AR 16601 (Archival Research)

Mon Jul 15 05:09:04 GMT 2024

Principal Investigator: Nahum Arav
PI Institution: Virginia Polytechnic Institute and State University
Investigators (xml)

Title: Measuring the contribution of quasar outflows to AGN feedback
Cycle: 29

There has been major progress recently in the study of quasar absorption outflows and their potential contribution for AGN feedback. HST spectral observations of the 500A-1050A rest-frame (hereafter, EUV500) in medium redshift objects (z~1) uncovered a rich phenomenology of absorption troughs. The quality and quantity of EUV500 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 EUV500 effort yielded the most energetic outflows measured to date with enough kinetic luminosity to be major agents of AGN feedback processes. The HST spectral UV archive includes observations of more than 800 quasars. These observations were taken for studying intervening absorption systems, and quasar outflows detected in these spectra were rarely analyzed. WE PROPOSE an archive program to study the EUV500 outflows found in these spectra. Based on previous studies, we expect to find 20-30 very high ionization outflows (tripling the existing sample), and 10-15 outflows with measurable distance (doubling the existing sample).