The Infrared Medium-Deep Survey II: How to Trigger Radio-AGN? Hints from Their Environments

摘要: Activity at the centers of galaxies, during which central supermassive black hole is accreting material, nowadays accepted to be rather ubiquitous and most probably a phase every galaxy's evolution. It has been suggested that galactic mergers interactions may culprits behind triggering nuclear activity. We use near-infrared data from new Infrared Medium-Deep Survey (IMS) Deep eXtragalactic (DXS) VIMOS-SA22 field radio 1.4 GHz FIRST survey deep VLA study environments radio-AGN over an area ~25 sq. degrees down flux limit 0.1 mJy J-band magnitude 23 mag AB. Radio-AGN are predominantly found in similar those control galaxies redshift, magnitude, U-R rest-frame absolute color. However, sub-population up 100 times denser than their sources. thus preclude merging as dominant mechanism radio-AGN. Through fitting broadband spectral energy distribution least dense environments, we find show higher radio-loudness, star formation efficiencies, accretion rates, typical so-called high-excitation These differences tend disappear z>1. interpret our results terms different for these sources driven by mass-loss through winds young stars created observed ongoing formation.