对NGC 1333和IC 348中年轻恒星天体的X射线和射电同时观测
Simultaneous X-ray and radio observations of Young Stellar Objects in NGC 1333 and IC 348
摘要：
年轻的恒星天体（YSO），特别是原恒星，被认为表现出各种高能过程。在X射线和厘米射电波长范围内的观测被认为限制了其中的一些过程，例如，日冕型磁活动在活跃恒星中，射电和X射线光度之间有一个众所周知的经验相关性，即所谓的盖德尔-本茨关系。先前的证据是否YSO与这种关系相容，对于最早的进化阶段仍然没有定论。主要的困难是，由于这些来源的极端可变性，同时观测是必不可少的。到目前为止，在X射线和射电范围内，只有少数的YSO和少数的原恒星被同时观测到。为了扩大样本，我们已经获得了两个年轻的星团，NGC 1333和IC 348的原恒星丰富的观测。虽然这些地区的绝对灵敏度比附近的集群，如CrA低，我们发现，即使在深连续观测进行的NRAO超大型阵列，在这些集群中的原恒星的无线电探测分数远低于X射线检测分数。在这两个波段都检测到很少的YSO，我们发现YSO之间的无线电和X射线种群在很大程度上是不同的。我们结合这些新的结果与以前同时钱德拉和VLA观测恒星形成的地区，发现在两个波段的检测YSO似乎是向更高的无线电光度为给定的X射线光度相比，盖德尔-奔驰关系，虽然即使在这个敏感的数据集大多数来源是太弱的无线电探测提供信息的发射过程。扩展甚大天线阵的灵敏度大大提高，将更好地普查YSO无线电人口，并更好地限制发射机制。
英文摘要：
Young Stellar Objects (YSOs) and in particular protostars are known to show a variety of high-energy processes. Observations in the X-ray and centimetric radio wavelength ranges are thought to constrain some of these processes, e.g., coronal-type magnetic activity. There is a well-known empirical correlation of radio and X-ray luminosities in active stars, the so-called Guedel-Benz relation. Previous evidence whether YSOs are compatible with this relation remains inconclusive for the earliest evolutionary stages. The main difficulty is that due to the extreme variability of these sources, simultaneous observations are essential. Until now, only few YSOs and only a handful of protostars have been observed simultaneously in the X-ray and radio range. To expand the sample, we have obtained such observations of two young clusters rich in protostars, NGC 1333 and IC 348. While the absolute sensitivity is lower for these regions than for more nearby clusters like CrA, we find that even in deep continuum observations carried out with the NRAO Very Large Array, the radio detection fraction for protostars in these clusters is much lower than the X-ray detection fraction. Very few YSOs are detected in both bands, and we find the radio and X-ray populations among YSOs to be largely distinct. We combine these new results with previous simultaneous Chandra and VLA observations of star-forming regions and find that YSOs with detections in both bands appear to be offset toward higher radio luminosities for given X-ray luminosities when compared to the Guedel-Benz relation, although even in this sensitive dataset most sources are too weak for the radio detections to provide information on the emission processes. The considerably improved sensitivity of the Expanded Very Large Array will provide a better census of the YSO radio population as well as better constraints on the emission mechanisms.
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。
