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arXiv 2309.02498astro-ph.GA
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茶杯星系中的复杂活动星系核反馈:强大的电离星系外流、喷流与星际介质相互作用,以及巨型气泡中活动星系核触发的恒星形成证据

Complex AGN feedback in the Teacup galaxy. A powerful ionised galactic outflow, jet-ISM interaction, and evidence for AGN-triggered star formation in a giant bubble

G. Venturi, E. Treister, C. Finlez, G. D'Ago, F. Bauer, C. M. Harrison, C. Ramos Almeida, M. Revalski, F. Ricci, L. F. Sartori, A. Girdhar, W. C. Keel, D. Tubín

AI总结:

该研究利用VLT/MUSE观测茶杯星系,发现电离外流与喷流共同作用,产生负反馈抑制恒星形成,同时在气泡边缘触发年轻恒星形成,展现正反馈,表明活动星系核反馈具有双重效应。

摘要:

红移约0.1的2型类星体J1430+1339(“茶杯”星系)是一个复杂的星系,展示出直径约10千秒差距的电离气体环、同空间的射电气泡、紧凑(约1千秒差距)的喷流以及外流活动。我们利用VLT/MUSE光学积分场光谱观测,表征了从千秒差距到数十千秒差距尺度上的星系电离外流的性质与影响,并将其与射电喷流的影响进行比较。我们探测到速度弥散增强(>300 km/s),该增强沿垂直于射电喷流、活动星系核电离瓣和快速外流的方向延伸数千米差距,类似于在其他拥有紧凑低功率喷流的星系中所发现的情况,表明喷流强烈扰动宿主星际介质。质量外流率随距星系核距离的增加而下降,从内部1-2千秒差距的约100太阳质量/年降至30千秒差距处的<0.1太阳质量/年。电离质量外流率约为分子外流率的1-8倍,这与活动星系核中通常引用的数值相反。多相外流的驱动因素可能是活动星系核辐射与喷流的结合。外流质量加载因子(约5-10)和分子气体耗尽时间(<10^8年)表明外流能显著影响星系中的恒星形成和气体储备。然而,能够逃逸暗物质晕势阱的电离外流部分可能可以忽略不计。我们探测到与电离气体环同空间的蓝色连续谱发射。在这里,恒星族群比星系其余部分(约0.5-1吉年)更年轻(<100-150百万年)。这构成了喷流和外流的压缩作用在气泡边缘触发恒星形成的可能证据(“正反馈”),正如理论所预测的那样。总而言之,茶杯星系构成一个丰富系统,其中来自外流和喷流的活动星系核反馈,无论是负反馈还是正反馈形式,共存其中。

英文摘要:

The $z$~0.1 type-2 QSO J1430+1339 (the 'Teacup') is a complex galaxy showing a loop of ionised gas ~10 kpc in diameter, co-spatial radio bubbles, a compact (~1 kpc) jet, and outflow activity. We used VLT/MUSE optical integral field spectroscopic observations to characterise the properties and effects of the galactic ionised outflow from kpc up to tens of kpc scales and compare them with those of the radio jet. We detect a velocity dispersion enhancement (>300 km/s) elongated over several kpc perpendicular to the radio jet, the AGN ionisation lobes, and the fast outflow, similar to what is found in other galaxies hosting compact, low-power jets, indicating that the jet strongly perturbs the host ISM. The mass outflow rate decreases with distance from the nucleus, from around 100 $M_\odot$/yr in the inner 1-2 kpc to <0.1 $M_\odot$/yr at 30 kpc. The ionised mass outflow rate is ~1-8 times higher than the molecular one, in contrast with what is often quoted in AGN. The driver of the multi-phase outflow is likely a combination of AGN radiation and the jet. The outflow mass-loading factor (~5-10) and the molecular gas depletion time (<10$^8$ yr) indicate that the outflow can significantly affect the star formation and the gas reservoir in the galaxy. However, the fraction of the ionised outflow that is able to escape the dark matter halo potential is likely negligible. We detect blue-coloured continuum emission co-spatial with the ionised gas loop. Here, stellar populations are younger (<100-150 Myr) than in the rest of the galaxy (~0.5-1 Gyr). This constitutes possible evidence for star formation triggered at the edge of the bubble due to the compressing action of the jet and outflow ('positive feedback'), as predicted by theory. All in all, the Teacup constitutes a rich system in which AGN feedback from outflows and jets, in both its negative and positive flavours, co-exist.

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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