PRODIGE – envelope to disk with NOEMA: I. A 3000 au streamer feeding a Class I protostar
PRODIGE – envelope to disk with NOEMA: I. A 3000 au streamer feeding a Class I protostar
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PRODIGE — 使用 NOEMA 将信封传输至磁盘：I. 一条 3000 au 的流光为 I 级原恒星供电
DOI：
10.1051/0004-6361/202243310
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发表时间：
2022
影响因子：
6.5
通讯作者：
Henning, Th.
中科院分区：
文献类型：
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作者：
Valdivia-Mena, M. T.;Pineda, J. E.;Segura-Cox, D. M.;Caselli, P.;Neri, R.;López-Sepulcre, A.;Cunningham, N.;Bouscasse, L.;Semenov, D.;Henning, Th.
背景在过去的几年里，对流光的探测有所增加，流光是指不对称的物质流向原恒星盘，物质来自恒星诞生核心之外。目前还不清楚它们是如何影响质量吸积过程的，特别是在0类阶段之外。目的我们研究了拥挤的恒星形成区域NGC 1333中的I类源PER-EMB-50周围的气体运动学。我们的目标是研究质量流入如何在这个来源从包层到磁盘尺度进行。方法我们使用新的NOEMA 1.3 mm观测，包括C18O，H_2CO，等，在Prodige MPG-IRAM计划的背景下，探索朝向PER-EMB-50的核心和包层结构。结果我们发现在H_2CO和C18O排放中，有一个流光向PER-EMB-50输送物质。流光的发射可以用沿流线的入射气体的解析解很好地描述，该流线的角动量是守恒的，无论是在像平面上还是在视线速度上。流光的平均下落速率为1.3x10−6M⊙yr−1，比原恒星目前的吸积速率高5到10倍。SO和SO2排放揭示了内包层中的非对称流入运动，以及每emb-50附近的流光。此外，SO2的存在可能标志着落入物质的撞击区。结论流光提供了足够的质量来维持原恒星的吸积率，并可能产生吸积暴，这可以解释原恒星相对于其他I类来源的高光度。我们的结果强调了晚期坠落对原恒星演化的重要性：流光可能在0级阶段之后为恒星吸积提供了大量的质量。
ContextIn the past few years, there has been a rise in the detection of streamers, asymmetric flows of material directed toward the protostellar disk with material from outside a star’s natal core. It is unclear how they affect the process of mass accretion, in particular beyond the Class 0 phase.AimsWe investigate the gas kinematics around Per-emb-50, a Class I source in the crowded star-forming region NGC 1333. Our goal is to study how the mass infall proceeds from envelope to disk scales in this source.MethodsWe use new NOEMA 1.3 mm observations, including C18O, H2CO, and SO, in the context of the PRODIGE MPG – IRAM program, to probe the core and envelope structures toward Per-emb-50.ResultsWe discover a streamer delivering material toward Per-emb-50 in H2CO and C18O emission. The streamer’s emission can be well described by the analytic solutions for an infalling parcel of gas along a streamline with conserved angular momentum, both in the image plane and along the line-of-sight velocities. The streamer has a mean infall rate of 1.3 × 10−6M⊙yr−1, five to ten times higher than the current accretion rate of the protostar. SO and SO2emission reveal asymmetric infall motions in the inner envelope, additional to the streamer around Per-emb-50. Furthermore, the presence of SO2could mark the impact zone of the infalling material.ConclusionsThe streamer delivers sufficient mass to sustain the protostellar accretion rate and might produce an accretion burst, which would explain the protostar’s high luminosity with respect to other Class I sources. Our results highlight the importance of late infall for protostellar evolution: streamers might provide a significant amount of mass for stellar accretion after the Class 0 phase.