Are quasar outflows a major contributor to AGN feedback? HST/COS to the rescue

HST/COS has opened a new discovery-space for studying quasar absorption outflows and their contribution to AGN feedback. Specifically, COS provides high quality FUV spectra covering the diagnostic-rich 500A-1050A rest-frame (hereafter, XUV) of medium redshift objects. The quality and quantity of XUV diagnostic troughs allow us to probe the very-high ionization phase, which carries 90% or more of the outflowing material, as well as determine the distance of most outflows from the central source (R). The first objective is impossible to achieve with the thousands of available ground-based spectra, and R can be measured in only 1% of them.

The COS archive includes observations of more than 200 quasars with suitable redshift, spectral resolution and S/N for the above XUV science. These observations were taken for studying intervening absorption systems, and quasar outflows detected in these spectra were rarely analyzed. Only 2 such XUV outflow analyses are currently found in the literature. One of these outflows is powerful enough to produce major AGN feedback effects.

WE PROPOSE an archive program to study the XUV outflows found in these spectra, where so far we identified 10 such unanalyzed outflows. Our preliminary study of one such observation shows 4 separated outflows situated at R 500 pc, with a combined kinetic luminosity larger than any of the reported outflows in the literature.