Collaborative Research: RUI: Protostellar jets across the mass spectrum

众所周知，像太阳这样的恒星是由星际空间中的分子气体云形成的。这些云在重力的影响下逐渐崩塌，密度变得更大，变得更小。当这种情况发生时，云的任何初始旋转都会被放大，就像滑冰运动员拉起胳膊来加速旋转一样。这是因为一种被称为角动量守恒的现象。然而，如果形成恒星的物质完全守恒其角动量，即自旋度，那么当它变得像恒星一样小的时候，它的自转速度将如此之快，以至于它将不再稳定，并被抛出。像我们的太阳这样的恒星是如何形成的，需要相当低的自转速度，这个谜题的答案被认为与这项研究的主题--“原恒星喷流”现象有关。当年轻恒星形成时，几乎总是可以看到快速流动的气体被准直成两个喷流，也就是说，当它们是“原恒星”的时候。这些喷流被认为是从环绕正在成长的恒星周围的旋转气体圆盘发射的，因为磁场的作用使旋转的气体盘绕在圆盘上。这些磁场被认为变得足够强大，可以从圆盘中发射出一些气体，从留下的物质中带走角动量，然后最终稳定在恒星上。这些圆盘的残余物可能会变成行星系统，就像我们太阳系的行星一样。研究人员试图通过更好地了解原恒星喷流是如何发射的，来了解恒星和行星是如何诞生的。研究人员将对原恒星喷流进行计算机模拟，以了解它们的性质，包括从我们的太阳这样质量相对较低的恒星，到我们银河系中也存在的质量大得多的恒星。这些模拟的结果将与射电望远镜对原恒星喷流的观测结果进行比较，以检验理论模拟。更广泛的影响计划将研究与教学和公共宣传活动相结合。在维尔京群岛大学(UVI)，每年将有三名本科生参与研究项目，为代表性不足的群体提供STEM职业发展的重要机会。这项建议将有助于加强弗吉尼亚大学这个新的研究小组与弗吉尼亚大学(UVA)之间的合作。该合作计划包括UVI和UVA之间的学生交流，扩大了两个组织的视野。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Stars, like our Sun, are known to form from clouds of molecular gas in interstellar space. These clouds gradually collapse under the influence of gravity, becoming denser and smaller. As this happens, any initial spin of the cloud is amplified, much like when an ice skater pulls their arms in to spin faster. This occurs because of a phenomenon known as the conservation of angular momentum. However, if material that was to form a star fully conserved its angular momentum, i.e., its degree of spin, then by the time it became as small as a star it would be spinning so quickly that it would no longer be stable and would be flung apart. The answer to this riddle of how stars like our Sun have been able to form, requiring quite low rates of spin, is thought to be related to the phenomenon of "Protostellar Jets", which is the subject of this research. Fast flowing gas, collimated into a pair of jets, is almost always seen when young stars are forming, i.e., when they are "protostars". These jets are thought to be launched from a spinning gas disk that surrounds the growing star because of the action of magnetic fields threading the disk that become wound up by the swirling gas. These magnetic fields are thought to become powerful enough to launch some of the gas from the disk, which carries away angular momentum from material left behind that can then eventually settle on to the star. The remnants of such disks may become systems of planets, like those of our solar system. The investigators seek to understand how stars and planets are born by better understanding how protostellar jets are launched. The investigators will perform computer simulations of protostellar jets understand their properties, including from relatively low-mass stars like our Sun, to much more massive stars that also exist in our Galaxy. The results of these simulations will be compared to observations of protostellar jets made by radio telescopes to test the theoretical simulations.The broader impact plan integrates research with teaching and public outreach activities. At the University of the Virgin Islands (UVI) three undergraduates will share in the research projects each year, providing important opportunities for STEM career development for underrepresented groups. This proposal will help strengthen a collaboration between this new research group at UVI and the University of Virginia (UVA). The collaboration plan includes student exchanges between UVI and UVA, expanding the horizons of both groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.