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arXiv 1806.03311astro-ph.GA
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银河系外流中广泛的恒星形成

Widespread star formation inside galactic outflows

R. Gallagher, R. Maiolino, F. Belfiore, N. Drory, R. Riffel, R. A. Riffel

摘要:

有几个模型预测,恒星可以在星系外流中形成,这将是星系演化的一种新的主要模式。对银河系外流的观测显示,它们拥有大量致密的分子气体,这些气体为恒星的形成提供了合适的条件。利用大型MANGA-SDSS 4星系巡天的积分场光谱数据,我们研究了大样本星系外流的性质。我们发现,在我们的样本中,恒星形成发生在至少一半的银河系外流内部。我们还表明,即使恒星形成是突出的许多其他星系外流内,这可能还没有被发现,因为诊断很容易被控制的存在,甚至微弱的活动星系核和冲击。如果遥远星系和类星体的典型大质量外流遵循当地观察到的相同的标度关系,那么在高z外流内的恒星形成可以高达几百兆太阳/年,并可能大大有助于星系球状体成分的早期形成。流出流中的恒星形成也可能有助于建立黑洞与其宿主球体之间的标度关系。此外,在大轨道上爆炸的超新星可以在原地进行化学浓缩,并加热环星系和星系际介质。最后,在大轨道上被抛出的年轻恒星也可能有助于宇宙的再电离。

英文摘要:

Several models have predicted that stars could form inside galactic outflows and that this would be a new major mode of galaxy evolution. Observations of galactic outflows have revealed that they host large amounts of dense and clumpy molecular gas, which provide conditions suitable for star formation. We have investigated the properties of the outflows in a large sample of galaxies by exploiting the integral field spectroscopic data of the large MaNGA-SDSS4 galaxy survey. We find that star formation occurs inside at least half of the galactic outflows in our sample. We also show that even if star formation is prominent inside many other galactic outflows, this may have not been revealed as the diagnostics are easily dominated by the presence of even faint AGN and shocks. If very massive outflows typical of distant galaxies and quasars follow the same scaling relations observed locally, then the star formation inside high-z outflows can be up to several 100 Msun/yr and could contribute substantially to the early formation of the spheroidal component of galaxies. Star formation in outflows can also potentially contribute to establishing the scaling relations between black holes and their host spheroids. Moreover, supernovae exploding on large orbits can chemically enrich in-situ and heat the circumgalactic and intergalactic medium. Finally, young stars ejected on large orbits may also contribute to the reionization of the Universe.

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。

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