RESEARCH
DOCTORAL THESIS, UNIVERSITY OF FLORIDA
Project: Investigating the structure and source of the zodiacal cloud through dynamics and light scattering.
My primary focus is the modeling of the dynamics of the both the known asteroidal Zodiacal Dust Bands and the extenstion of this model to the zodiacal cloud as a whole, i.e. inside 2 AU. This modeling will allow us to determine not only if the same few asteroid families that are responsible for the dust bands are also responsible for the background cloud. When the cloud model is completed, we will be able to answer fundamental questions about the percentages of commetary/asteroidal material to the cloud, as well as the radial sturcture of the cloud. Using line of sight observations from IRAS, COBE, MSX and in the near future, Spitzer, we can compare our models directly to the current observations. The zodiacal cloud has several inherent asymmetries that will allow us more observable features to model. If we can correctly model both the shape and the flux of the observations using only the orbits of the asteroidal particles created in the breakups of the asteroid families known to have created the dust bands, then we have a substantial case for the cloud being almost entirely asteroidal in nature, possibly even steming from a single asteroid family, Veritas. Knowlege of the nature of cloud and the source allows us to understand the dynamics of particles near the earth, which can have an effect on both our climate and our spacecraft. In addition to the dynamics, I will be using the microwave facility in the Laboratory for Astrophysics to model possible scenarios for the precursor asteroids to the bands and possibly the entire cloud. Comparison of the modeled scattering, both intensity and polarization, with that of the Zodiacal Dust, through different wavelengths, will allow us to investigate the scale of the structure of the dust in the Zodiacal cloud and determine the extent to which the precursor asteroids were differentiated. This knowledge will allow us to draw conclusions, not only to the formation of these asteroids, but also shed some light on the unresolved issues involved in the formation of our own solar system.
Laboratory for Astrophysics
MASTER'S THESIS, UNIVERSITY OF FLORIDA
This is my master's thesis research which I completed in May of 2003.
Mentor: Dr. Bo Gustafson
Project: Dust Capture Facility on the International Space Station
The solar system is full of dust and meteoroids and the Earth is constantly bombarded by samples from a variety of sources. Many of these samples represent fragments of material from which the Earth and other planets formed and represent some of the oldest materials in the solar system. The collection and study of these particles would give much information about the early universe. Proposed is a dust capture facility on the International Space Station. The capture medium of choice is aerogel due to its ability to capture and decelerate high-velocity particles without substantially melting or otherwise modifying their component materials. The facility will consist of aerogel squares mounted on an aluminum frame, from which the aerogel squares will be returned to earth for analysis. The magnitude and direction of the particle's velocity vector will need to be deduced from the track in the aerogel. In order to determine where on the aerogel the impact took place, we will use time-delay measurements of the acoustic wave created upon impact. The speed of acoustic energy in the aerogel is only 200 m/s and so the travel through the aluminum can be considered instantaneous. Thus using three acoustic sensors mounted on the aluminum, the precise location of the impact can be determined based on the delays of the acoustic pulses from each side of the aerogel. Using a combination of theoretical modeling (inlcuding IDL simulation programs) and laboratory data from the hypervelocity gun, these issues will be addressed.
1999 REU AT STANFORD RESEARCH INSTITUE, Menlo Park,CA
This was a "Research Experience for Undergraduates" program that I did in the summer of 1999 on the Terrestrial Nightglow. REU is a division of the National Science Foundation. My work was funded by the NASA Solar Project.
Mentors: Dr. Tom Slanger, Dr. Philip Cosby, and Dr. David Huestis
Project:The Contribution of Keck/Hires to Terrestrial Nightglow
The unsurpassed resolution and sensitivity of the HIRES spectrograph at the 10-m Keck I telescope creates new opportunities for investigating the emissions of the Earth's atmosphere. Through collaborations between astronomers and aeronomers, diagnostic information about the terrestrial middle and upper atmosphere can be attained. This research is intended to provide a foundation for selecting and interpreting new measurements from the ground, from rockets and balloons, and from space platforms. We need a good model of terrestrial and extraterrestrial sources of emission and absorption features to take advantage of the improvements in optical instruments. Because the real atmosphere is variable on time scales of season, time-of day, or even minutes, we need schemes of calibrations that can be acquired with just a few measurements. The overall objective is to develop a comprehensive model of terrestrial nightglow emissions with the target of identifying and characterizing the nightglow emissions that provide new diagnostics for ionospheric processes.
During the course of my work, we were able to verify the existence of several new fine structure levels of Oxygen2. These levels were unproven before this time due to their extreme instability causing them to be too unstable to survive collisions with container walls in a laboratory type experiment. We were able to overcome this through measuring them in the upper atmosphere and, in a sense, using the atmosphere as a laboratory, in which the container has no walls.
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2000 ULTRAFAST OPTICS AT GEORGIA TECH, Atlanta,GA
This was a project I worked on for almost a year at Georgia Tech with Dr. Rick Trebino and the Ultrafast LASER Group.
I like to play with expensive toys.
This was a little device at Stanford designed to detect chlorinated aromatic compounds, especially dioxin and furan species through supersonic-cooled, resonance enhanced multiphoton ionization (Jet-REMPI) combined with time-of-flight mass spectrometry. It wasn't part of my project, but I got to play around with it and learn how it worked while I was there.