EUV-driven mass-loss of protoplanetary cores with hydrogen-dominated atmospheres: the influences of ionization and orbital distance

Author(s)
N V Erkaev, Helmut Lammer, P Odert, K. G Kislyakova, Colin Johnstone, Manuel Güdel, Maxim L. Khodachenko
Abstract

We investigate the loss rates of the hydrogen atmospheres of terrestrial planets with a range of masses and orbital distances by assuming a stellar extreme ultraviolet (EUV) luminosity that is 100 times stronger than that of the current Sun. We apply a 1D upper atmosphere radiation absorption and hydrodynamic escape model that takes into account ionization, dissociation and recombination to calculate hydrogen mass-loss rates. We study the effects of the ionization, dissociation and recombination on the thermal mass-loss rates of hydrogen-dominated super-Earths and compare the results to those obtained by the energy-limited escape formula which is widely used for mass-loss evolution studies. Our results indicate that the energy-limited formula can to a great extent over- or underestimate the hydrogen mass-loss rates by amounts that depend on the stellar EUV flux and planetary parameters such as mass, size, effective temperature and EUV absorption radius.

Organisation(s)
Department of Astrophysics
External organisation(s)
Russian Academy of Sciences, Österreichische Akademie der Wissenschaften (ÖAW), Karl-Franzens-Universität Graz, N. I. Lobachevsky State University of Nizhny Novgorod, University of Texas, Austin
Journal
Monthly Notices of the Royal Astronomical Society
Volume
460
Pages
1300 - 1309
No. of pages
10
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stw935
Publication date
08-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/83aacdbf-82cd-4c57-8523-94d39291ad5c