Long-slit observations of the blue compact galaxy Haro 2 have been performed around Hα and Hβ. The main aim of these observations was to detect the Hα emission originating in the partially ionized wind outflow-ing at 200 km/s, that had been previously detected with the Hubble Space Telescope (HST). A shallow broadening of the Hα line wings has been observed, consistent with the existence of an ...

The Europa Clipper is a NASA mission concept to study Europa, the ice-covered moon of Jupiter, though a series of fly-by observations of the Europan surface and subsurface from a spacecraft in Jovian orbit. One of the primary instruments in the strawman scientific payload is a multifrequency, multi-channel ice penetrating radar (IPR) system. The IPR will play a critical role in achieving the mi...

Future Europa exploration will seek to characterize the distribution of shallow subsurface water as well as to understand the formation of surface features through dynamic ice-shell processes. Radar sounding will be a critical tool for detecting these features, and should be of primary interest to the astrobiology community for understanding how and where life might arise on Europa. To develop ...

The positioning of a bubble inside a many fermion system does not affect the volume, surface, or curvature terms in the liquid drop expansion of the total energy. Besides possible Coulomb effects, the only other contribution to the ground state energy of such a system arises from shell effects. We show that the potential energy surface is a rather shallow function of the displacement of the bub...

In this paper we obtain a limit model for a turbine blade fixed to a 3D solid. This model is a three-dimensional linear elasticity problem in the 3D part of the piece (the rotor) and a two-dimensional problem (the nonlinear shallow shell equations) in the 2D part (the turbine blade), with junction conditions in the part of the turbine blade fixed to the rotor. To obtain this model, we perform a...

The present study is concerned with thin isotropic shallow shells interacting with inviscid fluid flow of constant velocity. It is assumed that the dynamic behaviour of the shells is governed by the Marguerre–von Kármán equations. The influence of the fluid flow is taken into account by introducing additional differential and external load terms in the shell equations. It is shown that the syst...

A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species Pleurolucina leucocyma, it is most similar to the eastern Pacific Pleurolucina undata. As in all studied lucinids, the new species po...

Unique new fossil assemblages containing the large bivalve family Alatoconchidae are recorded from the Guadalupian (Middle Permian) shallow marine limestone in Kamura, Kyushu. The large bivalves occur in the Neoschwagerina Zone and Lepidolina Zone. This discovery establishes that the biostratigraphic range of the family Alatoconchidae extends up to the top of the Lepidolina Zone (upper Capitani...