A Circumplanetary Disk around PDS70c
A Circumplanetary Disk around PDS70c
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DOI：
10.3847/2041-8213/ac0f83
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发表时间：
2021-07-01
影响因子：
7.9
通讯作者：
Zurlo, Alice
中科院分区：
文献类型：
--
作者：
Benisty, Myriam;Bae, Jaehan;Zurlo, Alice
PDS 70是一个独特的系统，在该系统中，通过在红外波长上直接成像，在其圆盘的尘埃耗尽的空腔中发现了两颗原行星，PDS 70b和pds 70c，分别类似于22Au和34Au。随后对Hα线上行星的探测表明，它们仍在通过环行星盘吸积物质。在这封信中，我们提供了新的阿塔卡马大毫米/亚毫米阵列(ALMA)观测，在855微米的高角度分辨率(类似于20马斯，2.3Au)的尘埃连续发射，目的是解决绕行星盘和限制其尘埃质量。我们的观测证实了与PdS 70c共存的致密辐射源的存在，该辐射源在空间上与恒星周盘分开，半径不到1.2Au，这个值接近希尔半径的三分之一处的周行星盘的预期截断半径。PdS 70c附近的发射峰强度类似于86+/-16微米Jy束(-1)，相当于约0.031米(圆形+)或类似0.007米(圆形+)的尘埃质量，假设它们分别只由1微米或1毫米大小的颗粒组成。我们还在PdS 70b附近的空腔内探测到了扩展的、低表面亮度的连续发射。我们在恒星的18au范围内观察到一个光学薄的内盘，其发射可能是由外盘通过b和c轨道传输的小微米尺寸的颗粒造成的。此外，我们还发现外盘解析成一个窄而明亮的环，具有微弱的内肩。
PDS 70 is a unique system in which two protoplanets, PDS 70 b and c, have been discovered within the dust-depleted cavity of their disk, at similar to 22 and 34 au, respectively, by direct imaging at infrared wavelengths. Subsequent detection of the planets in the H alpha line indicates that they are still accreting material through circumplanetary disks. In this Letter, we present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the dust continuum emission at 855 mu m at high angular resolution (similar to 20 mas, 2.3 au) that aim to resolve the circumplanetary disks and constrain their dust masses. Our observations confirm the presence of a compact source of emission co-located with PDS 70 c, spatially separated from the circumstellar disk and less extended than similar to 1.2 au in radius, a value close to the expected truncation radius of the circumplanetary disk at a third of the Hill radius. The emission around PDS 70 c has a peak intensity of similar to 86 +/- 16 mu Jy beam(-1), which corresponds to a dust mass of similar to 0.031 M (circle plus) or similar to 0.007 M (circle plus), assuming that it is only constituted of 1 mu m or 1 mm sized grains, respectively. We also detect extended, low surface brightness continuum emission within the cavity near PDS 70 b. We observe an optically thin inner disk within 18 au of the star with an emission that could result from small micron-sized grains transported from the outer disk through the orbits of b and c. In addition, we find that the outer disk resolves into a narrow and bright ring with a faint inner shoulder.