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The Atomic Component

Kulkarni, Shrinivas R. and Heiles, Carl (1987) The Atomic Component. In: Interstellar Processes. Astrophysics and Space Science Library. No.134. Springer Netherlands , Dordrecht, pp. 87-122. ISBN 9789027724854.

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We review the physical conditions and the distribution of the three phases which consitute the atomic component: the cold clouds, the warm, neutral medium and the warm, ionized medium. Together, these three phases occupy about ≳ 40% of the interstellar volume and contain half the interstellar mass. The size of the H I disk is comparable or exceeds that of the stellar disk. In the outer Galaxy, a spiral pattern is clearly discernable. We discuss extensively the distribution of the three phases near the sun as well as the physics and the limitations of various probes that have been used to study the atomic component. The ionization of the phases is studied in depth and we conclude that most of the interstellar electrons reside in the warm, ionized medium. We review various determinations of interstellar pressure and its scale height. Finally, we derive the filling factors of the atomic phases as a function of z. [Unless otherwise stated, R₀ = 10 kpc]

Item Type:Book Section
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URLURL TypeDescription ReadCube access
Kulkarni, Shrinivas R.0000-0001-5390-8563
Additional Information:© D. Reidel Publishing Company 1987. This work was supported in part by an NSF grant to CH and a Millikan Fellowship to SRK. We gratefully acknowledge help of S. Vogel (CIT) for constructive criticisms.
Funding AgencyGrant Number
Robert A. Millikan FellowshipUNSPECIFIED
Subject Keywords:Column Density; Scale Height; Atomic Component; Spin Temperature; Cold Medium
Series Name:Astrophysics and Space Science Library
Issue or Number:134
Record Number:CaltechAUTHORS:20201001-145810416
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105727
Deposited By: George Porter
Deposited On:02 Oct 2020 14:40
Last Modified:16 Nov 2021 18:45

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