A new ionization correction factor (ICF) scheme for He(+) is developed, based on the definition of the radiation softness parameter eta (Vilchez and Pagel, 1988) which is very sensitive to the effective temperature of the ionizing star(s) and, therefore, a good indicator of the He(+)-He(0) ionization structure while remaining insensitive to other

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Nine type I post-main-sequence nebulae were observed in CO J = 2-1 using the NRAO 12-m antenna at Kitt Peak. It is found that, at the most, 20 percent of type I sources have antenna temperatures of greater than 0.2 K. The results suggest secondary kinematic splitting of the primary emission shell, and confirm the presence of high velocity outflows

This paper describes results obtained on a simulation of two high-velocity encounters of NGC 4782/4783 and NGC 2672/2673 binary elliptical galaxies which differ substantially in mass ratio (about 1 for the first pair, and about 10 for the second). CCD images and velocities obtained from digital spectra were used to constrain simulations of the

Observations of a broad area at the core of M82, obtained with spatial resolution 30 arcsec and velocity resolution 15.6 km/sec in the J = 2-1 line of CO using the 12-m NRAO antenna at KPNO, are reported. The data are presented in graphs and contour maps and characterized in detail. It is found that the J = 2-1 map is similar to the J = 1-0 map of

A method to explore the column density of the Local Interstellar Medium (LISM) using absorptions in the resonance H and K lines of Mg II. The intrinsic strengths of these lines in the temperature and density conditions prevailing in warm clouds in the LISM allows them to be used to explore many lines of sight where lines such a NaD and Ca II H and