Date:
Tue, 07/01/202012:30-13:30
Location:
Institute Moadon, Beitan 9
Ionized AGN outflows are less powerful than assumed: A multi-wavelength study of outflows in type II AGN
Abstract:
In this talk I will show that multi-wavelength observations can provide novel constraints on the properties of ionized gas outflows in AGN. I will present evidence that the infrared emission in active galaxies includes a contribution from dust which is mixed with the outflow and is heated by the AGN. We detect this infrared component in thousands of AGN for the first time, and use it to constrain the outflow location. By combining this with optical emission lines, we constrain the mass outflow rates and energetics in a sample of 234 type II AGN, the largest such sample to date. The key ingredient of our new outflow measurements is a different method to estimate the electron density using the ionization parameter and location of the flow. The inferred densities, ~10^(4.5) cm^(-3), are two orders of magnitude larger than found in most other cases of ionized outflows. As a result, the inferred mass outflow rates and kinetic coupling efficiencies are 1–2 orders of magnitude lower than previous estimates, and 3–4 orders of magnitude lower than the typical requirement in hydrodynamic cosmological simulations. These results have significant implications for the relative importance of ionized outflows feedback in this population. I will finish the talk by discussing some unresolved issues that prevent us from drawing more concrete conclusions regarding the importance of feedback in typical AGN, and will show how observations of outflows in post starburst E+A galaxies can help reduce these uncertainties.
Abstract:
In this talk I will show that multi-wavelength observations can provide novel constraints on the properties of ionized gas outflows in AGN. I will present evidence that the infrared emission in active galaxies includes a contribution from dust which is mixed with the outflow and is heated by the AGN. We detect this infrared component in thousands of AGN for the first time, and use it to constrain the outflow location. By combining this with optical emission lines, we constrain the mass outflow rates and energetics in a sample of 234 type II AGN, the largest such sample to date. The key ingredient of our new outflow measurements is a different method to estimate the electron density using the ionization parameter and location of the flow. The inferred densities, ~10^(4.5) cm^(-3), are two orders of magnitude larger than found in most other cases of ionized outflows. As a result, the inferred mass outflow rates and kinetic coupling efficiencies are 1–2 orders of magnitude lower than previous estimates, and 3–4 orders of magnitude lower than the typical requirement in hydrodynamic cosmological simulations. These results have significant implications for the relative importance of ionized outflows feedback in this population. I will finish the talk by discussing some unresolved issues that prevent us from drawing more concrete conclusions regarding the importance of feedback in typical AGN, and will show how observations of outflows in post starburst E+A galaxies can help reduce these uncertainties.