IRAS05506 +2414中的高速星际子弹：一颗非常年轻的原恒星
High-Velocity Interstellar Bullets in IRAS05506+2414: A Very Young Protostar
摘要：
我们偶然发现了一个神秘的外流源，IRAS 05506+2414（以下简称IRAS 05506），作为行星前星云（PPN）多波长巡天的一部分。HST的光学和近红外图像显示了一个明亮紧凑的中心源，具有喷流状的延伸，以及一个由高速（径向速度高达350公里/秒）细长节组成的扇形喷雾，这些结构可能类似于猎户座星云中的近红外“子弹”。在2.6毫米的干涉观测表明存在一个高速CO流出和连续源也有微弱的扩展，这两者都与光学喷流结构。IRAS 05506很可能不是PPN。我们发现扩展的NH3（1，1）发射朝向IRAS 05506;这些数据与远红外发射，H2O和OH脉泽，CO和CS J=2-1发射的组合存在一起，强烈主张与IRAS 05506相关的致密，多尘的恒星形成核心。IRAS 05506可能是一颗中等质量或大质量的原恒星，其流出的时间尺度很短（200年），表明它非常年轻。如果IRAS 05506是一颗大质量恒星，那么缺乏射电连续谱和我们从光谱中发现的晚G -早K光谱类型意味着在这个物体中，我们正在见证它生命的最早阶段，而它的温度仍然太低，无法提供足够的紫外线通量进行电离。
英文摘要：
We have made a serendipitous discovery of an enigmatic outflow source, IRAS 05506+2414 (hereafter IRAS 05506), as part of a multi-wavelength survey of pre-planetary nebulae (PPNs). The HST optical and near-infrared images show a bright compact central source with a jet-like extension, and a fan-like spray of high-velocity (with radial velocities upto 350 kms/s) elongated knots which appear to emanate from it. These structures are possibly analogous to the near-IR "bullets" seen in the Orion nebula. Interferometric observations at 2.6 mm show the presence of a high-velocity CO outflow and a continuum source also with a faint extension, both of which are aligned with the optical jet structure. IRAS 05506 is most likely not a PPN. We find extended NH3 (1,1) emission towards IRAS 05506; these data together with the combined presence of far-IR emission, H2O and OH masers, and CO and CS J=2-1 emission, strongly argue for a dense, dusty star-forming core associated with IRAS 05506. IRAS 05506 is probably an intermediate-mass or massive protostar, and the very short time-scale (200 yr) of its outflows indicates that it is very young. If IRAS 05506 is a massive star, then the lack of radio continuum and the late G -- early K spectral type we find from our optical spectra implies that in this object we are witnessing the earliest stages of its life, while its temperature is still too low to provide sufficient UV flux for ionisation.
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。
