NuSTAR View of the Black Hole Wind in the Galaxy Merger IRAS F11119+3257

Abstract

Galactic winds driven by active galactic nuclei (AGNs) have been invoked to play a fundamental role in the co-evolution between supermassive black holes and their host galaxies. Finding observational evidence of such feedback mechanisms is of crucial importance and it requires a multi-wavelength approach in order to compare winds at different scales and phases. In Tombesi et al., we reported the detection of a powerful ultra-fast outflow (UFO) in the Suzaku X-ray spectrum of the ultra-luminous infrared galaxy IRAS F11119+3257. The comparison with a galaxy-scale OH molecular outflow observed with Herschel in the same source supported the energy-conserving scenario for AGN feedback. The main objective of this work is to perform an independent check of the Suzaku results using the higher sensitivity and wider X-ray continuum coverage of NuSTAR. We clearly detect a highly ionized Fe K UFO in the 100 ks NuSTAR spectrum with parameters N H = (3.2 ± 1.5) × 1024 cm-2, log ? = ${4.0}_{-0.3}^{+1.2}$ erg s-1 cm, and ${v}_{\mathrm{out}}={0.253}_{-0.118}^{+0.061}c$. The launching radius is likely at a distance of r = 16r s from the black hole. The mass outflow rate is in the range of ${\dot{M}}_{\mathrm{out}}$ sime 0.5–2 M ? yr-1. The UFO momentum rate and power are ${\dot{P}}_{\mathrm{out}}$ sime 0.5–2 L AGN/c and ${\dot{E}}_{\mathrm{out}}$ sime 7%–27% L AGN, respectively. The UFO parameters are consistent between the 2013 Suzaku and the 2015 NuSTAR observations. Only the column density is found to be variable, possibly suggesting a clumpy wind. The comparison with the energetics of molecular outflows estimated in infrared and millimeter wavelengths support a connection between the nuclear and galaxy-scale winds in luminous AGNs.