Near-infrared image of the debris disk around HD 15115

作者：Sai Shoko^*; Itoh Yoichi; Fukagawa Misato; Shibai Hiroshi; Sumi Takahiro

来源：Publications of the Astronomical Society of Japan, 2015, 67(2): 20.

DOI：10.1093/pasj/psu152

• circumstellar matter
• planet-disk interactions
• stars: individual (HD 15115)
• techniques: high angular resolution

We present a Subaru/Infrared Camera and Spectrograph H-band image of the edge-on debris disk around the F2V star HD15115. We detected the debris disk, which has a bow shape and an asymmetric surface brightness, at a projected separation of 1 ''-3 '' (similar to 50-150 au). The disk surface brightness is similar to 0.5-1.5 mag brighter on the western side than on the eastern side. We use an inclined annulus disk model to probe the disk geometry. The model fitting suggests that the disk has an inner hole with a radius of 86 au and an eccentricity of 0.06. The disk model also indicates that the amount of dust on the western side is 2.2 times larger than that on the eastern side. A several Jupiter-mass planet may exist at greater than or similar to 45 au and capture grains at the Lagrangian points to open the eccentric gap. This scenario can explain both the eccentric gap and the difference in the amount of dust. In case of the stellar age of several 100 Myr, a dramatic planetesimal collision possibly causes the dust to increase in the western side. Interstellar medium interaction is also considered as a possible explanation of the asymmetric surface brightness, however, it hardly affects large grains in the vicinity of the inner hole.

• 出版日期2015-4