JpGU-AGU Joint Meeting 2020

講演情報

[E] ポスター発表

セッション記号 P (宇宙惑星科学) » P-AE 天文学・太陽系外天体

[P-AE22] 系外惑星

コンビーナ:生駒 大洋(東京大学 大学院理学系研究科 地球惑星科学専攻)、成田 憲保(東京大学)、藤井 友香(国立天文台)

[PAE22-P14] Bayesian inference of occurrence rates of super-Earths in systems with cold-Jupiters around low-mass stars

*荻原 正博1原川 紘季2 (1.国立天文台、2.Subaru Telescope)

キーワード:スーパーアース、コールドジュピター、低質量星

Transit observations of exoplanets with space telescopes (e.g., Kepler) have revealed an abundant class of close-in super-Earths (SEs). The occurrence rate of giant planets in wide orbits (also known as cold Jupiters or CJs) can be studied using the data obtained via radial velocity (RV) observations, which have been conducted for more than 20 years. As the occurrence rates of SEs and CJs are estimated, the correlation between SEs and CJs can also be discussed. According previous studies, it is likely that CJs coexist with SEs, and this is expressed by a high conditional probability P(SE|CJ) of about 90%.

Recently, observations of super-Earths around low-mass stars have attracted increasing attention. In fact, several new RV surveys of M dwarfs have been initiated; these operations include IRD-SSP with the Subaru telescope and CARMENES. We are interested in whether the conditional probability of P(SE|CJ) is also high around M dwarfs.

In this study, we present an estimate of the conditional probability of P(SE|CJ) around M dwarfs using Bayes’ inference. We find that the conditional probability of the existing SEs under the existence of CJs is quite high even around M dwarfs. We also discuss whether the existence of CJs enhances the growth of SEs. It is likely that the high conditional probability of P(SE|CJ) is simply a reflection of the high amount of solids available for planet formation. For a more robust discussion, more RV observation data are needed. In addition, dynamical simulations that include the effects of CJs on SEs are also required.