2006/12/29 by P. Hennebelle, Hennebelle, P., E. Audit +4
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #FOS: Physical sciences #Spectroscopy and Laser Applications #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0612779
accepted for publication in A&A
arxiv created 2006/12/29 · openalex publication_date 2006/12/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is necessary to understand the dynamics of the atomic gas to use complex modeling and to carry out detailed comparisons between theoretical models and observations.In a companion paper, we present high resolution bidimensional numerical simulations of the interstellar atomic hydrogen. Here, we further characterize these simulations and we compare our results with various observations.We give statistics of the column density and velocity along the line of sight and show that they compare favorably with observations of high-latitude lines of sight. We compute synthetic HI spectra and qualitatively discuss the information that could be inferred if these spectra were observed. Finally, we extract CNM clouds and study their physical properties finding strong similarities with real clouds. In particular, we find that the clouds follow Larson-type relations, i.e. M ∝ Lγ, where γ≃ 1.7 (we speculate that in 3D, γ≃ 2.5) and √(<δv2>) ∝ L0.4. We also find that the distribution, \cal N(N), of the column density, N, of the CNM structures formed in the simulation follows \cal N(N) ∝ N-1.2 which is marginally compatible with the observational result obtained by Heiles & Troland (2005). From the mass-size relation and the mass spectrum, we derive an exponent for the column density distribution close to the value obtained in the numerical simulation. We conclude that the simulations reproduce various observational features reasonably well....