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Full-Text Articles in Physical Sciences and Mathematics
The Physical Conditions Within Dense Cold Clouds In Cooling Flows - Ii, Gary J. Ferland, A. C. Fabian, R. M. Johnstone
The Physical Conditions Within Dense Cold Clouds In Cooling Flows - Ii, Gary J. Ferland, A. C. Fabian, R. M. Johnstone
Physics and Astronomy Faculty Publications
This is a progress report on our numerical simulations of conditions in the cold cores of cooling flow condensations. The physical conditions in any non-equilibrium plasma are the result of a host of microphysical processes, many involving reactions that are research areas in themselves. We review the dominant physical processes in our previously published simulations, to clarify those issues that have caused confusion in the literature. We show that conditions in the core of an X-ray-illuminated cloud are very different from those found in molecular clouds, largely because carbon remains substantially atomic and provides powerful cooling through its far infrared …
Comparing Simulations And Observations Of The Ly Alpha Forest. I. Methodology, Ce Petry, Cd Impey, N Katz, Dh Weinberg, Le Hernquist
Comparing Simulations And Observations Of The Ly Alpha Forest. I. Methodology, Ce Petry, Cd Impey, N Katz, Dh Weinberg, Le Hernquist
Astronomy Department Faculty Publication Series
We describe techniques for comparing spectra extracted from cosmological simulations and observational data, using the same methodology to link Lyα properties derived from the simulations with properties derived from observational data. The eventual goal is to measure the coherence or clustering properties of Lyα absorbers using observations of quasar pairs and groups. We quantify the systematic underestimate in opacity that is inherent in the continuum-fitting process of observed spectra over a range of resolution and signal-to-noise ratio (S/N). We present an automated process for detecting and selecting absorption features over the range of resolution and S/N of typical observational data …