发表机构
Leiden University; Max-Planck-Institut für Extraterrestrische Physik; University of Hawai’i at Manoa; University of Cambridge; Center for Astrophysics, Harvard & Smithsonian; Max Planck Institute for Astronomy; INAF-Osservatorio Astronomico di Capodimonte; The University of Toledo（莱顿大学; 马克斯·普朗克地外物理研究所; 夏威夷大学马诺阿分校; 剑桥大学; 哈佛与史密森尼天体物理中心; 马克斯·普朗克天文学研究所; 意大利国家天体物理研究所卡波迪蒙特天文台; 托莱多大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用JWST NIRSpec IFU观测绘制原恒星包层中多种冰的分布，发现冰分布与温度结构相关，并揭示L1527和IRAS 20126+4104中冰的分离、增强及升华等局部特征。
AI 中文摘要
行星及其大气的组成在很大程度上取决于行星的形成环境。这一环境在原恒星仍在形成时的早期阶段就已预先确定。因此，描绘原恒星包层的结构对于理解化学过程如何与恒星形成区中发生的物理过程相关联至关重要。我们利用JWST NIRSpec IFU观测，提取IFU中每个像素的光谱，并绘制$^{13}$CO$_2$、$^{12}$CO$_2$、CO、OCN$^-$和H$_2$O冰的分布图。$^{13}$CO$_2$冰特征作为已知的热示踪剂，也被用于识别冰经历热过程的高温区域。研究结果表明，L1527和IRAS 20126+4104中冰的分布并不均匀，两个包层都显示出局部温度区域和子结构。在L1527中，在原恒星附近温暖的中央盘区域观测到CO$_2$冰的分离以及相对于CO$_2$的OCN$^-$增强。在IRAS 20126+4104中，温暖温度区域主要朝向西北外流中的激波区域，那里致密物质与进动喷流相互作用，以及靠近中央源的位置。CO$_2$冰在这些位置发生分离，我们观测到CO冰的升华。此外，在包层中的几个位置探测到结晶态H$_2$O冰。在低质量和高质量原恒星中，研究结果表明冰的分布及其结构与包层的温度结构相关联。IRAS 20126的包层显示出更复杂的结构，相互作用的物质导致局部高温区域和容纳较冷冰的更致密区域。相比之下，L1527似乎是一个更有结构的系统，加热的温暖冰主要朝向中央盘区域观测到。
英文摘要
The composition of planets and their atmospheres is largely determined by the formation environment of the planet. This environment is pre-determined during early stages when the protostar is still forming. Charting the structure of protostellar envelopes is therefore crucial for understanding how the chemistry is linked to the physical processes occurring in stellar nurseries. We use JWST NIRSpec IFU observations to extract spectra at every pixel in the IFU and map the distribution of $^{13}$CO$_2$,$^{12}$CO$_2$, CO, OCN$^-$ and H$_2$O ice. The 13CO2 ice feature, a known thermal tracer, is also used to identify high-temperature regions where the ices are thermally processed. The findings show that the distribution of ices in both L1527 and IRAS 20126+4104 is not uniform, with both envelopes showing localized temperature zones and substructures. In L1527, CO$_2$ ice segregation and OCN$^-$ enhancement with respect to CO$_2$ are observed in the warm central disk region close to the protostar. In IRAS 20126+4104, the warm temperature zones are observed mostly towards the shocked region in the NW outflow where dense material is interacting with the precessing jet as well as close to the central source. The CO$_2$ ice is segregated at these locations and we observe sublimation of CO ice. In addition, crystalline H$_2$O ice is detected at a few locations in the envelope. In both low mass and high mass protostar the findings indicate that the distribution of ices and their structure are linked to the temperature structure of the envelopes. The envelope of IRAS 20126 shows a more complex structure, where interacting material results in localized regions of high temperatures and denser regions that harbor cooler ices. L1527 in contrast appears to be a more structured system with heated warm ices observed mostly towards the central disk regions.
