Zusammenfassung
In this paper we follow up on our previous detection of nuclear ionized
outflows in the most massive (log(M*/Msun) >= 10.9) z~1-3 star-forming galaxies
(Forster Schreiber et al.), by increasing the sample size by a factor of six
(to 44 galaxies above log(M*/Msun) >= 10.9) from a combination of the
SINS/zC-SINF, LUCI, GNIRS, and KMOS^3D spectroscopic surveys. We find a fairly
sharp onset of the incidence of broad nuclear emission (FWHM in the Ha, NII,
and SII lines ~ 450-5300 km/s), with large NII/Ha ratios, above
log(M*/Msun) ~ 10.9, with 66+/-15% of the galaxies in this mass range
exhibiting this component. Broad nuclear components near and above the
Schechter mass are similarly prevalent above and below the main sequence of
star-forming galaxies, and at z~1 and ~2. The line ratios of the nuclear
component are fit by excitation from active galactic nuclei (AGN), or by a
combination of shocks and photoionization. The incidence of the most massive
galaxies with broad nuclear components is at least as large as that of AGNs
identified by X-ray, optical, infrared or radio indicators. The mass loading of
the nuclear outflows is near unity. Our findings provide compelling evidence
for powerful, high-duty cycle, AGN-driven outflows near the Schechter mass, and
acting across the peak of cosmic galaxy formation.
Nutzer