AB Dor, Speedy Mic, and Rst 137B are in their early post-T Tauri evolutionary phase ( ~107 K toward the saturated-supersaturated boundary but a decline beyond this among supersaturated stars. The coronal Fe abundances of the stellar sample are inversely correlated with LX/Lbol, declining slowly with rising LX/Lbol, but with a much more sharp

The recent finding that the integrated galactic initial stellar mass function, comprising all newly formed stars in all young star clusters, has, through its dependence on the star formation rate, a steeper slope in the high mass regime than the underlying canonical initial mass function of each star cluster individually offers new insights into

We present the results of high-resolution absorption-line spectroscopy of three face-on galaxies, NGC 98, NGC 600, and NGC 1703, with the aim of searching for box/peanut (B/P) shaped bulges. These observations test and confirm, for the first time, the prediction that face-on B/P-shaped bulges can be recognized by two minima in the profile along the

Bars are expected to play an important role in galactic dynamics. Since the rest-frame wavelength of near-infrared images of high redshift galaxies lies in the optical, a reliable comparison of low and high redshift bars requires an understanding of how the properties of a bar depend on the observing wavelength. For this purpose, we compare bar

We present deep color profiles for a sample of 415 disk galaxies within the redshift range 0.1

Collisional excitation of neutral hydrogen atoms can significantly increase the intensity of Balmer lines with respect to pure recombination. If this effect is not taken into account, the abundance analysis of these objects returns biased values, and the bias may be significant if accuracies better than a few percent are required. The most affected