| Type |
Conference Paper |
| Names |
Rex C. Beaber, L. M. Haffner, R. J. Reynolds, G. J. Madsen |
| Conference Name |
Bulletin of the American Astronomical Society |
| Volume |
38 |
| Pages |
922 |
| Date |
December 1, 2006 |
| URL |
http://adsabs.harvard.edu/abs/2006AAS...209.1722B |
| Library Catalog |
NASA ADS |
| Abstract |
Doubly-ionized oxygen continues to be an intriguing tracer of physical
conditions in diffuse ionized gas. Although [O III] emission is strong
in many classical H II and PNe photoionized environments, [O
III]/H-alpha has been consistently measured to be very low in the Warm
Ionized Medium (WIM) of the Milky Way. Understanding how this ratio
varies throughout the Galaxy is important for investigating changes in
the dominant ionizing mechanism in a low-density medium. In some edge-on
spiral galaxies, studies have found this line ratio to increase with
height above the galactic plane, which could be explained by an increase
in temperature as well as a shift in the dominant ionization mechanism
for doubly-ionized oxygen with height. The Wisconsin H-Alpha Mapper
(WHAM) provides unprecedented spectral resolution and sensitivity for
studying the diffuse interstellar environments of our Galaxy. We present
three new WHAM maps of [O III] emission towards directions of known
ionizing sources. These regions give us new insight into the physical
conditions of low-density, photoionized gas and deliver unique
measurements of the ionizing continuum from the sources. WHAM is
supported by NSF grant AST 02-04973. |