136 citations · 760 across the 27 of their papers we have counts for
6 papers · 1 filter
PopRatio: A program to calculate atomic level populations in astrophysical plasmas
A. I. Silva, S. M. Viegas
We describe a Fortran 90 program to calculate population ratios of atomic levels. The program solves the equations of statistical equilibrium considering all possible bound-bound p…
Temperature of the central stars of planetary nebulae and the effect of the nebular optical depth
R. Gruenwald, S. M. Viegas
The effect of the nebula optical depth on the determination of the temperature (T*) of the central stars in planetary nebulae is discussed. Based on photoionization models for plan…
A grid of composite models for the simulation of the emission-line spectra from the NLR of active galaxies
M. Contini, S. M. Viegas
A grid of composite models for the narrow line region of active galaxies, which consistently account for both the effect of a photoionizing radiation from the active center and of…
On the Abundance Gradient of the Galactic Disk
Lucimara P. Martins, Sueli M. M. Viegas
Estimates of the gas temperature in planetary nebulae obtained from the [O III] emission line ratio and from the Balmer discontinuity indicate differences reaching up to 6000 K (Li…
Morphology and kinematics of Planetary Nebulae II. A Diabolo model for NGC 3132
H. Monteiro, C. Morisset, R. Gruenwald +1
We use a 3D photoionization modeling tool to study the morpho-kinematic properties of the Planetary Nebula (PN) NGC 3132. We show that it is possible to reproduce the low resolutio…
The optical-ultraviolet continuum of Seyfert 2 galaxies
M. Contini, S. M. Viegas
This paper aims to understand the continuum of Seyfert 2 galaxies. By fitting the single galaxies in the sample of Heckman et al. (1995) with composite models (shock+ photoionizati…