论文标题
部分可观测时空混沌系统的无模型预测
Unusual Abundances from Planetary System Material Polluting the White Dwarf G238-44
论文作者
论文摘要
用保险丝，Keck/Hires，HST/COS和HST/STIS获得的氢为氢气大气的紫外线和光谱白色矮星G238-44显示出比氦气重的十个元素：C，N，N，O，O，MG，MG，Al，Al，Si，si，p，s，s，ca，ca，ca和fe。 G238-44只是第三个白色矮人，在其大气中从污染的行星系统材料中检测到氮。在24年内，凯克/雇用数据在11个晚上获取的数据没有证据表明测得的吸收线等效宽度的变化，这表明与室内储层中的稳定且连续积聚。从测得的丰度和对其他元素的限制，我们发现了存在金属铁的异常丰度模式和证据。如果污染来自单亲身体，则在太阳系中将没有已知的对应物。如果我们允许两个不同的母体，那么我们可以用富含铁的汞样材料和一个冰冷的kuiper带对象的类似物的质量比为1.7：1的冰冷的kuiper带对物体的类似物来重现观察到的丰度。这种构图不同的物体将为超球星系中的岩石和冰冷的身体提供化学证据，并将表明行星系统非常扰动，以至于G238-44能够在其$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ <$ cooling的年龄中。
Ultraviolet and optical spectra of the hydrogen-dominated atmosphere white dwarf star G238-44 obtained with FUSE, Keck/HIRES, HST/COS, and HST/STIS reveal ten elements heavier than helium: C, N, O, Mg, Al, Si, P, S, Ca, and Fe. G238-44 is only the third white dwarf with nitrogen detected in its atmosphere from polluting planetary system material. Keck/HIRES data taken on eleven nights over 24 years show no evidence for variation in the equivalent width of measured absorption lines, suggesting stable and continuous accretion from a circumstellar reservoir. From measured abundances and limits on other elements we find an anomalous abundance pattern and evidence for the presence of metallic iron. If the pollution is from a single parent body, then it would have no known counterpart within the solar system. If we allow for two distinct parent bodies, then we can reproduce the observed abundances with a mix of iron-rich Mercury-like material and an analog of an icy Kuiper Belt object with a respective mass ratio of 1.7:1. Such compositionally disparate objects would provide chemical evidence for both rocky and icy bodies in an exoplanetary system and would be indicative of a planetary system so strongly perturbed that G238-44 is able to capture both asteroid- and Kuiper Belt-analog bodies near-simultaneously within its $<$100 Myr cooling age.
