Tracing UV Emission from Warm Gas in Shocked Stellar Outflows
Abstract
The near-UV lines of Mg II at 2796 & 2803 Å have been observed from space for decades in solar system objects, stars, the interstellar medium and galaxies. Most Mg II observations have been spectroscopic, but the Hubble Space Telescope (HST) has a narrowband imaging filter that allows Mg II emission distributions in stellar outflows within star forming regions and other environments to be compared with common visible wavelength lines such as H-alpha, [N II]6584, [S II]6724, [O III]5007, [O II]3727, etc. Some recent examples of HST Mg II imaging will be shown that indicate the potential for exploiting this diagnostic feature to trace warm (~3000-5000 K), dense gas that may bridge the gap between tracers of hotter atomic and cooler molecular structures and flows. Such examples can be used to build the case for a dedicated imaging survey in Mg II and other UV lines (e.g., C II], O II], C IV) of large regions of the Milky Way and nearby galaxies, possibly carried out with a smallsat class telescope from the lunar surface or by other means to achieve sub-arcsecond spatial resolution.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23332005M