The imprint of X-ray photoevaporation of planet-forming discs on the orbital distribution of giant planets — II. Theoretical predictions. (arXiv:2105.05908v2 [astro-ph.EP] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Monsch_K/0/1/0/all/0/1">Kristina Monsch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Picogna_G/0/1/0/all/0/1">Giovanni Picogna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ercolano_B/0/1/0/all/0/1">Barbara Ercolano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Preibisch_T/0/1/0/all/0/1">Thomas Preibisch</a>
Numerical models have shown that disc dispersal via internal photoevaporation
driven by the host star can successfully reproduce the observed pile-up of warm
Jupiters near 1-2 au. However, since a range of different mechanisms have been
proposed to cause the same feature, clear observational diagnostics of disc
dispersal leaving an imprint in the observed distribution of giant planets
could help to constrain the dominant mechanisms. We aim to assess the impact of
disc dispersal via X-ray driven-photoevaporation (XPE) onto giant planet
separations in order to provide theoretical constraints on the location and
size of any possible features related to this process within their observed
orbital distribution. For this purpose, we perform a set of 1D population
syntheses with varying initial conditions and correlate the gas giants’ final
parking locations with the X-ray luminosities of their host stars in order to
quantify observables of this process within the $L_mathrm{x}$-$a$-plane of
these systems. We find that XPE indeed creates an underdensity of gas giants
near the gravitational radius, with corresponding pile-ups inside and/or
outside of this location. However, the size and location of these features are
strongly dependent on the choice of initial conditions in our model, such as
the assumed formation location of the planets. XPE can strongly affect the
migration process of giant planets and leave potentially observable signatures
within the observed orbital separations of giant planets. However, due to the
simplistic approach employed in our model, which lacks a self-consistent
treatment of planet formation within an evolving disc, a quantitative analysis
of the final planet population orbits is not possible. Our results however
strongly motivate future studies to include realistic disc dispersal mechanisms
into global planet population synthesis models.
Numerical models have shown that disc dispersal via internal photoevaporation
driven by the host star can successfully reproduce the observed pile-up of warm
Jupiters near 1-2 au. However, since a range of different mechanisms have been
proposed to cause the same feature, clear observational diagnostics of disc
dispersal leaving an imprint in the observed distribution of giant planets
could help to constrain the dominant mechanisms. We aim to assess the impact of
disc dispersal via X-ray driven-photoevaporation (XPE) onto giant planet
separations in order to provide theoretical constraints on the location and
size of any possible features related to this process within their observed
orbital distribution. For this purpose, we perform a set of 1D population
syntheses with varying initial conditions and correlate the gas giants’ final
parking locations with the X-ray luminosities of their host stars in order to
quantify observables of this process within the $L_mathrm{x}$-$a$-plane of
these systems. We find that XPE indeed creates an underdensity of gas giants
near the gravitational radius, with corresponding pile-ups inside and/or
outside of this location. However, the size and location of these features are
strongly dependent on the choice of initial conditions in our model, such as
the assumed formation location of the planets. XPE can strongly affect the
migration process of giant planets and leave potentially observable signatures
within the observed orbital separations of giant planets. However, due to the
simplistic approach employed in our model, which lacks a self-consistent
treatment of planet formation within an evolving disc, a quantitative analysis
of the final planet population orbits is not possible. Our results however
strongly motivate future studies to include realistic disc dispersal mechanisms
into global planet population synthesis models.
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