An ALMA Search for High-albedo Objects Among the Midsized Jupiter Trojan Population
An ALMA Search for High-albedo Objects Among the Midsized Jupiter Trojan Population
复制标题
DOI：
10.3847/1538-3881/ac559e
复制
发表时间：
2022-02
期刊：
影响因子：
--
通讯作者：
Anna M. Simpson;M. Brown;M. Schemel;B. Butler
中科院分区：
文献类型：
--
作者：
Anna M. Simpson;M. Brown;M. Schemel;B. Butler
我们使用阿塔卡马大毫米阵列对一个中型(直径15-40公里)木星特洛伊小行星样本的870μm热发射进行测量，以寻找该种群中的高反照率天体。我们使用一个热模型计算了每个天体的直径和反照率，该模型还结合了同期的兹维基瞬变设施光度法，以准确地测量ALMA观测时的绝对星等。我们发现，虽然许多反照率比WISE报告的要低，但几个小特洛伊木马的反照率很高，这是由ALMA和WISE独立测量的。这些高反照率物体的数量与最近经历大规模撞击的物体数量的预期大致一致，这表明新装的木星特洛伊木马的内部可能含有冰等高反照率物质。
We use Atacama Large Millimeter Array (ALMA) measurements of 870 μm thermal emission from a sample of midsized (15–40 km diameter) Jupiter Trojan asteroids to search for high-albedo objects in this population. We calculate the diameters and albedos of each object using a thermal model which also incorporates contemporaneous Zwicky Transient Facility photometry to accurately measure the absolute magnitude at the time of the ALMA observation. We find that while many albedos are lower than reported from WISE, several small Trojans have high albedos independently measured both from ALMA and from WISE. The number of these high-albedo objects is approximately consistent with expectations of the number of objects that recently have undergone large-scale impacts, suggesting that the interiors of freshly-crated Jupiter Trojans could contain high-albedo materials such as ices.