ALMA揭示IRAS 16119--5048中的爆炸性外流候选体
ALMA Reveals an Explosive Outflow Candidate in IRAS 16119--5048
AI总结：
利用ALMA等多波段数据，在IRAS 16119-5048中发现16个汇聚流状结构和27个致密核，提出其可能为低能量爆炸性外流候选体，并探讨了触发机制。
AI中文摘要：
我们利用ALMA ATOMS Band 3和QUARKS Band 6观测，结合档案ATCA射电连续谱和Spitzer中红外数据，对大质量恒星形成区域IRAS 16119-5048（I16119）进行了多波段研究。CO (2-1)发射揭示了中心区域周围的高速流状结构系统。通过对速度通道图进行树状图分析，并在位置-位置-速度空间中进行链接，我们识别出16个近似径向分布的流状结构，其投影轨迹汇聚于一个共同的中心区域。外流的动能比大多数已知爆炸性外流至少低一个数量级，而其质量夹带率和动量率相对于典型原恒星外流较高，这表明I16119可能是一个低能量爆炸性外流候选体。致密气体和光致离解区示踪物揭示了与8 $\mu$m发射相关的壳层结构，表明H II区的反馈可能影响流状结构的形态。1.3 mm连续谱在一条碎裂的丝状结构中分辨出27个致密核。它们的间距与热金斯或柱状碎裂一致，而collect-and-collapse情景则不被支持。致密核还显示出质量分层的证据，最质量的核集中在推断的爆炸中心附近。我们认为I16119是一个合理的低能量爆炸性外流候选体，可能是由中心集中大质量核之间的动力学相互作用触发的。然而，复杂的速度结构和来自单个核驱动外流的可能污染阻碍了明确分类。需要更高灵敏度、更高角分辨率的观测来确认外流的性质。
英文摘要：
We present a multiwavelength study of the massive star formation region IRAS 16119-5048 (I16119) using ALMA ATOMS Band 3 and QUARKS Band 6 observations, complemented by archival ATCA radio continuum and Spitzer mid-infrared data. The CO (2-1) emission reveals a system of high-velocity streamer-like structures around the central region. Using dendrogram analysis of velocity-channel maps followed by linking in position-position-velocity space, we identify 16 approximately radially distributed streamers whose projected trajectories converge toward a common central region. The kinetic energy of the outflows is at least an order of magnitude lower than those of most known explosive outflows, while their mass entrainment and momentum rates are high compared with typical protostellar outflows, suggesting that I16119 may represent a low-energy explosive outflow candidate. Dense-gas and photodissociation-region tracers reveal shell-like structures associated with the 8 $μ$m emission, indicating that feedback from the H II region may influence the streamer morphology. The 1.3 mm continuum resolves 27 dense cores along a fragmented filamentary structure. Their separations are consistent with thermal Jeans or cylindrical fragmentation, while the collect-and-collapse scenario is unsupported. The dense cores also show evidence of mass segregation, with the most massive cores concentrated near the inferred explosive centre. We suggest that I16119 is a plausible low-energy explosive outflow candidate, possibly triggered by dynamical interactions among centrally concentrated massive cores. However, the complex velocity structure and possible contamination from individual core-driven outflows prevent a definitive classification. More sensitive, higher angular-resolution observations are required to confirm the nature of the outflow.
