arXiv subjects

Ignacio Mosqueira

Publications and source records attributed to Ignacio Mosqueira.

4 recordsLinked to original sources

arXiv2026

PDS 70 c and SR 12 c: Observational Constraints on Giant-Planet and Satellite Formation

PDS~70~c and SR~12~c are the only bound planetary-mass objects with secure cold submillimeter disk detections. Together, these systems constrain giant-planet growth and satellite formation. The PDS~70 planets exhibit remarkable parallels to the Jupiter--Saturn pair in our Solar System. Both PDS~70 planets accrete within one shared gap, which links their final masses, the material reaching each Hill sphere, and the properties of the circumplanetary disk. Planetary torques deplete the finite interplanetary reservoir, causing circumplanetary supply to decline as the protoplanets open a circumstellar gap. SR~12~c separates the planetary-growth and satellite-formation timescales: gas and solids survive even though its current mass-growth timescale is $(1.9\pm0.6)\times10^9$~yr. For PDS~70~c, the 855-$\mu$m flux implies $0.007$--$0.031\,\Mearth$ of dust at 26~K in the optically thin limit. A fully dust-dominated, uniform 22--26-K optically thick emitter has an equivalent coplanar radius of $0.58$--$0.66$~au, while a fiducial radial temperature profile yields an equivalent radius of approximately 0.46~au. The continuum constraints overlap the 0.5--1.5~au circularization range estimated by ballistic calculations of late-stage gap-fed inflow. We find that the PDS~70 constraints are consistent with our \SEMM{} satellite-formation model (Mosqueira \& Estrada 2003a,b, submitted in 2001). Thus the observations provide strong support for a quiescent, solids-enhanced satellite-forming environment, coupled in the early stages to planetary-gap evolution.

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arXiv2009

Deciphering the Origin of the Regular Satellites of Gaseous Giants - Iapetus: the Rosetta Ice-Moon

Here we show that Iapetus can serve to discriminate between satellite formation models. Its accretion history can be understood in terms of a two-component gaseous subnebula, with a relatively dense inner region, and an extended tail out to the location of the irregular satellites, as in the SEMM model of Mosqueira and Estrada (2003a,b). Following giant planet formation, planetesimals in the feeding zone of Jupiter and Saturn become dynamically excited, and undergo a collisional cascade. Ablation and capture of planetesimal fragments crossing the gaseous circumplanetary disks delivers enough collisional rubble to account for the mass budgets of the regular satellites of Jupiter and Saturn. This process can result in rock/ice fractionation provided the make up of the population of disk crossers is non-homogeneous, thus offering a natural explanation for the marked compositional differences between outer solar nebula objects and those that accreted in the subnebulae of the giant planets. Consequently, our model leads to an enhancement of the ice content of Iapetus, and to a lesser degree those of Ganymede, Titan and Callisto, and accounts for the (non-stochastic) compositions of these large, low-porosity outer regular satellites of Jupiter and Saturn. (abridged)

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arXiv2009

Planetesimals and Satellitesimals: Formation of the Satellite Systems

The origin of the regular satellites ties directly to planetary formation in that the satellites form in gas and dust disks around the giant planets and may be viewed as mini-solar systems, involving a number of closely related underlying physical processes. The regular satellites of Jupiter and Saturn share a number of remarkable similarities that taken together make a compelling case for a deep-seated order and structure governing their origin. Furthermore, the similarities in the mass ratio of the largest satellites to their primaries, the specific angular momenta, and the bulk compositions of the two satellite systems are significant and in need of explanation. Yet, the differences are also striking. We advance a common framework for the origin of the regular satellites of Jupiter and Saturn and discuss the accretion of satellites in gaseous, circumplanetary disks. Following giant planet formation, planetesimals in the planet's feeding zone undergo a brief period of intense collisional grinding. Mass delivery to the circumplanetary disk via ablation of planetesimal fragments has implications for a host of satellite observations, tying the history of planetesimals to that of satellitesimals and ultimately that of the satellites themselves. By contrast, irregular satellites are objects captured during the final stages of planetary formation or the early evolution of the Solar System; their distinct origin is reflected in their physical properties, which has implications for the subsequent evolution of the satellites systems.

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arXiv2009

Formation of Jupiter and Conditions for Accretion of the Galilean Satellites

We present an overview of the formation of Jupiter and its associated circumplanetary disk. Jupiter forms via a combination of planetesimal accretion and gravitational accumulation of gas from the surrounding solar nebula. The formation of the circumjovian gaseous disk, or subnebula, straddles the transitional stage between runaway gas accretion and Jupiter's eventual isolation from the solar disk. This isolation, which effectively signals the termination of Jupiter's accretion, takes place as Jupiter opens a deep gas gap in the solar nebula, or the solar nebula gas dissipates. We describe the conditions for accretion of the Galilean satellites, including the timescales for their formation, and mechanisms for their survival, all within the context of key constraints for satellite formation models. The environment in which the regular satellites form is tied to the timescale for circumplanetary disk dispersal, which depends on the nature and persistence of turbulence. In the case that subnebula turbulence decays as gas inflow wanes, we present a novel mechanism for satellite survival involving gap opening by the largest satellites. On the other hand, assuming that sustained turbulence drives subnebula evolution on a short timescale compared to the satellite formation timescale, we review a model that emphasizes collisional processes to explain satellite observations. We briefly discuss the mechanisms by which solids may be delivered to the circumplanetary disk. However, we expect that planetesimal delivery mechanisms likely provide the bulk of material for satellite accretion.

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