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arXiv 1008.0865astro-ph.SR
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HD191089碎片盘的分辨成像

Resolved Imaging of the HD191089 Debris Disc

Laura J. Churcher, Mark C. Wyatt, Rachel Smith

摘要:

在有1200万年历史的如画贝塔移动星群(Beta Picture Moving Group,BPMG)中,有三分之二的F星成员在中红外线上显示出显著的过量辐射,这是在原行星盘预期分散之后的几百万年。行星形成的理论模型表明,中红外辐射的这个峰值可能是由于盘中形成了冥王星大小的天体,这些天体点燃了碰撞级联,增加了小尘埃的产生。在这里,我们提出了解决中红外成像的磁盘HD 191089(F5 V的BPMG),并考虑其影响的状态行星形成在这个系统中。在Gemini South上使用T-ReCS在18.3微米处观察到HD 191089,并将图像与圆盘模型进行比较,以限制尘埃的径向分布。在18.3微米处观察到的发射被示出为在80度的位置角处显著地延伸超过PSF。这是第一次在HD 191089附近解决粉尘排放问题。模拟显示,辐射来自28-90天文单位的尘埃带,从边缘倾斜35度,从盘的内部28天文单位发出的辐射很少,表明存在内部空腔。内边缘的陡坡更符合行星的截断,而不是持续的搅动。盘两侧的亮度不对称性F(W)/F(E)=0.80+/-0.12(1.8 sigma)可能是系统中偏心轨道上的大质量天体扰动的证据。

英文摘要:

Two thirds of the F star members of the 12 Myr old Beta Pictoris Moving Group (BPMG) show significant excess emission in the mid-infrared, several million years after the expected dispersal of the protoplanetary disc. Theoretical models of planet formation suggest that this peak in the mid-infrared emission could be due to the formation of Pluto-sized bodies in the disc, which ignite the collisional cascade and enhance the production of small dust. Here we present resolved mid-infrared imaging of the disc of HD191089 (F5V in the BPMG) and consider its implications for the state of planet formation in this system. HD191089 was observed at 18.3 microns using T-ReCS on Gemini South and the images were compared to models of the disc to constrain the radial distribution of the dust. The emission observed at 18.3 microns is shown to be significantly extended beyond the PSF at a position angle of 80 degrees. This is the first time dust emission has been resolved around HD191089. Modelling indicates that the emission arises from a dust belt from 28-90 AU, inclined at 35 degrees from edge on with very little emission from the inner 28AU of the disc, indicating the presence of an inner cavity. The steep slope of the inner edge is more consistent with truncation by a planet than with ongoing stirring. A tentative brightness asymmetry F(W)/F(E)=0.80+/-0.12 (1.8 sigma) between the two sides of the disc could be evidence for perturbations from a massive body on an eccentric orbit in the system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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