文摘
\(\mathrm{[OIII]}\lambda 5007\) 鈥渂lue outliers鈥濃€攖hat are suggestive of outflows in the narrow line region of quasars鈥攁ppear to be much more common at intermediate \(z\) (high luminosity) than at low \(z\). About \(40~\%\) of quasars in a Hamburg ESO intermediate \(z\) sample of 52 sources qualify as 鈥渂lue outliers鈥?(i.e., quasars with \(\mbox{[OIII]}\lambda\lambda 4959,5007\) lines showing large systematic blueshifts with respect to rest frame). We discuss major findings on what has become an intriguing field in active galactic nuclei research and stress the relevance of 鈥渂lue outliers鈥?to feedback and host galaxy evolution. Keywords Galaxies: active Quasars: emission lines Quasars: general Techniques: spectroscopic Astronomical databases: surveys