X-ray and UV radiation in the planet-forming T-Tauri system PDS 70. Signs of accretion and coronal activity
arxiv(2024)
摘要
Planet formation takes place in protoplanetary discs around young T-Tauri
stars. PDS 70 is one of the first confirmed examples of a system where the
planets are currently forming in gaps in the disc, and can be directly imaged.
One of the main early influences on planet formation is the lifetime of the
protoplanetary disk, which is limited by the intense stellar X-ray and UV
radiation. Stellar coronal activity and accretion of material onto the star are
both potential sources of XUV radiation. Previous Swift observations
detected UV emission, which were consistent with a low rate of accretion. We
present follow up observations with the XMM-Newton observatory, which observed
PDS 70 simultaneously in X-ray and UV in order to determine intensity of XUV
radiation in the system, and identify if the source is coronal, accretion, or
both. We detect a strong source in both X-ray and UV, with an average X-ray
0.2-12 keV luminosity of 1.37×10^30 erg s^-1, and a
possible flare which increased the luminosity to 2.8×10^30erg s^-1. The UV flux density is in excess of what would be
expected from chromospheric emission, and supports the interpretation that PDS
70 has continuing weak accretion less than ∼10^-10 M_⊙yr^-1. The implications of the detected X-ray and UV radiation are that the
disc is likely to be in the final stages of dispersal, and will be completely
evaporated in the next million years, bringing an end to the primary planet
formation process.
更多查看译文
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要