Search Publications
A wind-shell interaction model for multipolar planetary nebulae
López, J. A.; Steffen, W.; Koning, N. +4 more
We explore the formation of multipolar structures in planetary and pre-planetary nebulae from the interaction of a fast post-asymptotic giant branch wind with a highly inhomogeneous and filamentary shell structure assumed to form during the final phase of the high-density wind. The simulations were performed with a new hydrodynamics code integrate…
De-excitation Nuclear Gamma-Ray Line Emission from Low-energy Cosmic Rays in the Inner Galaxy
Strong, A. W.; Kiener, J.; Tatischeff, V. +1 more
Recent observations of high ionization rates of molecular hydrogen in diffuse interstellar clouds point to a distinct low-energy cosmic-ray component. Supposing that this component is made of nuclei, two models for the origin of such particles are explored and low-energy cosmic-ray spectra are calculated, which, added to the standard cosmic-ray sp…
Improved calibration of SOIR/Venus Express spectra
Bertaux, Jean-Loup; Belyaev, Denis; Vandaele, Ann Carine +10 more
Rotation Rates of Coronal Holes and their Probable Anchoring Depths
Hegde, M.; Hiremath, K. M.
From 2001-2008, we use full-disk, SOHO/EIT 195 Å calibrated images to determine latitudinal and day-to-day variations of the rotation rates of coronal holes (CHs). We estimate the weighted average of heliographic coordinates such as latitude and longitude from the central meridian on the observed solar disk. For different latitude zones between 40…
XMM-Newton Monitoring of the Close Pre-main-sequence Binary AK Sco. Evidence of Tide-driven Filling of the Inner Gap in the Circumbinary Disk
Gómez de Castro, Ana I.; Talavera, Antonio; Bisikalo, D. +2 more
AK Sco stands out among pre-main-sequence binaries because of its prominent ultraviolet excess, the high eccentricity of its orbit, and the strong tides driven by it. AK Sco consists of two F5-type stars that get as close as 11 R * at periastron passage. The presence of a dense (ne ~ 1011 cm-3) extended …
Correlation of spectral solar irradiance with solar activity as measured by VIRGO
Schmutz, W.; Shapiro, A. I.; Wehrli, C.
Context. The variability of solar spectral irradiance (SSI) over the rotational period and its trend over the solar activity cycle are important for understanding the Sun-Earth connection as well as for observational constraints for solar models. Recently the Spectral Irradiance Monitor (SIM) experiment on the Solar Radiation and Climate Experimen…
Evolutionary paths among different red galaxy types at 0.3 < z < 1.5 and the late buildup of massive E-S0s through major mergers
Barro, Guillermo; Pérez-González, Pablo G.; Eliche-Moral, M. Carmen +11 more
Some recent observations seem to disagree with hierarchical theories of galaxy formation about the role played by major mergers in the late buildup of massive E-S0s. We re-address this question by analysing the morphology, structural distortion level and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010
Constraints on Porosity and Mass Loss in O-star Winds from the Modeling of X-Ray Emission Line Profile Shapes
Leutenegger, Maurice A.; Cohen, David H.; Sundqvist, Jon O. +1 more
We fit X-ray emission line profiles in high resolution XMM-Newton and Chandra grating spectra of the early O supergiant ζ Pup with models that include the effects of porosity in the stellar wind. We explore the effects of porosity due to both spherical and flattened clumps. We find that porosity models with flattened clumps oriented parallel to th…
Signatures of magnetospheric injections in Saturn's aurora
Krupp, N.; Roussos, E.; Mitchell, D. G. +6 more
We report on the evolution of auroral structures based on two 3 h sequences of Saturn's northern hemisphere obtained with the UVIS instrument on board Cassini, and we discuss their possible association with injections in the magnetosphere of Saturn. Simultaneously with the UV auroral structures, we observe Energetic Neutral Atom (ENA) enhancements…
A Survey of Infrared Supernova Remnants in the Large Magellanic Cloud
Onaka, Takashi; Seok, Ji Yeon; Koo, Bon-Chul
We present a comprehensive infrared study of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) using near- to mid-infrared images taken by Infrared Array Camera (IRAC; 3.6, 4.5, 5.8, and 8 µm) and Multiband Imaging Photometer (MIPS; 24 and 70 µm) onboard the Spitzer Space Telescope. Among the 47 bona fide LMC SNRs, 29 were …