Research

Pablo Benítez-Llambay, Leonardo Krapp, Ximena S. Ramos, Kaitlin M. Kratter, 2023,           ApJ, 952, 106.

Lega, E., Morbidelli, A., Nelson, R. P., Ramos, X. S., Crida, A., Bethune, W., Batygin, K., 2022, A&A, 658, A32.

We studied the impact of the accretion of gas driven by disk winds on the migration speed of giant planets embedded in low-viscosity adiabatic 3D protoplanetary disks. We mimicked the effects of a disk wind by applying a synthetic torque on a surface layer of the disk characterized by a prescribed column density ΣA so that it results in a disk accretion rate of ṀA = 10−8 Msun yr−1 . Disks with this structure are called ‘layered’ and the layer where the torque is applied is denoted as ‘active’. The main conclusion is that the migration rate of a gap-opening planet depends on the thickness of the accreting layer. 

Di Sisto, Romina P., Ramos, Ximena S., Gallardo, Tabaré, 2019, Icarus, 319, 828-839.

Following the previous study of the long-term dynamical stability of Jupiter Trojan asteroids (Di Sisto et al. 2014), here we demonstrated that escaped Trojans -those that are able to move away from the Lagrangian points- are able to contribute to other minor body populations in the Solar System.

C. Charalambous, J. G. Martí, C. Beaugé, X. S. Ramos, 2018, MNRAS, 477, 1414.

We present a series of dynamical maps for fictitious three-planet systems in initially circular coplanar orbits. These maps have unveiled a rich diversity resonant structure involving two or three planets, as well as indicating possible migration routes from secular to double resonances or pure three-planet commensurabilities. In the absence of adequate analytical models, these maps allowed us to evaluate their relative strengths and identify which could be relevant to the orbital evolution of three-planet systems.

Ramos. X. S., C. Charalambous, P. Benítez-Llambay, C. Beaugé, 2017, A&A, 602, A101.

We investigated possible configurations under the effects of migration when two planets are embedded in a protoplanetary disk. We performed N-body simulations to study the possible resonant configurations achieved by real system. As a complement, we have also developed an analytical model that allows us to reproduce the quasi-resonant dynamics observed in many Kepler exoplanetary systems. The main result is that these systems are compatible with type-I migration in a flared disk.

Benítez-Llambay, P., Ramos, X. S., Beaugé, C. & Masset, F. S., 2016., ApJ, 826, 1-13.

We developed a new method for performing long-term and long-range hydrodynamical simulations of migrating planets embedded in gaseous disks. This consists of a remapping technique where the primitive hydrodynamical quantities are remapped onto a new mesh, tracking the planets during their migration. In other words, we propose to adapt the mesh radially to follow the planets, considering adaptive resolution with distance as it migrates.

Ramos, X. S., Correa-Otto, J. A., Beaugé, C., 2015, CeMDA, 123, 453-479.

We studied the stability of an asteroid in the context of the restricted three-body problem, finding a new way to interpret the so-called resonance overlap criterion. We proposed a stability criterion by considering the intersection between first- and second-order mean motion resonances. We concluded that there are two limits: a lower limit given by the Hill stability criterion and an upper limit, given by the resonance overlap criterion. The first limit gives a sufficient condition for the asteroid orbit to be stable, while the second one gives a necessary condition for instability to occur. Of course, there is an intermediate zone where both can happen. This result is general, thus being applicable to any exo-planetary system.

Di Sisto, Romina P., Ramos, Ximena S., Beaugé, Cristián, 2014, Icarus, 243, 287-295.

We studied the long-term dynamical stability of Jupiter Trojan asteroids. It is very well known that there exists an asymmetry in the distribution of minor bodies around the Lagrangian points of Jupiter. We have studied this problem numerically. The main conclusion of our research is that part of the observed asymmetry must be primordial, and related to the capture/formation process of these asteroids.