Faculty Mentor

Ashley Kehoe


The zodiacal cloud is the Solar System debris disk in which the Earth’s orbit is located. The dust that comprises the cloud comes from cometary, asteroidal, interstellar, and other source populations, but the relative ratios have proven hard to determine. However, asteroidal and cometary particles typically have different types of orbits, with asteroidal particles having more circular and lower inclination orbits than cometary particles. Accordingly, the relative velocities of these groups of particles with respect to Earth are also different, and measurements of these relative velocities can help distinguish between the sources. The spectrum of the zodiacal light contains solar absorption lines that are Doppler-shifted by moving dust particles. It is possible to determine dust particle velocities by observing the Doppler-shifted zodiacal light using the Wisconsin H-alpha Mapper (WHAM) — a specialized Fabry-Perot spectrometer. Focusing on a pair of scattered solar Mg I Fraunhofer lines, we have recently begun a three-year observing campaign with WHAM. In order to interpret these observations we need to produce synthetic observations of how different orbital distributions of dust particles would shift and modify the observed spectral lines. Comparing these synthetic spectra to the actual observations will allow us to constrain the sources of the dust composing the zodiacal cloud. Here I present an overview of this new project and my work in analyzing the Ipatov et al (2008) code that will be altered to generate the synthetic spectra.



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