WHAM Observations of Ionized Gas in the Smith Cloud HVC

Type Conference Paper
Names Alex S. Hill, L. Haffner
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #215, #415.27
Volume 42
Pages 265
Date January 1, 2010
URL http://adsabs.harvard.edu/abs/2010AAS...21541527H
Library Catalog NASA ADS
Abstract We present new observations of 10000 K ionized gas in the Smith Cloud, a high velocity cloud thought to be interacting with the interstellar medium of the Galaxy 3 kpc below the midplane. We have obtained H-alpha, H-beta, [N II], [S II], and [O III] spectra of the cloud with the Wisconsin H-Alpha Mapper (WHAM). Previously, we have shown that the ionized component has a mass of > 106 Mȯ (comparable to the mass of the neutral component), with relatively bright H-alpha emission in directions with faint H I 21 cm emission. Detections of [S II] and [N II] constrain the temperature and metallicity of the infalling ionized gas. New WHAM observations extend the H-alpha map to search for diffuse emission not associated with H I and probe the kinematics and metallicity of the tail. We also report [N II] and [S II] spectra in four directions along the axis of the cloud in order to explore the kinematics and metallicity distribution across the cloud. WHAM is funded by the National Science Foundation through grant AST 0607512 to the University of Wisconsin-Madison.
UW-Madison Astronomy Home