Reseach
My research interests during the last 5 years have been focused on the study of different
aspects of the debris disk phenomena, including:
Modeling of Debris Disk Structure:
The modeling of debris disk structure is a potential
planet detection technique sensitive to long-period planets. The gravitational
perturbations of a planet on the dust-producing planetesimals and/or
on the dust particles themseleves can produce structure on the debris disk. If the disk is radiatively-dominated, < 0.001M(Earth),
as is the case of the Kuiper Belt dust disk, the
the disk structure is created because the dust grains migrate inward
due to the effect of Poynting-Robertson drag, eventually coming in
resonance with the planet and/or crossing its orbit (with the latter likely resulting in
gravitational ejection from the system).
If the disk is collisionally-dominated, > 0.001M(Earth),
the collisional lifetime of the dust grains is short, and therefore, the grains
may not survive long enough to come into resonance with an inner planet. However, the structure
of the Kuiper Belt Objects gives strong evidence that Neptune migrated outward. This process
may have also taken place in other planetary systems, where the outward migration
of a planet could have scattered planetesimals out of the system or trapped
them into Plutino-like orbits. Because the larger dust particles trace the location
of the parent bodies, this outward migration can strongly affect the debris
disk structure.
Solar System Kuiper Belt Dust:
The dust produced in the Kuiper Belt region extends throughout the Solar System due to Poynting-Robertson drag, forming a dust disk of wide radial extend. Some of its properties resemble those of extra-solar debris disks, and as such its study can help us understand the types of processes which might be at play in other planetary systems. The study of the Kuiper Belt dust is also important for the study of the small population
of (undetected) Kuiper Belt Objects, for understanding the dynamical evolution of the Solar System,
and for estimating a potential source of foreground contamination for cosmological observations.
Observations of Debris Disks with Spitzer:
Spitzer is carrying out spectrophotometric observations of hundreds of circumstellar
disks most of which are spatially unresolved. The study of the spectral energy distributions (SEDs) of the disks can help us diagnose
the radial distribution of dust, allowing us to identify targets where the
dynamical imprints of embedded giant planets may be present.
This is one of the goals of the Spitzer Legacy Program
"Formation and Evolution of Planetary Systems" (FEPS) .
Ejection of Debris from Planetary Systems:
Gravitational scattering by massive planets is very efficient at
ejecting dust particles from a planetary system. This can result in a dust depleted region inside the orbit of the
planet, may be explaining some of the inner cavities seen in spatially-resolved images of debris disks (or inferred from their SEDs). The ejection of debris can also have interesting astrobiological implications, as debris may be trasferred among planetary systems through
low velocity chaotic orbits.
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Created: Nov 6, 2006
Last Modified: Nov 6, 2006