Why are there so few hot Jupiters
Why are there so few hot Jupiters
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为什么热木星这么少
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. F. Hogg
中科院分区：
文献类型：
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作者：
W. K. M. Rice;P. Armitage;D. F. Hogg
我们使用数值模拟来模拟小半径大质量行星的迁移，并将结果与已知的‘热木星’(半长轴为0.5MJ的太阳系外行星)的性质进行比较，小半径的任何‘堆积’的证据都很弱(统计上没有意义)，尽管与更远的参考样本相比，在大质量行星中热木星的质量函数是不足的，但小样本大小排除了确定的结论。我们认为，这些性质与进入恒星附近的磁层空穴之后的圆盘迁移是一致的。进入空腔会导致迁移速度减慢，并伴随着轨道偏心率的增加。对于质量超过1木星的行星，我们发现偏心率增长的时间尺度为几个×105年，这表明这些行星可能经常被迅速摧毁。对于质量较大的行星，偏心率增长似乎更快，这可能解释了行星质量函数在小半径处的变化，也可能预示着质量较低的行星会堆积在一起，其样本仍不完整。
We use numerical simulations to model the migration of massive planets at small radii and compare the results with the known properties of ’hot Jupiters’ (extrasolar planets with semi-major axes a 0.5MJ, the evidence for any ‘pile-up’ at small radii is weak (statistically insignificant), and although the mass function of hot Jupiters is deficient in high mass planets as compared to a reference sample located further out, the small sample size precludes definitive conclusions. We suggest that these properties are consistent with disc migration followed by entry into a magnetospheric cavity close to the star. Entry into the cavity results in a slowing of migration, accompanied by a growth in orbital eccentricity. For planet masses in excess of 1 Jupiter mass we find eccentricity growth timescales of a few×10 5 years, suggesting that these planets may often be rapidly destroyed. Eccentricity growth appears to be faster for more massive planets which may explain changes in the planetary mass function at small radii and may also predict a pile-up of lower mass planets, the sample of which is still incomplete.