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The X-Ray Variability Of Seyfert Galaxies, Kevin Marshall Dec 2006

The X-Ray Variability Of Seyfert Galaxies, Kevin Marshall

Physics and Astronomy Dissertations

Strong and variable X-ray emission has long been known to be a universal property of active galaxies. However, despite years of study, the exact nature of the variability remains relatively unknown. We present here results of a multi-year monitoring campaign of a sample of Seyfert galaxies (3C 120, Mkn 509, 3C 390.3, and Akn 120), carried out using the Rossi X-ray Timing Explorer (RXTE). For Mkn 509, we also present results of optical monitoring. Mkn 509 shows a strong correlation between X-ray and optical variations, with the optical leading the X-ray by 25 days. We also investigate the rms-flux relationship …


Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne Jan 2006

Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne

Theses and Dissertations

The processes leading to the widespread presence of crystalline silicates throughout the galaxy and the origin of silicon nanoparticles thought to be responsible for the observed extended red emission in diffuse galactic background are still far from being understood. One of the most abundant oxygen bearing species in molecular astronomical regions is SiO. It has been conjectured that silicate formation probably proceeds via the agglomeration of these molecular species; however there are no studies to reveal the microscopic mechanism. We have used a synergistic approach combining experiments in molecular beams and first principles theoretical calculation to demonstrate that the passage …


Science Icebreaker Activities: An Example From Gravitational Wave Astronomy, Michelle B. Larson, Louis J. Rubbo, Kristina D. Zaleski, Shane L. Larson Jan 2006

Science Icebreaker Activities: An Example From Gravitational Wave Astronomy, Michelle B. Larson, Louis J. Rubbo, Kristina D. Zaleski, Shane L. Larson

All Physics Faculty Publications

At the beginning of a class, workshop, or meeting, an icebreaker activity is often used to help loosen up the group and get everyone talking. When used as a precursor to group learning, the icebreaker fosters communication so later activities function more smoothly. Science-based icebreaker activities serve the purpose of a traditional icebreaker, while also introducing science content to the audience. The content of the icebreaker may or may not be related to the topic of the upcoming class or meeting. Either way, the activity provides a way to get people talking while the participants simultaneously learn something new and …


Gravitational Waves: New Observatories For New Astronomy, Louis J. Rubbo, Shane L. Larson, Michelle B. Larson, Kristina D. Zaleski Jan 2006

Gravitational Waves: New Observatories For New Astronomy, Louis J. Rubbo, Shane L. Larson, Michelle B. Larson, Kristina D. Zaleski

All Physics Faculty Publications

This article reviews the current status of gravitational wave astronomy and explains why astronomers are excited about the new generation of gravitational wave detectors. As part of the review we compare and contrast gravitational radiation to the more familiar electromagnetic radiation. We discuss the current indirect experimental evidence for gravitational waves and how current and future gravitational wave detectors will operate as our newest telescopes are pointed at the skies.