类原太阳盘III中的引力不稳定性：分子线探测和灵敏度
Gravitational instabilities in a protosolar-like disc III: molecular line detection and sensitivities
摘要：
在形成时，原行星盘可能包含与其宿主原恒星相当的质量。因此，引力不稳定性（GI）预计将在盘演化的早期阶段发挥关键作用。然而，由于这些年轻的物体被大量嵌入，地理标志的确认仍然难以捉摸。因此，我们使用辐射转移程序LIME来产生一个$0.17\,\mathrm{M}_{\odot}$自引力类原太阳盘的线图像。我们注意到使用LIME的局限性，并探索改进默认网格的方法。我们合成无噪声观测，以确定所需的灵敏度来检测螺旋通量，并发现线通量分布并不一定相关的丰度密度分布，因此执行辐射转移计算是必要的。此外，由于GI加热的中平面和高消光，在吸收中看到螺旋特征，这可能指示GI活动。如果使用一个小的光束尺寸和适当的分子线，然后空间分辨螺旋在一个原太阳像光盘应该是可能的ALMA源时间为30小时。光谱分辨非轴对称结构只需要十分之一的时间为一个合理的噪音水平，但归因于这种结构GI引起的活动将是试探性的。最后，我们发现，识别手指状功能PV图的近边缘上的光盘，这是一个直接的指标的螺旋，是可行的源时间为19小时，因此可能提供了最有前途的手段，确认GI驱动的螺旋结构在年轻的，嵌入式原行星盘。
英文摘要：
At the time of formation, protoplanetary discs likely contain a comparable mass to their host protostars. As a result, gravitational instabilities (GIs) are expected to play a pivotal role in the early phases of disc evolution. However, as these young objects are heavily embedded, confirmation of GIs has remained elusive. Therefore, we use the radiative transfer code LIME to produce line images of a $0.17\,\mathrm{M}_{\odot}$ self-gravitating protosolar-like disc. We note the limitations of using LIME and explore methods to improve upon the default gridding. We synthesise noiseless observations to determine the sensitivities required to detect the spiral flux, and find that the line flux distribution does not necessarily correlate to the abundance density distribution; hence performing radiative transfer calculations is imperative. Moreover, the spiral features are seen in absorption, due to the GI-heated midplane and high extinction, which could be indicative of GI activity. If a small beamsize and appropriate molecular line are used then spatially resolving spirals in a protosolar-like disc should be possible with ALMA for an on-source time of 30 hr. Spectrally resolving non-axisymmetric structure takes only a tenth as long for a reasonable noise level, but attributing this structure to GI-induced activity would be tentative. Finally, we find that identifying finger-like features in PV diagrams of nearly edge-on discs, which are a direct indicator of spirals, is feasible with an on-source time of 19 hr, and hence likely offers the most promising means of confirming GI-driven spiral structure in young, embedded protoplanetary discs.
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。
