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Articles 1 - 15 of 15
Full-Text Articles in Entire DC Network
The X-Ray Variability Of Seyfert Galaxies, Kevin Marshall
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 …
1021-0304_Mir_Irs, Michael C. Cushing
Book Review: Evolution Of Stars And Stellar Populations, T. D. Oswalt
Book Review: Evolution Of Stars And Stellar Populations, T. D. Oswalt
Publications
This document is Dr. Oswalt’s review of Evolution of Stars and Stellar Populations by Maurizio Salaris and Santi Cassisi Wiley, 2005 374p, 047009219X $150.00, 047009219X $60.00
Abstracts Of Papers, 84th Annual Meeting Of The Virginia Academy Of Science
Abstracts Of Papers, 84th Annual Meeting Of The Virginia Academy Of Science
Virginia Journal of Science
Full abstracts of papers for the 84th Annual Meeting of the Virginia Academy of Science, May 25-26, 2006, Virginia Polytechnic Institute and State University, Blacksburg, VA
Stargazing: Observatories At Gettysburg College, 1874-Present, Andrew A. Carlson
Stargazing: Observatories At Gettysburg College, 1874-Present, Andrew A. Carlson
Hidden in Plain Sight Projects
Astronomy has long been a subject which has attracted the interest of man. Examples of early astronomers can be found in many ancient civilizations, including but not limited to, the Egyptians, the Chinese and the Greeks. As time passed the methods for interpreting the stars and theories that surrounded them changed concordant with the technology available. One of the largest breakthroughs in the world of astronomy was the invention of the telescope in the early seventeenth century. Often mis-attributed to Galileo (who was responsible for building the first reflecting telescope in 1688), the telescope was actually first designed by a …
An Astronomical Account: A History Of Hatter Planetarium From 1966-2006, Jonathan D. Neu
An Astronomical Account: A History Of Hatter Planetarium From 1966-2006, Jonathan D. Neu
Hidden in Plain Sight Projects
When most individuals stare up at the vast dome of Hatter Planetarium, they often gaze upon the projected stars appearing on its surface, listening to an astronomical story told by one of its operators. However, there is a second story told by the planetarium itself. This story is the history of Hatter Planetarium, which spans five decades and includes the events in the lives of several individuals who have played a critical role in its existence at Gettysburg College. Its history has encompassed several phases of Gettysburg College traditions but is in danger of passing permanently and fixedly into the …
Astronomy And Music, Weien Wang
Book Review: Fred Hoyle's Universe, T. D. Oswalt
Book Review: Fred Hoyle's Universe, T. D. Oswalt
Publications
This document is Dr. Oswalt’s review of Fred Hoyle's Universe by Jane Gregory. Oxford, 2005 406p, 0198507917 $29.95
"Encyclopedia Of Space And Astronomy" Book Review, Skye Hardesty
"Encyclopedia Of Space And Astronomy" Book Review, Skye Hardesty
University Library Faculty Publications
This is a review of the Encyclopedia of Space and Astronomy.
Crater Gradation In Gusev Crater And Meridiani Planum, Mars, J. A. Grant, Raymond E. Arvidson, L. S. Crumpler, Matt P. Golombek, B. Hahn, A. F.C. Haldemann, Rongxing Li, L. A. Soderblom, Steven W. Squyres, S. P. Wright, Wesley Andres Watters
Crater Gradation In Gusev Crater And Meridiani Planum, Mars, J. A. Grant, Raymond E. Arvidson, L. S. Crumpler, Matt P. Golombek, B. Hahn, A. F.C. Haldemann, Rongxing Li, L. A. Soderblom, Steven W. Squyres, S. P. Wright, Wesley Andres Watters
Faculty Research and Scholarship
The Mars Exploration Rovers investigated numerous craters in Gusev crater and Meridiani Planum during the first ∼400 sols of their missions. Craters vary in size and preservation state but are mostly due to secondary impacts at Gusev and primary impacts at Meridiani. Craters at both locations are modified primarily by eolian erosion and infilling and lack evidence for modification by aqueous processes. Effects of gradation on crater form are dependent on size, local lithology, slopes, and availability of mobile sediments. At Gusev, impacts into basaltic rubble create shallow craters and ejecta composed of resistant rocks. Ejecta initially experience eolian stripping, …
Spatial Grain Size Sorting In Eolian Ripples And Estimation Of Wind Conditions On Planetary Surfaces: Application To Meridiani Planum, Mars, Douglas J. Jerolmack, David Mohrig, John P. Grotzinger, David A. Fike, Wesley Andres Watters
Spatial Grain Size Sorting In Eolian Ripples And Estimation Of Wind Conditions On Planetary Surfaces: Application To Meridiani Planum, Mars, Douglas J. Jerolmack, David Mohrig, John P. Grotzinger, David A. Fike, Wesley Andres Watters
Faculty Research and Scholarship
The landscape seen by the Mars Exploration Rover (MER) Opportunity at Meridiani Planum is dominated by eolian (wind-blown) ripples with concentrated surface lags of hematitic spherules and fragments. These ripples exhibit profound spatial grain size sorting, with well-sorted coarse-grained crests and poorly sorted, generally finer-grained troughs. These ripples were the most common bed form encountered by Opportunity in its traverse from Eagle Crater to Endurance Crater. Field measurements from White Sands National Monument, New Mexico, show that such coarse-grained ripples form by the different transport modes of coarse- and fine-grain fractions. On the basis of our field study, and simple …
Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne
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 …
Gravitational Waves: New Observatories For New Astronomy, Louis J. Rubbo, Shane L. Larson, Michelle B. Larson, Kristina D. Zaleski
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.
Science Icebreaker Activities: An Example From Gravitational Wave Astronomy, Michelle B. Larson, Louis J. Rubbo, Kristina D. Zaleski, Shane L. Larson
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 …
Book Review: The Amateur Astronomer's Introduction To The Celestial Sphere, T. D. Oswalt
Book Review: The Amateur Astronomer's Introduction To The Celestial Sphere, T. D. Oswalt
Publications
This document is Dr. Oswalt’s review of The Amateur Astronomer's Introduction to the Celestial Sphere by William Millar. Cambridge, 2006 299p, 052167123X $40.00, 9780521671231 $40.00.