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2007 Michelson Fellowship Awards Announced
4 Post-Doctoral Scholars, 3 Graduate Student Fellows Selected
The Michelson Science Center (MSC) received 36 postdoc and 16 graduate student applications as of the application deadline on November 2, 2006. After a long, difficult, and carefully considered selection process, we are proud to announce the following new Michelson Fellows, along with the fellowship host institutions and advisors:Postdocs:
Graduate Students:
The selection panel felt that these promising young researchers showed the greatest potential for advancing NASA's Navigator Program, in pursuit of detecting and characterizing planets about nearby stars.
Abstracts for the fellows are below.
More information on the 2007 call for Michelson Postdoc and Graduate Student Fellowships is available in the original announcement.
Postdocs:
Daniel Fabrycky - "Dynamical Detection And Migration Of Multiple-Body Planetary Systems"
With the discovery of planets orbiting other stars came numerous examples of multiple body systems: as of October 2006, 20 stars are known to host multiple planets and 31 planet-hosting stars are known to have at least one stellar companion. In our own planetary system, the planets only slightly perturb each other’s orbits because of their relatively small eccentricities and inclinations and their generous spacing. The planets of other stars, in contrast, generally have a strong dynamical coupling to one another. If one of the planets transits the host star, transit-timing measurements will exquisitely constrain the system’s parameters and may even permit the detection of additional planets. I will develop a theoretical and statistical framework to diagnose the dynamical state of planetary systems by such measurements. The long-term perturbation of a planet by a companion star can drive its orbit to high eccentricity; with the help of tidal dissipation the planet may migrate to become a hot Jupiter. I will make theoretical models of such evolution to constrain the histories of planets in binaries on the basis of their orbits observable by Navigator observatories SIM and TPF.
Michael Fitzgerald - "Architectures of Planetary Systems at High Contrast"
Circumstellar disks are ideal places to search for signs of planets and their formation. The grains in debris disks are generated through the attrition and evaporation of primitive planet-building material. Their scattered light is only seen at high contrast, and the advancement of coronagraphic techniques promises to greatly increase the number of resolved systems. I seek to maximize the sensitivity of diffraction-limited adaptive optics coronagraphy to both planets and debris disks by implementing a true roll deconvolution scheme. I will use the statistics and structure of speckles to facilitate the sifting of stellar point spread functions from circumstellar emission. I will carry out an observing campaign to resolve the disks, reveal their architectures, probe grain sizes and composition, and potentially detect young, self-luminous jupiters. Coupled with the advance in data processing, these observations are sensitive to indirect signatures of planets. Moreover, they trace the locations and evolution of primitive solid material. These advances in high-contrast technique will have direct application to instruments and missions currently in development. Understanding the diversity of debris disk architectures promises to uncover the mechanisms governing planet formation and disk evolution.
Andrea Isella - "Planet Formation In Pre-Main Sequence Disks"
As a research project at Caltech/MSC I propose a multi-scale study of circumstellar disks based on Keck and CARMA interferometric observations of pre-main sequence stars. The aim of the project is to understand where and when planet formation take place and how this process modifies the structure of circumstellar disks. Infrared and millimeter observations will allow to characterize the disk structure at all distances from the central star, from the dust evaporation radius, at fraction of AU, until the disk outer radius, at hundreds of AUs. The data analysis, performed in the framework of the disk models developed during my Ph.D., will allow to determine physical properties of the circumstellar material (i.e., disk mass, gas and dust radial distribution and temperature, dust size and composition, gas cinematic), with the aim of investigating the dynamical perturbations driven by forming planets on the surrounding dust and gas. The proposed combination of Keck and VLTI observations will allow a fundamental improvement of the uv-plane coverage, bringing to a real breakthrough in our knowledge of pre-main sequence disks.
Hannah Jang-Condell -
"Three-Dimensional Radiative Transfer in Disks with Planets"
(see illustrative movie)
I propose to apply three-dimensional radiative transfer modeling to various types of disk-planet interactions, determining observable consequences as well as implications for planet formation theory. One application is to determine observable signatures of both disk instability and core accretion, to help settle to debate over which mechanism gives rise to giant planets. A second application is to model inner holes and gaps in disks to interpret resolved images of disk structure as well as to determine how the holes and gaps might form. A third application is to determine how much slowing of Type I migration of planets occurs from temperature perturbations caused by shadowing in the disk. I also hope to improve the modeling of dust properties in my disk calculations and address the freezing out of volatiles in shadows created by planets. I will work with researchers at both University of Maryland and NASA-Goddard Space Flight Center in my work.
Graduate Students:
Katie Morzinski - "Imaging Extrasolar Planets with MEMS Deformable Mirrors"
Exciting developments
in the fields of adaptive optics, coronagraphy, interferometry, and
image processing will furnish direct images of extrasolar planets within
the next decade. This feat requires high-order wavefront correction
systems with low residual error, whether on Earth or in space. To this
end, the deformable mirror (DM) must exhibit exemplary performance, with
thousands of well-controlled actuators. Micro-electrical mechanical
systems (MEMS) technology offers reliable, compact, high-actuator-count
DMs at an accessible cost. At the UCSC Laboratory for Adaptive Optics,
MEMS have been shown to operate in closed-loop with sub-nanometer
flattening, stability, and repeatability. I propose to further these
experiments to address: 1. operational performance limitations; 2.
modeling and control algorithms; and 3. on-sky testing. First, through
complete understanding of MEMS performance under typical aberrations,
requirements can be specified to compensate for stroke limitations.
Second, improved MEMS modeling and control will reduce residual
wavefront errors and will enable open-loop MEMS control for advanced
wavefront-correction architectures. Finally, operating MEMS on-sky will
prove the technology in the observing environment. These studies will
not only inform the design of the Gemini Planet Imager, but will also
benefit space missions like TPF-C that require high-order DMs for
wavefront control.
Matt Troutman - "Using Near-Infrared CO Emission to Identify the Presence of Planets in Transitional Disks"
Recent observations of
spectral energy distributions of young stars have revealed exciting
detail in transitional disks, which are the birthplace of planets. Data
from Spitzer have allowed detailed modeling of the dust distribution in
the inner disk, which show AU-sized gaps that may be caused by a massive
planet. However there are other scenarios, where a planet does not
exist, that produce identical spectral energy distributions (SEDs).
Therefore, it is crucial to probe the gas in the inner disk to determine
if there truly is a planet in the transitional disk. A good tracer of
gas in the inner disk is CO, with ro-vibrational lines in atmospheric
windows in the near-infrared. This research will look at ro-vibrational
CO emission in transitional disks in order to determine if a planet
truly exists.
Ming Zhao - "Direct Detection and Characterization of Hot Jupiters Using Closure Phase"
We propose to use the closure phase and differential phase measurements obtained with the MIRC combiner at the CHARA array to directly detect and characterize nearby “hot Jupiters”. CHARA-MIRC is currently a unique ground-based facility that combines the highest (milli-arcsecond) angular resolution with high contrast imaging. We demonstrate that, under precise calibration schemes combined with high enough sensitivity, CHARA-MIRC will be able to detect emission from hot Jupiters. This project will consists of three parts: 1. Develop calibration and data reduction tools for MIRC; 2. Test these tools and schemes on scientific objects with CHARA-MIRC observations; 3. On sky test of detecting nearby hot Jupiters and characterizing succeeded dectections with available planetary atmospheric models. This work will be a substantial part of my Ph.D thesis and will be conducted under Prof. Monnier’s instruction at the University of Michigan.
Last Updated:
15 Feb 2007