1 citations · 1 across the 4 of their papers we have counts for
7 papers
Helium Recombination Lines as a Probe of Abundance and Temperature Problems
Y. Zhang, R. H. Rubin, X. -W. Liu
The paper presents a simplified formula to determine an electron temperature, Te(He I), for planetary nebulae (PNe) using the He I 7281/6678 line flux ratio. In our previous studie…
Breit-Pauli energy levels, transition probabilities, and lifetimes for 3d^5 levels in Fe IV of astrophysical interest
Charlotte Froese Fischer, Robert H. Rubin
Energy levels, lifetimes, and transition probabilities for transitions between computed levels of 3d^5 of Fe IV are reported. The E2 and M1 transition probabilities are compared wi…
Flux ratio [Ne V] 14.3/24.3 as a test of collision strengths
R. H. Rubin
From ISO [Ne V] 14.3/24.3 micron line flux ratios, we find that 10 out of 20 planetary nebulae (PNs) have measured ratios below the low-electron density (N_e) theoretical predicted…
The ionization equilibrium of iron in H II regions
M. Rodriguez, R. H. Rubin
We study the ionization equilibrium of Fe using photoionization models that incorporate improved values for the ionization and recombination cross-sections and the charge-exchange…
ISO measurements of [CII] line variations in galaxies
S. Malhotra, G. Helou, G. Stacey +11
We report measurements of the [CII] fine structure line at 157.714 micron in 30 normal star-forming galaxies with the Long Wavelength Spectrometer (LWS) on the Infrared Space Obser…
The Mid-Infrared Color of NGC 6946
G. Helou, S. Malhotra, C. A. Beichman +10
We analyze the new mid-infrared maps of NGC 6946 for variations in the color ratio of the 7-to-15 micron emission. Our preliminary findings are that this mid-infrared color is rema…