velocity dispersion sigma(v) greater than or similar to 2 kms(-1). Our treatment is then applied statistically to varying local environments to establish a canonical threshold for the local stellar density (n(c) greater than or similar to 10(4) pc(-3)) for which encounters can play a significant role in shaping the distribution of PPD radii over a time-scale similar to 3Myr. By combining theoretical mass-loss rates due to FUV flux with viscous spreading in a PPD, we establish a similar threshold for which a massive disc is completely destroyed by external photoevaporation. Comparing these thresholds in local clusters, we find that if either mechanism has a significant impact on the PPD population then photoevaporation is always the dominating influence.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据