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Gas density histograms of galaxies: the observational density probability function of the interstellar gas density

Published online by Cambridge University Press:  05 March 2015

Handa Toshihiro
Depart. Astron. & Phys., Kagoshima Univ., Korimoto 1-21-35, Kagoshima 890-0065, Japan email:
Yoda Takahiro
Yamanashi Gakuin highschool
Kuno Nario
National Astronomical Observatory of Japan
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In the steady state, the probability density function (PDF) of the gaseous interstellar matter (ISM) can be observed as a gas density histogram (GDH) of all cells in the system. We made GDHs of the Milky Way Galaxy (MWG) using Galactic plane surveys in CO lines. We found that the GDH in the MWG is log-normal which suggests that the density structure of the molecular gas is a result of many stochastic processes. Using the Nobeyama CO atlas, we made GDHs of nearby galaxies but in column density. Although some galaxies show log-normal, the others show completely different shapes, suggesting that the density structure of galaxies may be different from galaxy to galaxy.

Contributed Papers
Copyright © International Astronomical Union 2015 


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