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Full-Text Articles in Physical Sciences and Mathematics

Pfisr Nightside Observations Of Naturally Enhanced Ion Acoustic Lines, And Their Relation To Boundary Auroral Features, R. G. Michell, K. A. Lynch, C. J. Heinselman, H. C. Stenbaek-Nielsen Nov 2008

Pfisr Nightside Observations Of Naturally Enhanced Ion Acoustic Lines, And Their Relation To Boundary Auroral Features, R. G. Michell, K. A. Lynch, C. J. Heinselman, H. C. Stenbaek-Nielsen

Dartmouth Scholarship

We present results from a coordinated camera and radar study of the auroral ionosphere conducted during March of 2006 from Poker Flat, Alaska. The campaign was conducted to coincide with engineering tests of the first quarter installation of the Poker Flat Incoherent Scatter Radar (PFISR). On 31 March 2006, a moderately intense auroral arc, (~10 kR at 557.7 nm), was located in the local magnetic zenith at Poker Flat. During this event the radar observed 7 distinct periods of abnormally large backscattered power from the F-region. These were only observed in the field-aligned radar beam, and radar spectra from these …


Ages And Metallicities Of Early-Type Void Galaxies From Line Strength Measurements, Gary Wegner, Norman A. Grogin May 2008

Ages And Metallicities Of Early-Type Void Galaxies From Line Strength Measurements, Gary Wegner, Norman A. Grogin

Dartmouth Scholarship

We present spectroscopic observations of 26 galaxies of type E and S0, based on their blue morphologies, located in voids by the study of Grogin & Geller in 1999. Measurements of redshift, velocity dispersion, and four Lick line indices, Mg b , Fe5270, Fe5335, and Hβ with their errors are given for all of these galaxies, along with Hβ, [O III], Hα, and [N II] emission line strengths for a subset of these objects. These sources are brighter than M* for low-density regions and tend to be bluer than their counterpart early-type objects in high-density regions. Using the models …