The properties of 322 intermediate-mass late-G giants (comprising 10 planet-host stars) selected as the targets of the Okayama Planet Search Program, many of which are red-clump giants, were comprehensively investigated by establishing their various stellar parameters (atmospheric parameters, including turbulent velocity fields, metallicity, luminosity, mass, age, projected rotational velocity, etc.), and their photospheric chemical abundances for 17 elements, in order to study their mutual dependence, connection with the existence of planets, and possible evolution-related characteristics. The metallicity distribution of planet-host giants was found to be almost the same as that of non-planet-host giants, making marked contrast to the case of planet-host dwarfs tending to be metal-rich. Generally, the metallicities of these comparatively young (typical age of $\sim 10^{9}$ yr) giants tend to be somewhat lower than those of dwarfs at the same age, and super-metal-rich ([Fe$/$H] $\gt$ 0.2) giants appear to be lacking. Apparent correlations were found between the abundances of C, O, and Na, suggesting that the surface compositions of these elements have undergone appreciable changes due to dredge-up of H-burning products by evolution-induced deep envelope mixing, which becomes more efficient for higher mass stars.

We present high-resolution central-to-outer rotation curves for Sb, SBb, Sc, and SBc galaxies. We discuss their general characteristics, particularly their central behavior, as well as dependencies on morphological types, activity, and peculiarity. The rotation curves generally show a steep nuclear rise and high-velocity central rotation, followed by a broad maximum in the disk and then a Ñat rotation due to the massive halo. Since the central high velocity and steep rise are common to all massive galaxies, they cannot be due to noncircular motions. Disk rotation curves of barred galaxies show larger dispersion than those of normal galaxies, probably because of noncircular motions. Interacting galaxies often show perturbed outer rotation curves, while their central rotation shows no particular peculiarity. In addition, central activities, such as starbursts and active galactic nuclei, appear to show no particular correlation with the property of rotation curves. This would suggest that the central activities are triggered by a more local e †ect than the global dynamical property.

Extensive statistical-equilibrium calculations on S I and Zn I were carried out, in order to investigate how the non-LTE effect plays a role in the determination of their abundances in F–K stars. Having checked on the spectra of representative F-type stars (Polaris, Procyon, $\alpha$ Per) and the Sun that our non-LTE corrections yield a reasonable consistency between the abundances derived from different lines, we tried an extensive non-LTE reanalysis of published equivalent-width data of S I and Zn I lines for metal-poor halo/disk stars. According to our calculations, S I 9212/9228/9237 lines suffer significant negative non-LTE corrections ($\lesssim 0.2 \hbox{--} 0.3 \,\mathrm{dex}$), while LTE is practically valid for S I 8683/8694 lines. As far as the very metal-poor regime is concerned, a marked discordance is observed between the $\mathrm{[S/Fe]}$ values from these two abundance indicators, in the sense that the former attains a nearly flat plateau (or even a slight downward bending) while the latter shows an ever-increasing trend with a further lowering of metallicity. The characteristics of $\mathrm{[Zn/Fe]}$ reported from recent LTE studies (i.e., an evident/slight increase of $\mathrm{[Zn/Fe]}$ with a decrease of $\mathrm{[Fe/H]}$ for very metal-poor/disk stars) were almost confirmed, since the non-LTE corrections for the Zn I 4722/4810 and 6362 lines (tending to be positive and gradually increasing toward lower $\mathrm{[Fe/H]}$) are quantitatively of less significance ($\lesssim 0.1 \,\mathrm{dex}$).

Abstract. In order to investigate the formation of O  7771-5 and [O ] 6300/6363 lines, extensive non-LTE calculations for neutral atomic oxygen were carried out for wide ranges of model atmosphere parameters, which are applicable to early-K through late-F halo/disk stars of various evolutionary stages. The formation of the triplet O  lines was found to be well described by the classical two-level-atom scattering model, and the non-LTE correction is practically determined by the parameters of the line-transition itself without any significant relevance to the details of the oxygen atomic model. This simplifies the problem in the sense that the non-LTE abundance correction is essentially determined only by the line-strength (W λ ), if the atmospheric parameters of T eff , log g, and ξ are given, without any explicit dependence of the metallicity; thus allowing a useful analytical formula with tabulated numerical coefficients. On the other hand, our calculations lead to the robust conclusion that LTE is totally valid for the forbidden An inspection of the parameter-dependence of this discordance indicates that the extent of the discrepancy tends to be comparatively lessened for higher T eff / log g stars, suggesting the preference of dwarf (or subgiant) stars for studying the oxygen abundances of metal-poor stars.

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