Search Publications
Missions
Journals
Publication Years
Warm and cool starspots with opposite polarities. A high-resolution Zeeman-Doppler-Imaging study of II Pegasi with PEPSI
Strassmeier, K. G.; Carroll, T. A.; Ilyin, I. V.
Aims: We present a temperature and a magnetic-field surface map of the K2 subgiant of the active binary II Peg. Employed are high resolution Stokes IV spectra obtained with the new Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT).
Methods: Fourteen average line profiles are inverted…
The First Direct Observational Confirmation of Kinematic Collisionless Relaxation in Very Low Mach Number Shocks Near the Earth
Balikhin, M. A.; Gedalin, M.; Pope, S. A.
Collisionless shocks are ubiquitous throughout the known universe. They mainly convert the energy of the directed ion flow into heating. Upon crossing the shock front, the ion distribution becomes nongyrotropic. Relaxation to gyrotropy then occurs mainly via kinematic collisionless gyrophase mixing and interaction with waves. The theory of collisi…
Light element variations within the different age-metallicity populations in the nucleus of the Sagittarius dwarf
Cadelano, Mario; Dalessandro, Emanuele; Sills, Alison +2 more
The cluster M54 lies at the centre of the Sagittarius dwarf spheroidal galaxy, and therefore may be the closest example of a nuclear star cluster. Either in situ star formation, inspiralling globular clusters, or a combination have been invoked to explain the wide variety of stellar sub-populations in nuclear star clusters. Globular clusters are k…
The 2018 Martian Global Dust Storm Over the South Polar Region Studied With MEx/VMC
Hueso, R.; Sánchez-Lavega, A.; Titov, D. +6 more
We study the 2018 Martian global dust storm (GDS 2018) over the Southern Polar Region using images obtained by the Visual Monitoring Camera (VMC) on board Mars Express (MEx) during June and July 2018. Dust penetrated into the polar cap region but never covered the cap completely, and its spatial distribution was nonhomogeneous and rapidly changing…
A comparison between solar plage and network properties
Solanki, S. K.; Lagg, A.; van Noort, M. +1 more
Aims: We compare the properties of kG magnetic structures in the solar network and in active region plage at high spatial resolution.
Methods: Our analysis used six SP scans of the solar disc centre aboard Hinode SOT and inverted the obtained spectra of the photospheric 6302 Å line pair using the 2D SPINOR code.
Results: Photospheri…
Image simulations for gravitational lensing with SKYLENS
Plazas, A. A.; Meneghetti, M.; Rhodes, J. +1 more
We present the latest version of the ray-tracing simulation code SKYLENS, which can be used to develop image simulations that reproduce strong lensing observations by any mass distribution with a high level of realism. Improvements of the code with respect to previous versions include the implementation of the multilens plane formalism, the use of…
Two kinematically distinct old globular cluster populations in the Large Magellanic Cloud
Piatti, Andrés E.; Cantat-Gaudin, Tristan; Alfaro, Emilio J.
We report results of proper motions of 15 known Large Magellanic Cloud (LMC) old globular clusters (GCs) derived from the Gaia DR2 data sets. When these mean proper motions are gathered with existent radial velocity measurements to compose the GCs' velocity vectors, we found that the projection of the velocity vectors on to the LMC plane and those…
Unusual Isotopic Abundances in a Fully Convective Stellar Binary
Mills, E. A. C.; Crossfield, I. J. M.; Lothringer, J. D. +6 more
Low-mass M dwarfs represent the most common outcome of star formation, but their complex emergent spectra hinder detailed studies of their composition and initial formation. The measurement of isotopic ratios is a key tool that has been used to unlock the formation of our solar system, the Sun, and the nuclear processes within more massive stars. …
The Duration of Star Formation in Galactic Giant Molecular Clouds. I. The Great Nebula in Carina
Povich, Matthew S.; Nuñez, Evan Haze; Robitaille, Thomas P. +1 more
We present a novel infrared spectral energy distribution (SED) modeling methodology that uses likelihood-based weighting of the model fitting results to construct probabilistic Hertzsprung-Russell diagrams (pHRD) for X-ray-identified, intermediate-mass (2-8 M ⊙), pre-main-sequence young stellar populations. This methodology is designed …
The Lomonosov Crater Impact Event: A Possible Mega-Tsunami Source on Mars
Bouley, S.; Séjourné, A.; Lagain, A. +6 more
Recent research suggests that major meteorite impact events into a Late Hesperian/Early Amazonian ocean likely produced a mega-tsunami that would have resurfaced coastal areas in northwestern Arabia Terra. The orientations of the associated lobate deposits, a conspicuous type of landforms called Thumbprint Terrain, suggests that if an impact event…