Physical Sciences and Mathematics | Open Access Articles

Evidence For Electron Energization Accompanying Spontaneous Formation Of Ion Acceleration Regions In Expanding Plasmas, Evan M. Aguirre, Rikard Bodin, Neng Yin, Timothy N. Good, Earl E. Scime

Physics and Astronomy Faculty Publications

We report experiments conducted in an expanding argon plasma generated in the inductive mode of a helicon source in the Hot hELIcon eXperiment–Large Experiment on Instabilities and Anisotropies facility. As the neutral gas pressure increases, the supersonic ion acceleration weakens. Increasing neutral pressure also alters the radial profile of electron temperature, density, and plasma potential upstream of the plasma expansion region. Langmuir probe measurements of the electron energy probability function (EEPF) show that heating of electrons at the plasma edge by RF fields diminishes with increasing gas pressure, yielding a plasma with a centrally peaked electron temperature, and flat potential …

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Space Telescope And Optical Reverberation Mapping Project. Xi. Disk-Wind Characteristics And Contributions To The Very Broad Emission Lines Of Ngc 5548, Maryam Dehghanian, Gary J. Ferland, G. A. Kriss, B. M. Peterson, K. T. Korista, M. R. Goad, Marios Chatzikos, Francisco Guzmán, G. De Rosa, M. Mehdipour, J. Kaastra, S. Mathur, M. Vestergaard, D. Proga, T. Waters, M. C. Bentz, S. Bisogni, W. N. Brandt, E. Dalla Bontà, M. M. Fausnaugh, J. M. Gelbord, Keith Horne, I. M. Mchardy, R. W. Pogge, D. A. Starkey

Physics and Astronomy Faculty Publications

In 2014 the NGC 5548 Space Telescope and Optical Reverberation Mapping campaign discovered a two-month anomaly when variations in the absorption and emission lines decorrelated from continuum variations. During this time the soft X-ray part of the intrinsic spectrum had been strongly absorbed by a line-of-sight (LOS) obscurer, which was interpreted as the upper part of a disk wind. Our first paper showed that changes in the LOS obscurer produces the decorrelation between the absorption lines and the continuum. A second study showed that the base of the wind shields the broad emission-line region (BLR), leading to the emission-line decorrelation. …

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Vla Imaging Of H I-Bearing Ultra-Diffuse Galaxies From The Alfalfa Survey, Lexi Gault, Lukas Leisman, Elizabeth A.K. Adams, Pavel E. Mancera Piña, Kameron Reiter, Nicholas Smith, Michael Battipaglia, John M. Cannon, Filippo Fraternali, Martha P. Haynes, Elizabeth Mcallan, Hannah J. Pagel, Katherine L. Rhode, John J. Salzer, Quinton Singer

Physics and Astronomy Faculty Publications

Ultra-diffuse galaxies have generated significant interest due to their large optical extents and low optical surface brightnesses, which challenge galaxy formation models. Here we present resolved synthesis observations of 12 H i-bearing ultra-diffuse galaxies (HUDs) from the Karl G. Jansky Very Large Array (VLA), as well as deep optical imaging from the WIYN 3.5-meter telescope at Kitt Peak National Observatory. We present the data processing and images, including total intensity H i maps and H i velocity fields. The HUDs show ordered gas distributions and evidence of rotation, important prerequisites for the detailed kinematic models in Mancera Pi˜na et al. …

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Full-Text Articles in Physical Sciences and Mathematics

Evidence For Electron Energization Accompanying Spontaneous Formation Of Ion Acceleration Regions In Expanding Plasmas, Evan M. Aguirre, Rikard Bodin, Neng Yin, Timothy N. Good, Earl E. Scime

Physics and Astronomy Faculty Publications

Physics and Astronomy Faculty Publications

Physics and Astronomy Faculty Publications