AI 中文总结
本研究借助ALMA数据编目0级原恒星L1527 IRS周围盘与包层的化学组成，探测到39种分子，明确了盘与包层的化学差异，为研究行星形成物质的化学演化提供了基础。
AI 中文摘要
行星形成始于仍嵌入在诞生包层中的原行星盘。本研究对0级原恒星L1527 IRS周围的盘和包层（<3500天文单位）的化学组成进行了详尽的编目。利用所有公开的ALMA（阿塔卡马大型毫米/亚毫米波阵列）数据，我们报告了对39种分子（包括同位素体）的探测结果，其中22种为不同的分子种类，28种是在ALMA观测中首次在L1527方向被报道的。CH₃OH是唯一被探测到的复杂有机分子，而烃类CH₃CCH是被探测到的最大分子。总体而言，只有少数项目具备足够的灵敏度，能基于运动学明确探测到源自盘的发射。含氮分子主要在更延展的尺度上被探测到，而烃类则呈现出大致沿东南外流腔壁分布的独特尾状结构，这可能是由于东外流瓣区域存在更强的紫外场。L1527 IRS原恒星系统并不富含含硫分子，仅观测到CS和SO有强发射。总体而言，包层似乎以富碳化学为主，而在盘中则似乎转变为富氧化学。我们计算了所有被探测物种的柱密度，为量化年轻盘之间的化学多样性以及行星形成物质的化学演化提供了起点。
英文摘要
Planet formation starts in disks that are still embedded within their natal envelopes. Here, we compile an extensive inventory of the chemical composition of the disk and envelope ($<$ 3500 au) around the Class 0 protostar L1527 IRS. Using all publicly available ALMA (Atacama Large Millimeter/submillimeter Array) data, we report the detection of 40 molecules, including isotopologues. Of these, 23 are different molecular species and 29 are reported here for the first time toward L1527 in ALMA observations. CH$_3$OH is the only complex organic molecule detected, while the hydrocarbon CH$_3$CCH is the largest molecule detected. Overall, only a few programs are sensitive enough to detect emission unambiguously originating from the disk based on the kinematics. Nitrogen-bearing molecules are predominantly detected on more extended scales, while hydrocarbons show a distinct tail roughly along the southeastern outflow cavity wall, probably due to a stronger UV field in the eastern outflow lobe. The L1527 IRS protostellar system is not rich in sulfur-bearing molecules, with only strong emission observed for CS and SO. Overall, the envelope appears dominated by a carbon-rich chemistry, which seems to transition into an oxygen-rich chemistry in the disk. We calculate column densities of all detected species, providing a starting point to quantify the chemical diversity among young disks and the chemical evolution of the planet-forming material.
CommentsAccepted by Frontiers in Astronomy and Space Sciences. Special Issue: Birthplaces of Planets in Their Earliest Stages: Towards Characterization of Young Protostellar Disks
