446 citations
- Lawrence Livermore National LaboratoryUS25 papers
- University of KentuckyUS25 papers
- Los Alamos National LaboratoryUS21 papers
- Royal Observatory of BelgiumBE20 papers
- University of OxfordGB18 papers
- Commissariat à l'Énergie Atomique et aux Énergies AlternativesFR14 papers
- Rutherford Appleton LaboratoryGB14 papers
- University of RochesterUS14 papers
- Imperial College LondonGB13 papers
- University of StrathclydeGB13 papers
- Centre National de la Recherche ScientifiqueFR12 papers
- Queen's University BelfastGB12 papers
12 papers · 1 filter
Space Telescope and Optical Reverberation Mapping Project. X. Understanding the Absorption-Line Holiday in NGC 5548
M. Dehghanian, G. J. Ferland, G. A. Kriss +27
The flux variations in the emission lines in active galactic nuclei (AGNs) are driven by variations in the ionizing continuum flux --which are usually reflected in the observable U…
The classical D-type expansion of spherical H II regions
Robin J. R. Williams, Thomas G. Bisbas, Thomas J. Haworth +1
Recent numerical and analytic work has highlighted some shortcomings in our understanding of the dynamics of H II region expansion, especially at late times, when the H II region a…
H, He-like recombination spectra I: -changing collisions for hydrogen
F. Guzmán, N. R. Badnell, R. J. R. Williams +3
Hydrogen and helium emission lines in nebulae form by radiative recombination. This is a simple process which, in principle, can be described to very high precision. Ratios of He I…
Collisional excitation of [C II], [O I] and CO in Massive Galaxies
R. E. A. Canning, G. J. Ferland, A. C. Fabian +5
Many massive galaxies at the centres of relaxed galaxy clusters and groups have vast reservoirs of cool (~10,000 K) and cold (~100 K) gas. In many low redshift brightest group and…
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…
On the Observability of Optically Thin Coronal Hyperfine Structure Lines
Marios Chatzikos, Gary Ferland, Robin Williams +1
We present Cloudy calculations for the intensity of coronal hyperfine lines in various environments. We model indirect collisional and radiative transitions, and quantify the colli…