arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2301.03387astro-ph.SRastro-ph.GA
收藏

FUor型恒星分子外流的APEX研究

An APEX study of molecular outflows in FUor-type stars

Fernando Cruz-Sáenz de Miera, Ágnes Kóspál, Péter Ábrahám, Timea Csengeri, Orsolya Féher, Rolf Güsten, Thomas Henning

备注：
Accepted for publication in ApJ. 29 pages, 8 tables, 10 figures, 2 figuresets
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

猎户座FU型天体（FUors）是低质量的前主序星天体，它们经历了一个短寿命阶段（约100年），质量吸积速率增加（从10^-8到10^-4 M_sun/年^-1）。这些爆发的年轻恒星处于恒星演化的早期阶段，因此，仍然深深地嵌入到一个巨大的包层中，这个包层为星周盘提供物质，然后被吸积到恒星上。一些FUOR驱动分子外流，即低速广角磁流体动力风，将能量和动量注入周围的包层，并帮助清除年轻恒星周围的物质。本文报道了用APEX观测的20颗FUor型爆发年轻星的~（12）CO（3 - 2），~（13）CO（3- 2）和~（12）CO（4- 3）测量结果。我们用我们的~（13）CO（3- 2）观测值来测量每个FUor周围包层的质量，并发现与从10 μ m硅酸盐特征中发现的FUor演化趋势一致。我们发现在11个FUOR流出，计算它们的质量和其他运动学性质，并比较这些与周围的静态年轻恒星物体从文献中收集的流出。这种比较表明，流出的FUOR更大的流量比流出的静态源，和FUOR流出有一个较高的比率流出质量相对于信封比静态样品，这表明爆发的年轻恒星有较低的恒星形成效率。最后，我们发现，在FUOR流出力是类似的静态年轻恒星的对象，表明它们的吸积历史是相似的，或者说，FUOR流出具有较低的速度。

英文摘要：

FU Orionis-type objects (FUors) are low-mass pre-main-sequence objects which go through a short-lived phase (~100 years) of increased mass accretion rate (from 10^-8 to 10^-4 M_sun yr^-1). These eruptive young stars are in the early stages of stellar evolution and, thus, still deeply embedded in a massive envelope that feeds material to the circumstellar disk that is then accreted onto the star. Some FUors drive molecular outflows, i.e. low-velocity wide-angle magneto-hydrodynamical winds, that inject energy and momentum back to the surrounding envelopes, and help clear the material surrounding the young star. Here we present a 12CO (3--2), 13CO (3--2) and 12CO (4--3) survey of 20 FUor-type eruptive young stars observed with APEX. We use our 13CO (3--2) observations to measure the masses of the envelopes surrounding each FUor and find an agreement with the FUor evolutionary trend found from the 10um silicate feature. We find outflows in 11 FUors, calculate their masses and other kinematic properties, and compare these with those of outflows found around quiescent young stellar objects gathered from the literature. This comparison indicates that outflows in FUors are more massive than outflows in quiescent sources, and that FUor outflows have a higher ratio outflow mass with respect to the envelope than the quiescent sample, indicating that the eruptive young stars have lower star-forming efficiencies. Finally, we found that the outflow forces in FUors are similar to those of quiescent young stellar objects, indicating that their accretion histories are similar or that the FUor outflows have lower velocities.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑