AGN–starburst connection in NGC 7582: Gemini near-infrared spectrograph integral field unit observations

We analyse two-dimensional near-infrared K-band spectra from the inner 660 × 315 pc 2 of the Seyfert galaxy NGC 7582 obtained with the Gemini near-infrared spectrograph integral field unit at a spatial resolution of ≈50 pc and spectral resolving power R ≈ 5900. The nucleus harbours an unresolved source well reproduced by a blackbody of temperature T ≈ 1050 K, which we attribute to emission by circumnuclear dust located closer than 25 pc from the nucleus, with a total mass of ≈3 × 10 −3 M� . Surrounding the nucleus, we observe a ring of active star formation, apparently in the Galactic plane, with a radius of ≈190 pc, an age of ≈5 Myr and a total mass of ionized gas of ≈3 × 10 6 M� . The radiation of the young stars in the ring accounts for at least 80 per cent of the ionization observed in the Brγ emitting gas, the remaining being due to the radiation emitted by the active nucleus. The stellar kinematics was derived using the CO absorption band at 2.29 μm and reveals: (i) a distorted rotation pattern in the radial velocity field with kinematic centre apparently displaced from the nuclear source by a few tens of parsec; (ii) a high-velocity dispersion in the bulge of σ ∗ = 170 km s −1 and (iii) a partial ring of σ ∗ = 50 km s −1 , located close to the Brγ emitting ring, but displaced by ≈50 pc towards the nucleus, interpreted as due to stars formed from cold gas in a previous burst of star formation. The kinematics of the ionized gas shows a similar rotation pattern to that of the stars, plus a blueshifted component with velocities ≥ 100 km s −1 interpreted as due to an outflow along the ionization cone, which was partially covered by our observations. The mass outflow rate in the ionized gas was estimated as u