G. C. Cortright, Jr. testimony

Testimony of G. C. Cortright, Jr. of Sharkey County, Mississippi concerning agricultural matters before the U.S. Senate Committee on Agriculture and Forestry. 1955https://scholarsjunction.msstate.edu/mss-stevens-papers/1078/thumbnail.jp

Geologic and Hydrologic Effects of a Catastrophic Flood in the Cold River, Southwestern New Hampshire

Guidebook for field trips in Vermont: New England Intercollegiate Geological Conference, 79th annual meeting, October 16, 17 and 18, 1987: Trips A-2; C-

The Circumstellar Extinction of Planetary Nebulae

We analyze the dependence of circumstellar extinction on core mass for the brightest planetary nebulae (PNe) in the Magellanic Clouds and M31. We show that in all three galaxies, a statistically significant correlation exists between the two quantities, such that high core mass objects have greater extinction. We model this behavior, and show that the relation is a simple consequence of the greater mass loss and faster evolution times of high mass stars. The relation is important because it provides a natural explanation for the invariance of the [O III] 5007 planetary nebula luminosity function (PNLF) with population age: bright Population I PNe are extinguished below the cutoff of the PNLF. It also explains the counter-intuitive observation that intrinsically luminous Population I PNe often appear fainter than PNe from older, low-mass progenitors.Comment: 12 pages, 2 figures, accepted for ApJ, April 10, 199

Joint Publications Research Service Translations

published or submitted for publicatio

Pulsars and Gravitational Wave Detection

The number of known millisecond pulsars has dramatically increased in the last few years. Regular observations of these pulsars may allow gravitational waves with frequencies ~10^-9 Hz to be detected. A ``pulsar timing array'' is therefore complimentary to other searches for gravitational waves using ground-based or space-based interferometers that are sensitive to much higher frequencies. In this review we describe 1) the basic methods for using an array of pulsars as a gravitational wave detector, 2) the sources of the potentially detectable waves, 3) current limits on individual sources and a stochastic background and 4) the new project recently started using the Parkes radio telescope.Comment: Accepted by PAS