Quasar Line Emission at the Bluest Extreme UV Wavelengths
Abstract
Quasars exhibit remarkably consistent emission lines and line strengths across a large range of luminosity and mass. These lines are fairly well modeled as arising in photoionized regions using a locally optimally emitting cloud (LOC) model. However, the bluest observable extreme-UV wavelengths (~300-500 Å) are puzzling, showing strong line variability between objects and almost universally lacking the only strong line predicted by standard photoionization, He II Lyα. We discuss the array of possible lines seen in very low resolution spectra, and present the most detailed medium-resolution observations yet of a quasar exhibiting likely line emission in this region. We compare with photoionization models, and offer a tentative line identification.
- Publication:
-
American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22530304S