Search Publications
Determining the orbital parameters of binary systems with an AGB primary. The case of the R Aqr symbiotic system
Alcolea, J.; Bachiller, R.; Santander-García, M. +6 more
Binary stars including an AGB star hold the clues for understanding important phenomena in stellar evolution, such as common-envelope events, the formation of SN-Ia, and the origin of aspherical pPNe/PNe. Hydro-dynamical codes simulating the companion's influence on the primary mass loss exist, but we still lack information on the orbital paramete…
The multichord stellar occultation by the centaur Bienor on January 11, 2019
Colas, F.; Mottola, S.; Souami, D. +42 more
Within our program of physical characterization of trans-Neptunian objects and centaurs, we predicted a stellar occultation by the centaur (54598) Bienor to occur on January 11, 2019, with good observability potential. We obtained high accuracy astrometric data to refine the prediction, resulting in a shadow path favorable for the Iberian Peninsul…
A Hunting Expedition For High-Order Hierarchies
Kostov, Veselin B.; Powell, Brian P.; Tokovinin, Andrei
Stellar hierarchical systems of high order containing more than three stars are rare and fascinating objects; their discovery and study highlight still unknown aspects of star formation and early evolution. We matched eclipsing binaries discovered by Transiting Exoplanet Survey Satellite with a Gaia catalogue of wide binaries and selected candidat…
Data-Based Modeling of the Magnetosheath Magnetic Field
Semenov, V. S.; Erkaev, N. V.; Tsyganenko, N. A.
A quantitative model of the magnetosheath (MS) magnetic structure is developed, using a multi-year set of Geotail, Themis, Cluster, and MMS magnetometer and plasma instrument data. The MS database is created using an identification algorithm, based on observed magnetic field magnitudes and proton densities, normalized by their concurrent interplan…
The morphology of exciting dark matter and the galactic 511 keV signal
Vincent, Aaron C.; Cappiello, Christopher V.; Jafs, Michael
We study the morphology of the 511 keV signal that could be produced by exciting dark matter (XDM) in the Milky Way. In this model, collisions between dark matter particles excite the dark matter to a state that can then decay back to the ground state, releasing an electron-positron pair. These electrons and positrons would then annihilate, produc…
Minor species in Venus' night side troposphere as observed by VIRTIS-H/Venus Express
Robert, S.; Montmessin, F.; Bertaux, J. -L. +10 more
The 2 . 3 µm spectral window has been used to constrain the composition of the lower atmosphere (in the 30-40 km altitude range) on the night side of Venus for more than thirty years. Here, we present a follow-up study of Marcq et al. (2008), but using the full VIRTIS-H/Venus Express data archive as well as an updated radiative transfer forw…
Exotic image formation in strong gravitational lensing by clusters of galaxies - IV. Elliptical NFW lenses and hyperbolic umbilics
Meena, Ashish Kumar; Bagla, Jasjeet Singh
A source lying near a hyperbolic umbilic (HU) singularity leads to a ring-like image formation, constituting four images with high magnification factors and lying in a small region of the lens plane. Since (based on our earlier work) the observed number of HU image formations in cluster lenses is expected to increase in the future, it is timely to…
SPT-CL J2215-3537: A Massive Starburst at the Center of the Most Distant Relaxed Galaxy Cluster
Mahler, Guillaume; Allen, Steven W.; Sharon, Keren +15 more
We present the discovery of the most distant, dynamically relaxed cool core cluster, SPT-CL J2215-3537 (SPT2215), and its central brightest cluster galaxy (BCG) at z = 1.16. Using new X-ray observations, we demonstrate that SPT2215 harbors a strong cool core with a central cooling time of 200 Myr (at 10 kpc) and a maximal intracluster medium cooli…
The imprint of bursty star formation on alpha-element abundance patterns in Milky Way-like galaxies
Bailin, Jeremy; Stern, Jonathan; Faucher-Giguère, Claude-André +5 more
Milky Way-mass galaxies in the FIRE-2 simulations demonstrate two main modes of star formation. At high redshifts star formation occurs in a series of short and intense bursts, while at low redshifts star formation proceeds at a steady rate with a transition from one mode to another at times ranging from 3 to 7 Gyr ago for different galaxies. We a…
Undulated Shock Surface Formed After a Shock-Discontinuity Interaction
Shen, Chao; Zhou, Yufei; Ji, Yong
Shock ripples and shock-discontinuity interactions (SDIs) have long been proposed to explain the frequent occurrence of high-speed jets (HSJs) in the magnetosheath; however, there is no direct observational evidence for either of them occurring near a shock. Herein, we report a large-scale, long-duration undulated quasi-perpendicular shock surface…