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Ionization of Infalling Gas

Published online by Cambridge University Press:  17 September 2012

L.M. Haffner ,
A.K. Duncan ,
S.M. Hoffman ,
G.J. Madsen ,
A.S. Hill  and
R.J. Reynolds
L.M. Haffner
Affiliation:
Department of Astronomy, University of Wisconsin , Madison, WI, USA
A.K. Duncan
Affiliation:
Department of Astronomy, University of Wisconsin , Madison, WI, USA
S.M. Hoffman
Affiliation:
Department of Astronomy, University of Wisconsin , Madison, WI, USA
G.J. Madsen
Affiliation:
School of Physics, The University of Sydney, NSW 2006, Australia
A.S. Hill
Affiliation:
Department of Astronomy, University of Wisconsin , Madison, WI, USA
R.J. Reynolds
Affiliation:
Department of Astronomy, University of Wisconsin , Madison, WI, USA
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Abstract

Hα emission from neutral halo clouds probes the radiation and hydrodynamic conditions in the halo. Armed with such measurements, we can explore how radiation escapes from the Galactic plane and how infalling gas can survive a trip through the halo. The Wisconsin H-Alpha Mapper (WHAM) is one of the most sensitive instruments for detecting and mapping optical emission from the ISM. Here, we present recent results exploring the ionization of two infallling high-velocity complexes. First, we report on our progress mapping Hα emission covering the full extent of Complex A. Intensities are faint (100 mR; EM 0.2pccm−6) but correlate on the sky and in velocity with 21-cm emission. Second, we explore the ionized component of some Anti-Center Complex clouds studied by Peek et al. (2007) that show dynamic shaping from interaction with the Galactic halo.

Type
Research Article
Information
European Astronomical Society Publications Series , Volume 56: The Role of the Disk-Halo Interaction in Galaxy Evolution: Outflow vs. Infall? , 2012 , pp. 319 - 322
Copyright
© EAS, EDP Sciences, 2012

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References

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