论文标题
大规模早期类型星系中出色的初始质量功能变化：氘丰度的潜在作用
Stellar initial mass function variation in massive early-type galaxies: the potential role of the deuterium abundance
论文作者
论文摘要
观察到的恒星初始质量功能（IMF）似乎有所不同，在最庞大，金属富含的早期型星系的中心变为底部。目前尚不清楚哪些物理过程可能导致IMF变化。在本文中，我们证明了形成恒星的出生云中氘的丰度对于设定IMF可能很重要。我们在低质量原恒星上使用圆盘积聚模型，以表明那些由氘贫困气体形成的人的零元序列质量预计将明显低于原始（高氘级分）材料形成的质量。在我们的简单模型中，这种氘丰度的效果取决于恒星质量，因此所得的IMF将变得较低 - 如观测中所见。恒星质量损失完全不含氘，对于在宇宙时间内加油恒星形成很重要。使用Eagle模拟，我们表明，在观察到IMF变化的相同区域中，恒星质量损失引起的氘的变化最强：在最大，金属丰富，被动星系的中心。尽管我们的分析无法证明氘的丰度是观察到的IMF变化的根本原因，但它为未来的理论和观察性尝试研究了这种可能性奠定了基础。
The observed stellar initial mass function (IMF) appears to vary, becoming bottom-heavy in the centres of the most massive, metal-rich early-type galaxies. It is still unclear what physical processes might cause this IMF variation. In this paper, we demonstrate that the abundance of deuterium in the birth clouds of forming stars may be important in setting the IMF. We use models of disc accretion onto low-mass protostars to show that those forming from deuterium-poor gas are expected to have zero-age main sequence masses significantly lower than those forming from primordial (high deuterium fraction) material. This deuterium abundance effect depends on stellar mass in our simple models, such that the resulting IMF would become bottom-heavy - as seen in observations. Stellar mass loss is entirely deuterium-free and is important in fuelling star formation across cosmic time. Using the EAGLE simulation we show that stellar mass loss-induced deuterium variations are strongest in the same regions where IMF variations are observed: at the centres of the most massive, metal-rich, passive galaxies. While our analysis cannot prove that the deuterium abundance is the root cause of the observed IMF variation, it sets the stage for future theoretical and observational attempts to study this possibility.
