We investigate the orientation of the axes and angular momentum of dark matter halos with respect to their neighboring voids using high-resolution N-body cosmological simulations. We find that the minor axis of a halo tends to be aligned along the line joining the halo with the center of the void and that the major axis tends to lie in the plane

A large set of high-precision, full-Stokes spectro-polarimetric observations of prominences in He I D3, Hα, and Hβ lines has been recorded with the ZIMPOL polarimeter at the Gregory-Coudé Telescope in Locarno. The observational technique allows us to obtain measurements free from seeing-induced spurious effects. The instrumental polarization is

Recordings of the full Stokes vector of filaments in the Hα and He I D3 lines were obtained at the Gregory-Coudé telescope in Locarno with the polarimeter ZIMPOL. The aim was to perform preliminary studies to explore the presence of forward scattering polarization. The observations show linear polarization signatures, whose interpretation is still

We present a study of two spectral lines, Fe I 6173 Å and Ni I 6768 Å, that were candidates to be used in the Helioseismic and Magnetic Imager (HMI) for observing Doppler velocity and the vector magnetic field. The line profiles were studied using the Mt. Wilson Observatory, the Advanced Stokes Polarimeter and the Kitt Peak-McMath Pierce telescope

We present information on two spectral lines, Fe I 6173 Å and Ni I 6768 Å, that were candidates for use in the Helioseismic and Magnetic Imager (HMI) instrument. Both Fe I and Ni I profiles have clean continuum and no blends that threaten performance. The higher Landé factor of Fe I means its operational velocity range in regions of strong magnetic

A long-debated issue concerning the nucleosynthesis of neutron-rich elements in asymptotic giant branch (AGB) stars is the identification of the neutron source. We report intermediate-mass (4 to 8 solar masses) AGB stars in our Galaxy that are rubidium-rich as a result of overproduction of the long-lived radioactive isotope 87Rb, as predicted