The imprint of X-ray photoevaporation of planet-forming discs on the orbital distribution of giant planets

Abstract

High-energy radiation from a planet host star can have strong influence on the final habitability of a system through several mechanisms. In this context we have constructed a catalogue containing the X-ray luminosities, as well as basic stellar and planetary properties of all known stars hosting giant planets (> 0.1 M_J) that have been observed by the Chandra X-ray Observatory, XMM-Newton, and/or ROSAT. Specifically in this paper we present a first application of this catalogue to search for a possible imprint of X-ray photoevaporation of planet-forming discs on the present-day orbital distribution of the observed giant planets. We found a suggestive void in the semimajor axis, a, versus X-ray luminosity, L_x, plane, roughly located between a ∼ 0.05-1 au and L_x ∼ 10²⁷-10^{29} erg s^{-1}, which would be expected if photoevaporation played a dominant role in the migration history of these systems. However, due to the small observational sample size, the statistical significance of this feature cannot be proven at this point.