activity
20002025
most citedMetallicities and Abundance Ratios from Quasar Broad Emission Lines

178 citations · 539 across the 16 of their papers we have counts for

collaborators

17 papers

astro-ph.GA2025

H-, He-like recombination spectra -- V: On the dependence of the simulated line intensities on the number of electronic levels of the atoms

F. Guzmán, M. Chatzikos, G. Ferland

This paper presents a study of the dependence of the simulated intensities of recombination lines from hydrogen and helium atoms on the number of -resolved principal quantum…

astro-ph.IM2020

2018 NASA Laboratory Astrophysics Workshop: Scientific Organizing Committee Report

N. Brickhouse, G. J. Ferland, S. Milam +6

This report provides detailed findings on the critical laboratory astrophysics data needs that are required to maximize the scientific return for NASA's current and near-term plann…

astro-ph.GA2019★ 13 cited

H-, He-like recombination spectra III: -changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination lines

F. Guzmán, M. Chatzikos, P. A. M. van Hoof +4

At intermediate to high densities, electron (de-)excitation collisions are the dominant process for populating or depopulating high Rydberg states. In particular, the accurate know…

astro-ph.GA2017

Which Stars are Ionizing the Orion Nebula ?

C. R. O'Dell, W. Kollatschny, G. J. Ferland

The common assumption that Theta-1-Ori C is the dominant ionizing source for the Orion Nebula is critically examined. This assumption underlies much of the existing analysis of the…

astro-ph.GA2014★ 16 cited

Implications of Coronal Line Emission in NGC 4696

M. Chatzikos, R. J. R. Williams, G. J. Ferland +7

We announce a new facility in the spectral code CLOUDY that enables tracking the evolution of a cooling parcel of gas with time. For gas cooling from temperatures relevant to galax…

astro-ph.GA2013★ 19 cited

The Nature of the H2-Emitting Gas in the Crab Nebula

C. T. Richardson, J. A. Baldwin, G. J. Ferland +4

Understanding how molecules and dust might have formed within a rapidly expanding young supernova remnant is important because of the obvious application to vigorous supernova acti…