干旱区生态环境知识资源中心(Arid): The Sub-Neptune Desert and Its Dependence on Stellar Type: Controlled by Lifetime X-Ray Irradiation

Arid

DOI	10.3847/1538-4357/ab1095
	The Sub-Neptune Desert and Its Dependence on Stellar Type: Controlled by Lifetime X-Ray Irradiation
	McDonald, George D.1; Kreidberg, Laura 2,3; Lopez, Eric 4,5
通讯作者	McDonald, George D.
来源期刊	ASTROPHYSICAL JOURNAL
ISSN	0004-637X
EISSN	1538-4357
出版年	2019
卷号	876 期号:1
英文摘要	Short-period sub-Neptunes with substantial volatile envelopes are among the most common type of known exoplanets. However, recent studies of the Kepler population have suggested a dearth of sub-Neptunes on highly irradiated orbits, where they are vulnerable to atmospheric photoevaporation. Physically, we expect this photoevaporation desert to depend on the total lifetime X-ray and extreme ultraviolet flux, the main drivers of atmospheric escape. In this work, we study the demographics of sub-Neptunes as a function of lifetime exposure to high-energy radiation and host-star mass. We find that for a given present-day insolation, planets orbiting a 0.3 M-circle dot star experience similar to 100x more X-ray flux over their lifetimes versus a 1.2 M-circle dot star. Defining the photoevaporation desert as a region consistent with zero occurrence at 2 sigma, the onset of the desert happens for integrated X-ray fluxes greater than 1.43 x 10(22) to 8.23 x 10(20) as a function of planetary radii for 1.8-4 R-circle plus. We also compare the location of the photoevaporation desert for different stellar types. We find much greater variability in the desert onset in the bolometric flux space compared to the integrated X-ray flux space, suggestive of photoevaporation driven by steady-state stellar X-ray emissions as the dominant control on desert location. Finally, we report tentative evidence for the sub-Neptune valley, first seen around Sun-like stars, for M&K dwarfs. The discovery of additional planets around low-mass stars from surveys such as the Transiting Exoplanet Survey Satellite mission will enable detailed exploration of these trends.
英文关键词	planets and satellites: atmospheres planets and satellites: gaseous planets planets and satellites: physical evolution X-rays: stars
类型	Article
语种	英语
国家	USA
开放获取类型	Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000466569500009
WOS关键词	SUPER-EARTHS ; MASS-LOSS ; PLANETS ; EVOLUTION ; KEPLER ; EVAPORATION ; RADIATION ; SIZE ; UV
WOS类目	Astronomy & Astrophysics
WOS研究方向	Astronomy & Astrophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/214436
作者单位	1.Georgia Inst Technol, Sch Earth & Atmospher Sci, 311 Ferst Dr, Atlanta, GA 30332 USA; 2.Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA; 3.Harvard Soc Fellows, 78 Mt Auburn St, Cambridge, MA 02138 USA; 4.NASA, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA; 5.NASA, GSFC, GSFC Sellers Exoplanet Environm Collaborat, Greenbelt, MD 20771 USA
推荐引用方式 GB/T 7714	McDonald, George D.,Kreidberg, Laura,Lopez, Eric. The Sub-Neptune Desert and Its Dependence on Stellar Type: Controlled by Lifetime X-Ray Irradiation[J],2019,876(1).
APA	McDonald, George D.,Kreidberg, Laura,&Lopez, Eric.(2019).The Sub-Neptune Desert and Its Dependence on Stellar Type: Controlled by Lifetime X-Ray Irradiation.ASTROPHYSICAL JOURNAL,876(1).
MLA	McDonald, George D.,et al."The Sub-Neptune Desert and Its Dependence on Stellar Type: Controlled by Lifetime X-Ray Irradiation".ASTROPHYSICAL JOURNAL 876.1(2019).