The Neptunian ridge as a natural outcome of high-eccentricity tidal migration
A. Castro-Gonz’alez, V. Bourrier, D. Ehrenreich, D. J. Armstrong, A. C. M. Correia, M. Lendl
arXiv:2604.16300v1 Announce Type: new
Abstract: Recent occurrence-rate analyses show that the transition between the Neptunian desert and savanna is not smooth, but exhibits an overdensity of planets at $P_{rm orb} sim 3-6$ d, known as the Neptunian ridge. We confront the high-eccentricity tidal migration (HEM) scenario with this updated desert-ridge-savanna landscape. We map HEM tidal survival constraints onto the period-radius plane using empirically inferred mass-radius relations, and provide an independent consistency check in the period-density plane. The HEM tidal survival formalism reproduces the slope of the desert boundary across the sub-Neptune to super-Neptune/sub-Saturn regime ($1.8,R_{oplus} arXiv:2604.16300v1 Announce Type: new
Abstract: Recent occurrence-rate analyses show that the transition between the Neptunian desert and savanna is not smooth, but exhibits an overdensity of planets at $P_{rm orb} sim 3-6$ d, known as the Neptunian ridge. We confront the high-eccentricity tidal migration (HEM) scenario with this updated desert-ridge-savanna landscape. We map HEM tidal survival constraints onto the period-radius plane using empirically inferred mass-radius relations, and provide an independent consistency check in the period-density plane. The HEM tidal survival formalism reproduces the slope of the desert boundary across the sub-Neptune to super-Neptune/sub-Saturn regime ($1.8,R_{oplus}