On the basis of NLTE profile calculations obtained by employing the radiative transfer code MULTI, the influence of the uncertainties of various parameters important in the formation of the photospheric Mn I 539.4 nm spectral line are discussed. Two cases are separately considered: with and without energy transfer between Mg II and Mn I. All

Not Available

We study a neutrino gas in equilibrium both at T = 0 and at finite temperature. The neutrinos are assumed to be massive Dirac particles with two generations interacting with each other via neutral currents and with a background of matter. We analyze the main properties of the neutrino eigenmodes in the medium, such as effective masses and mixing

We studied the SB0 galaxy NGC 2950, which hosts two nested stellar bars. We used the Tremaine-Weinberg method to measure the pattern speed of the primary bar. We established directly and for the first time in a double-barred galaxy that the two nested bars are rotating with different pattern speeds.

We have searched for shock-excited molecular hydrogen knots in five selected areas of the Chamaeleon I dark cloud using narrow-band images centered on the H_2 line and neighboring continuum. In the northern part of the cloud (Cha IN), we found seven new H_2 knots, five of which are aligned in the direction of a previously known CO molecular bipolar

We present a detailed and uniform study of oxygen abundances in a large set of 155 metal-rich dwarfs. EW measurements were carried out for the [OI] 6300 Å line and the OI triplet, while spectral synthesis was performed for several OH lines. NLTE corrections were calculated and applied to the LTE abundance results derived from the triplet