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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

2000

Expansion

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Plasma Oscillations And Expansion Of An Ultracold Neutral Plasma, Scott D. Bergeson, S. Kulin, T. C. Killian, S. L. Rolston Jul 2000

Plasma Oscillations And Expansion Of An Ultracold Neutral Plasma, Scott D. Bergeson, S. Kulin, T. C. Killian, S. L. Rolston

Faculty Publications

We report the observation of plasma oscillations in an ultracold neutral plasma. With this collective mode we probe the electron density distribution and study the expansion of the plasma as a function of time. For classical plasma conditions, i.e., weak Coulomb coupling, the expansion is dominated by the pressure of the electron gas and is described by a hydrodynamic model. Discrepancies between the model and observations at low temperature and high density may be due to strong coupling of the electrons.


Detection Of Co And Dust Emission In Near-Infrared Spectra Of Sn 1998s, Christopher L. Gerardy, Robert A. Fesen, Peter Höflich, J. Craig Wheeler Jan 2000

Detection Of Co And Dust Emission In Near-Infrared Spectra Of Sn 1998s, Christopher L. Gerardy, Robert A. Fesen, Peter Höflich, J. Craig Wheeler

Dartmouth Scholarship

Near-infrared spectra (0.95 – 2.4 μ m) of the peculiar Type IIn supernova 1998S in NGC 3877 from 95 to 355 days after maximum light are presented. K -band data taken at days 95 and 225 show the presence of the first overtone of CO emission near 2.3 μ m, which is gone by day 355. An apparent extended blue wing on the CO profile in the day 95 spectrum could indicate a large CO expansion velocity (≈ 2000 – 3000 km s − 1). This is the third detection of infrared CO emission in nearly as many Type II …