Ionized gas in the halos of edge-on starburst galaxies: Evidence for supernova-driven superwinds
- Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, 7000 East Avenue, L-413, Livermore, California 94550 (United States)
- Rowland Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)
Supernova-driven galactic winds ({open_quote}{open_quote}superwinds{close_quote}{close_quote}) have been invoked to explain many aspects of galaxy formation and evolution. Such winds should arise when the supernova rate is high enough to create a cavity of very hot shock-heated gas within a galaxy. This gas can then expand outward as a high-speed wind that can accelerate and heat ambient interstellar or circum-galactic gas causing it to emit optical line radiation and/or thermal X-rays. Theory suggests that such winds should be common in starburst galaxies and that the nature of the winds should depend on the star formation rate and distribution. In order to systematize our observational understanding of superwinds (determine their incidence rate and the dependence of their properties on the star formation that drives them) and to make quantitative comparisons with the theory of superwinds, we have analyzed data from an optical spectroscopic and narrow-band imaging survey of an infrared flux-limited ({ital S}{sub 60 {mu}m}{ge}5.4 Jy) sample of about 50 IR-warm ({ital S}{sub 60 {mu}m}/{ital S}{sub 100 {mu}m}{approx_gt}0.4), starburst galaxies whose stellar disks are viewed nearly edge-on ({ital b}/{ital a}{approx_gt}2). This sample contains galaxies with infrared luminosities from {approx_equal}10{sup 10}{endash}10{sup 12} {ital L}{sub {circle_dot}} and allows us to determine the properties of superwinds over a wide range of star formation rates. We have found that extraplanar emission-line gas is a very common feature of these edge-on, IR-bright galaxies and the properties of the extended emission-line gas are qualitatively and quantitatively consistent with the superwind theory. We can summarize these properties as morphological, ionization, dynamical, and physical. {copyright} {ital 1996 The American Astronomical Society.}
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 285849
- Journal Information:
- Astrophysical Journal, Vol. 462, Issue 2; Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
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