论文标题
大多数恒星（和行星？）出生于强烈的辐射场
Most Stars (and Planets?) Are Born in Intense Radiation Fields
论文作者
论文摘要
原恒星和年轻的恒星在其出生巨型分子云（GMC）中的空间上强烈“聚集”或“相关”。我们证明了这种聚类导致这样的结论，即在随机的年轻恒星/光盘上的入射辐射辐射通量增强了（相对于体积平均磁通量），而该因子随着复合物的总恒星质量而增加。由于银河系质量功能是最高的，所以我们星系中的典型恒星经历了比在附近（但相对较小）云中形成的辐射环境要强得多，超过了Orion Nebular nebular群集中的通量，这是$ \ gtrsim $ 30的因素。在$ \ sim 50 \，$ au的外部辐射中，围绕年轻恒星的中间光盘加热围绕年轻恒星的加热。而且，如果圆盘没有被环境灰尘释放，则外部UV辐射可以在宿主恒星上占主导地位，直至sub-au尺度。恒星聚类的另一个结果是，入射通量的全星系范围内分布极为广泛（跨越$> 10美元），一半的银河恒星形成在一个实质性的“尾巴”上，朝着更强烈的背景辐射。我们还表明，在高密度环境（例如银河中心，星爆或高红移星系）中，外部照射的强度会扩大超线性。
Protostars and young stars are strongly spatially "clustered" or "correlated" within their natal giant molecular clouds (GMCs). We demonstrate that such clustering leads to the conclusion that the incident bolometric radiative flux upon a random young star/disc is enhanced (relative to volume-averaged fluxes) by a factor which increases with the total stellar mass of the complex. Because the Galactic cloud mass function is top-heavy, the typical star in our Galaxy experienced a much stronger radiative environment than those forming in well-observed nearby (but relatively small) clouds, exceeding fluxes in the Orion Nebular Cluster by factors of $\gtrsim$30. Heating of the circumstellar disc around a median young star is dominated by this external radiation beyond $\sim 50\,$AU. And if discs are not well-shielded by ambient dust, external UV irradiation can dominate over the host star down to sub-AU scales. Another consequence of stellar clustering is an extremely broad Galaxy-wide distribution of incident flux (spanning $>10$ decades), with half the Galactic star formation in a substantial "tail" towards even more intense background radiation. We also show that the strength of external irradiation is amplified super-linearly in high-density environments such as the Galactic centre, starbursts, or high-redshift galaxies.
