Irradiation-driven escape of primordial planetary atmospheres III. Revised planetary parameters and mass-loss rates for nearby gaseous planets after Gaia DR2. (arXiv:2208.01650v1 [astro-ph.EP])

Irradiation-driven escape of primordial planetary atmospheres III. Revised planetary parameters and mass-loss rates for nearby gaseous planets after Gaia DR2. (arXiv:2208.01650v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Spinelli_R/0/1/0/all/0/1">R. Spinelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gallo_E/0/1/0/all/0/1">E. Gallo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Haardt_F/0/1/0/all/0/1">F. Haardt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caldiroli_A/0/1/0/all/0/1">A. Caldiroli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biassoni_F/0/1/0/all/0/1">F. Biassoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Borsa_F/0/1/0/all/0/1">F. Borsa</a>

In this paper we leverage Gaia parallactic distances to deliver revised
estimates of planetary parameters and extreme ultraviolet (EUV) fluxes for a
distance-limited ($lesssim 100$ pc) sample of 27 gaseous planets — from
super-Earths to hot Jupiters — with publicly available X-ray observations.
Notably, the revised mass and radius imply a Saturn-like density ($0.86 pm
0.09$ g cm$^{-3}$) for HD 149026 b — consistent with the lowest values
reported in the literature — thus removing the need for a high metal fraction.
For 20 planets with X-ray detected host stars we also derive updated
atmospheric mass outflow rates making use of the 1D photoionization
hydrodynamics code ATES. We note, however, how X-ray variability combined with
large uncertainties in the conversion between X-rays and EUV fluxes severely
affects the inferred instantaneous mass loss rates, and thus the ability to
constrain/predict the integrated mass loss over a planet’s lifetime.

In this paper we leverage Gaia parallactic distances to deliver revised
estimates of planetary parameters and extreme ultraviolet (EUV) fluxes for a
distance-limited ($lesssim 100$ pc) sample of 27 gaseous planets — from
super-Earths to hot Jupiters — with publicly available X-ray observations.
Notably, the revised mass and radius imply a Saturn-like density ($0.86 pm
0.09$ g cm$^{-3}$) for HD 149026 b — consistent with the lowest values
reported in the literature — thus removing the need for a high metal fraction.
For 20 planets with X-ray detected host stars we also derive updated
atmospheric mass outflow rates making use of the 1D photoionization
hydrodynamics code ATES. We note, however, how X-ray variability combined with
large uncertainties in the conversion between X-rays and EUV fluxes severely
affects the inferred instantaneous mass loss rates, and thus the ability to
constrain/predict the integrated mass loss over a planet’s lifetime.

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