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Southern Galactic Plane Survey Measurements of the Spatial Power Spectrum of Interstellar H I in the Inner Galaxy

Citation

Dickey, JM and McClure-Griffiths, NM and Stanimirovic, S and Gaensler, BM and Green, A, Southern Galactic Plane Survey Measurements of the Spatial Power Spectrum of Interstellar H I in the Inner Galaxy, Astrophysical Journal, 561, (1) pp. 264-271. ISSN 0004-637X (2001) [Refereed Article]

DOI: doi:10.1086/323409

Abstract

Using data from the Southern Galactic Plane Survey, we have measured the spatial power spectrum of the interstellar neutral atomic hydrogen in the fourth Galactic quadrant. This function shows the same power-law behavior that has been found for H I in the second quadrant of the Milky Way and in the Magellanic Clouds with the same slope. When we average over velocity intervals broader than the typical small-scale velocity dispersion, we find that the slope steepens, from ≃ -3 to ≃ -4 for the warm gas, as predicted by theories of interstellar turbulence if the column density fluctuations are dominated by variations in the gas density on small spatial scales. The cool gas shows a different increase of slope, which suggests that it is in the regime of turbulence dominated by fluctuations in the velocity field. Overall, these results confirm that the small-scale structure and motions in the neutral atomic medium are well described by a turbulent cascade of kinetic energy.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical and Space Sciences
Research Field:Galactic Astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Physical Sciences
Author:Dickey, JM (Professor John Dickey)
ID Code:34858
Year Published:2001
Web of Science® Times Cited:87
Deposited By:Mathematics and Physics
Deposited On:2007-10-17
Last Modified:2007-10-17
Downloads:0

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