Properties of the thinnest cold HI clouds in the diffuse interstellar medium

2006/10/12 by Snezana Stanimirovic, Snežana Stanimirović, Stanimirovic, Snezana +4
Chemistry · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Spectroscopy and Laser Applications #astro-ph

paper · pdf · doi:10.48550/arxiv.astro-ph/0610388

to be published in the proceedings of the meeting on "Small Ionized and Neutral Structures in the Diffuse Interstellar Medium" (ASP Conference Series)

arxiv created 2006/10/12 · openalex publication_date 2006/10/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We have obtained deep HI observations in the direction of 22 continuum sources without previously detected cold neutral medium (CNM). 18 CNM clouds were detected with the typical HI column density of 3×10¹⁸ cm^-2. Our surprisingly high detection rate suggests that clouds with low HI column densities are quite common in the interstellar medium. These clouds appear to represent an extension of the traditional CNM cloud population, yet have sizes in hundreds to thousands of AUs. We present properties of the newly-detected CNM sample, and discuss several theoretical avenues important for understanding the production mechanisms of these clouds.

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