The current giant planet region is a transitional zone where transneptunian objects (TNOs) cross in their way to becoming Jupiter Family Comets (JFCs). Their dynamical behavior is conditioned by the intrinsic dynamical features of TNOs and also by the encounters with the giant planets. We address the Giant Planet Crossing (GPC) population (those objects with $5.2$ au $ 100$ km and $\sim 10^8$ with $D > 1$ km in the current population. The contribution from other sources is considered negligible. The mean lifetime in the Centaur zone is 7.2 Myr, while the mean lifetime of SDOs in the GPC zone is of 68 Myr. The latter is dependent on the initial inclination, being the ones with high inclinations the ones that survive the longest in the GPC zone. There is also a correlation of lifetime with perihelion distance, where greater perihelion leads to longer lifetime. The dynamical evolution of observed GPCs is different for prograde and retrograde objects. Retrograde GPCs have lower median lifetime than prograde ones, thus experiencing a comparatively faster evolution. However, it is probable that this faster evolution is due to the fact that the majority of retrograde GPCs have low perihelion values and then, lower lifetimes.

中文翻译：

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半人马和巨行星穿越种群：起源和分布

当前的巨行星区域是一个过渡带，海王星天体 (TNO) 在此过渡到成为木星家族彗星 (JFC)。它们的动力学行为受 TNO 的内在动力学特征以及与巨行星的相遇所制约。我们解决了巨型行星穿越 (GPC) 群体（当前群体中 $5.2$ au $ 100$ km 和 $\sim 10^8$ $D > 1$ km 的那些物体。其他来源的贡献被认为可以忽略不计。 Centaur 区的平均寿命为 7.2 Myr，而 GPC 区的 SDO 的平均寿命为 68 Myr。后者取决于初始倾角，高倾角的那些在 GPC 中存活时间最长带。还有寿命与近日点距离的相关性，更大的近日点导致更长的寿命。对于顺行和逆行物体，观测到的 GPC 的动态演化是不同的。逆行 GPC 的中值寿命低于顺行 GPC，因此进化速度相对较快。然而，这种更快的进化很可能是由于大多数逆行 GPC 的近日点值较低，因此寿命较短。