A fast ionised wind in a star-forming quasar system at z ~ 1.5 resolved through adaptive optics assisted near-infrared data

¹ Dipartimento di Fisica e Astronomia, Alma Mater Studiorum, Università di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
e-mail: marcella.brusa3@unibo.it
² INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
³ INAF–Osservatorio Astronomico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
⁴ Frequency Measurement Group, National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba-central 3-1, Umezono 1-1-1, Tsukuba, 305-8563 Ibaraki, Japan
⁵ Department of Physics, University of Zagreb, Bijenicčka cesta 32, 10000 Zagreb, Croatia
⁶ European Southern Observatory, Karl-Schwarzschild-str. 2, 85748 Garching bei München, Germany
⁷ Max Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching bei München, Germany
⁸ INAF–Osservatorio Astronomico di Roma, via Frascati 33, 00078 Monte Porzio Catone (RM) Italy
⁹ Dipartimento di Astronomia e Scienza dello Spazio, Università degli Studi di Firenze, Largo E. Fermi 2, 50125 Firenze, Italy
¹⁰ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
¹¹ IRAP, Institut de Recherche en Astrophysique et Planétologie, CNRS, 14, avenue Édouard Belin, 31400 Toulouse, France
¹² Université de Toulouse, UPS-OMP, 31400 Toulouse, France

Received: 4 December 2015
Accepted: 3 February 2016

Abstract

Aims. Outflow winds are invoked in co-evolutionary models to link the growth of SMBH and galaxies through feedback phenomena, and from the analysis of both galaxies and active galactic nuclei (AGN) samples at z ~ 1−3, it is becoming clear that powerful outflows may be very common in AGN hosts. High-resolution and high S/N observations are needed to uncover the physical properties of the wind through kinematics analysis.

Methods. We exploited VLT/VIMOS, VLT/SINFONI, and Subaru/IRCS adaptive optics (AO) data to study the kinematics properties on the scale of the host galaxy of XID5395; this galaxy is a luminous, X-ray obscured starburst/quasar (SB-QSO) merging system at z ~ 1.5, detected in the XMM-COSMOS field, associated with an extreme [O II] emitter (with equivalent width, EW, ~200 Å). For the first time, we mapped the kinematics of the [O III] and Hα line complexes and linked them with the [O II] emission at high resolution. The high spatial resolution achieved allowed us to resolve all the components of the SB-QSO system.

Results. Our analysis, with a resolution of few kpc, reveals complexities and asymmetries in and around the nucleus of XID5395. The velocity field measured via non-parametric analysis reveals different kinematic components with maximum blueshifted and redshifted velocities up to ≳ 1300 km s^-1 that are not spatially coincident with the nuclear core. These extreme values of the observed velocities and spatial location can be explained by the presence of fast moving material. We also spectroscopically confirm the presence of a merging system at the same redshift as the AGN host.

Conclusions. We propose that EW as large as >150 Å in X-ray selected AGN may be an efficient criterion to isolate objects associated with the short, transition phase of “feedback” in the AGN-galaxy co-evolutionary path. This co-evolutionary path subsequently evolves into an unobscured QSO, as suggested from the different observational evidence (e.g. merger, compact radio emission, and outflow) we accumulated for XID5395.