阿雷西博甲醇脉泽银道巡天IV：精确的天体测量和源形态
The Arecibo Methanol Maser Galactic Plane Survey-IV: Accurate Astrometry and Source Morphologies
摘要：
我们提出了精确的绝对天体测量的6.7 GHz甲醇脉泽在阿雷西博甲醇脉泽银河系平面调查使用MERLIN和扩展的甚大阵列（EVLA）检测。我们估计绝对天体测量的精度优于15和80毫角秒的MERLIN和EVLA观测分别。我们还导出了强于~ 1 Jy的脉泽辐射分布的形态。显示脉泽发射的区域沿长轴的空间范围中值为~ 775 AU。我们发现大多数的甲醇脉泽形态是复杂的一些来源，以前确定有规则的形态，实际上是嵌入在较大的结构。这表明有些脉泽斑点没有致密的核心，这导致它们在高角分辨率观测中被分辨。这也使人怀疑的解释的起源，甲醇脉泽排放完全基于源形态。我们还研究了甲醇脉泽与中红外辐射之间的关系，发现甲醇脉泽与24微米点源之间有非常密切的对应关系。这进一步增加了可信度的理论模型，预测甲醇脉泽被抽走温暖的尘埃排放，并坚定地加强了发现，第二类甲醇脉泽是明确的示踪剂嵌入的高质量原恒星。
英文摘要：
We present accurate absolute astrometry of 6.7 GHz methanol masers detected in the Arecibo Methanol Maser Galactic Plane Survey using MERLIN and the Expanded Very Large Array (EVLA). We estimate the absolute astrometry to be accurate to better than 15 and 80 milliarcseconds for the MERLIN and EVLA observations respectively. We also derive the morphologies of the maser emission distributions for sources stronger than ~ 1 Jy. The median spatial extent along the major axis of the regions showing maser emission is ~ 775 AU. We find a majority of methanol maser morphologies to be complex with some sources previously determined to have regular morphologies in fact being embedded within larger structures. This suggests that some maser spots do not have a compact core, which leads them being resolved in high angular resolution observations. This also casts doubt on interpretations of the origin of methanol maser emission solely based on source morphologies. We also investigate the association of methanol masers with mid-infrared emission and find very close correspondence between methanol masers and 24 micron point sources. This adds further credence to theoretical models that predict methanol masers to be pumped by warm dust emission and firmly reinforces the finding that Class II methanol masers are unambiguous tracers of embedded high-mass protostars.
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。
