The Bulletin of The Korean Astronomical Society (천문학회보)
- Volume 40 Issue 1
- /
- Pages.42.3-43
- /
- 2015
- /
- 1226-2692(pISSN)
AGN gas outflows out to z ~ 0.2
- Woo, Jong-Hak (Astronomy Program, Department of Physics and Astronomy, Seoul National University) ;
- Son, Donghoon (Astronomy Program, Department of Physics and Astronomy, Seoul National University) ;
- Bae, Hyun-Jin (Astronomy Program, Department of Physics and Astronomy, Seoul National University)
- Published : 2015.04.10
Abstract
Using a large sample of 32,000 type 2 AGNs out to z = 0.2, we present the statistical results on the ionized gas outflows, based on the analysis of the velocity shift of narrow emission lines with respect to the systemic velocity measured from the stellar absorption lines. Considering the projection effect, the fraction of type 2 AGNs with the [O III] velocity offset, which is ~50%, is comparable to that of type 1 AGNs. The velocity dispersion of [OIII] is typically larger than that of Ha, suggesting that outflow is prevalent in type 2 AGNs. A weak correlation of the OIII luminosity with velocity shift and velocity dispersion indicates that outflow velocity is stronger for higher luminosity AGNs. Based on our 3-D biconical outflow models with simple assumptions on the velocity structure, we simulate the projected 2-D velocity and velocity dispersion maps, which are spatially integrated to reproduce the measurements of SDSS AGNs. By comparing the distribution of the measured velocity and velocity dispersion of OIII, with the model grids, we constrain the intrinsic outflow velocities. The outflow velocity ranges from a few hundreds to a thousand km/s, implying a strong feedback to ISM.
Keywords