CAREER: Giant Planets in Dusty Disks

尘埃颗粒对生长中的行星及其宿主盘的影响远远超出了为行星核心提供种子材料的范围。颗粒决定了盘的垂直结构、盘的演化速度和主导行星的形成机制。 PI 和她的团队将把尘埃沉降和颗粒生长纳入一个随时间演化的原恒星盘模型，并使用该模型来测试与尘埃对行星形成的影响有关的三个假设。首先，通过降低原恒星盘的尺度高度，颗粒生长和沉降可能会限制通过核心吸积到木星以下质量的行星形成。其次，晶粒生长和沉降可能会通过增加圆盘对其自身辐射的透明度而引发先前稳定的圆盘中的重力不稳定。第三，在中红外区域，橄榄石颗粒的不透明度随着铁丰度的增加而增加，随着镁丰度的增加而减少，其中圆盘辐射由粘性湍流产生的热量。主要的行星形成机制可能取决于星盘材料的 [Mg/Fe] 比例。 PI 将通过启动新轨道计划，将她对行星形成的研究转化为大学一年级学生的教育丰富活动，该计划每年有 20 名学生组成一个以行星科学为中心的学习社区。新轨道计划旨在帮助即将入学的学生对自己从事科学事业的能力充满信心。新轨道项目的学生将与 PI 一起参加每周一次的研讨会，并每学期一起参加天文学和地质学课程，以满足他们的一般科学要求，同时学习行星科学的基础知识。新轨道计划的顶峰将是每年一次前往麦克唐纳天文台的实地考察，了解 82 英寸望远镜历史上和正在进行的行星研究。

The influence of dust grains on growing planets and their host disks extends far beyond providing seed material for planet cores. Grains determine the disk vertical structure, disk evolution rate, and dominant planet formation mechanism. The PI and her team will incorporate dust settling and grain growth into a time-evolving protostellar disk model and use the model to test three hypotheses relating to the influence of dust on planet formation. First, grain growth and settling, by lowering the scale height of the protostellar disk, may restrict planets forming by core accretion to sub-Jupiter masses. Second, grain growth and settling may trigger gravitational instability in a disk that was previously stable by increasing the disk's transparency to its own radiation. Third, olivine grain opacity increases with iron abundance and decreases with magnesium abundance in the mid-infrared, where the disk radiates heat generated by viscous turbulence. The dominant planet formation mechanism may depend on the [Mg/Fe] ratio of the star-disk material.The PI will translate her research on planet formation into educational enrichment for first-year college students by starting the New Orbits program, a cohort of 20 students each year who will form a learning community centered on planetary science. The New Orbits program is designed to help incoming students feel confident in their ability to pursue a career in science. New Orbits students will attend a weekly seminar with the PI and take astronomy and geology classes together each semester to fulfill their general science requirement while learning the basics of planetary science. The capstone of the New Orbits program will be a yearly field trip to McDonald Observatory to learn about historic and ongoing planetary research at the 82 inch telescope.