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The Optical Wind Line Variability of η Carinae During the 2009.0 Event
Gull, T. R.; Gies, D. R.; Richardson, N. D. +2 more
We report on high-resolution spectroscopy of the 2009.0 spectroscopic event of η Carinae collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two-month interval around the photometric minimum of η Car associated with the periastron passage of a hot companion…
Distant ionospheric photoelectron energy peak observations at Venus
Coates, A. J.; Fedorov, A.; Barabash, S. +4 more
The dayside of the Venus ionosphere at the top of the planet's thick atmosphere is sustained by photoionization. The consequent photoelectrons may be identified by specific peaks in the energy spectrum at 20-30 eV which are mainly due to atomic oxygen photoionization. The ASPERA-4 electron spectrometer has an energy resolution designed to identify…
Seed Population in Large Solar Energetic Particle Events and the Twin-CME Scenario
Li, Gang; Ding, Liu-Guan; Le, Gui-Ming +2 more
It has recently been suggested that large solar energetic particle (SEP) events are often caused by twin coronal mass ejections (CMEs). In the twin-CME scenario, the preceding CME provides both an enhanced turbulence level and enhanced seed population at the main CME-driven shock. In this work, we study the effect of the preceding CMEs on the seed…
Survey of Saturn Z-mode emission
Gurnett, D. A.; Persoon, A. M.; Wahlund, J. -E. +6 more
Because of the role of Z-mode emission in the diffusive scattering and resonant acceleration of electrons, we conduct a survey of intensity in the Saturn inner magnetosphere. Z mode is primarily observed as "5 kHz" narrowband emission in the lower density regions where the ratio of cyclotron to plasma frequency, fc/fp > 1 …
An Extreme High-velocity Bipolar Outflow in the Pre-planetary Nebula IRAS 08005-2356
Sahai, R.; Patel, N. A.
We report interferometric mapping of the bipolar pre-planetary nebula IRAS 08005-2356 (I 08005) with an angular resolution of ∼1″-5″, using the Submillimeter Array, in the 12CO J = 2-1, 3-2, 13CO J = 2-1, and SiO J = 5-4 (v = 0) lines. Single-dish observations, using the SMT 10 m, were made in these lines as well as in the CO…
Near-infrared Extinction due to Cool Supernova Dust in Cassiopeia A
Koo, Bon-Chul; Lee, Jae-Joon; Moon, Dae-Sik +1 more
We present the results of extinction measurements toward the main ejecta shell of the Cassiopeia A supernova (SN) remnant using the flux ratios between the two near-infrared (NIR) [Fe ii] lines at 1.26 and 1.64 µm. We find a clear correlation between the NIR extinction (E(J-H)) and the radial velocity of ejecta knots, showing that redshifted…
Evolution of the central stars of young planetary nebulae
Zijlstra, A. A.; van Hoof, P. A. M.; Hajduk, M.
Aims: The evolution of central stars of planetary nebulae was so far documented in just a few cases. However, spectra collected a few decades ago may provide a good reference for studying the evolution of central stars using the emission line fluxes of their nebulae. We investigated evolutionary changes of the [O iii] 5007 Å line flux in the …
Magnetic balltracking: Tracking the photospheric magnetic flux
Innes, D. E.; Attie, R.
Context. One aspect of understanding the dynamics of the quiet Sun is to quantify the evolution of the flux within small-scale magnetic features. These features are routinely observed in the quiet photosphere and were given various names, such as pores, knots, magnetic patches.
Aims: This work presents a new algorithm for tracking the evoluti…
Molecular nitrogen and methane density retrievals from Cassini UVIS dayglow observations of Titan's upper atmosphere
Esposito, Larry W.; Bradley, E. Todd; Ajello, Joseph M. +4 more
We retrieve number densities of molecular nitrogen (N2) and methane (CH4) from Titan's upper atmosphere using the UV dayglow. We use Cassini Ultraviolet Imaging Spectrograph (UVIS) limb observations from 800 to 1300 km of the N I 1493 Å and N II 1085 Å multiplets, both produced directly from photofragmentation of N2
Mid-J CO shock tracing observations of infrared dark clouds. I.
Johnstone, D.; Caselli, P.; Jiménez-Serra, I. +5 more
Infrared dark clouds (IRDCs) are dense, molecular structures in the interstellar medium that can harbour sites of high-mass star formation. IRDCs contain supersonic turbulence, which is expected to generate shocks that locally heat pockets of gas within the clouds. We present observations of the CO J = 8-7, 9-8, and 10-9 transitions, taken with th…