The XMM-Newton and NuSTAR view of IRASF11119+3257

I. Detection of multiple ultra fast outflow components and a very cold corona

¹ INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti, 93/3, 40129 Bologna, Italy
² Department of Physics and Astronomy (DIFA), University of Bologna, Via Gobetti, 93/2, 40129 Bologna, Italy
³ Quasar Science Resources SL for ESA, European Space Astronomy Centre (ESAC), Science Operations Department, 28692 Villanueva de la Cañada, Madrid, Spain
⁴ Max Planck Institute für Extraterrestriche Physik, Giessenbachstrasse, 85748 Garching, Germany
⁵ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
⁶ Department of Physics, University of Rome ‘Tor Vergata’, Via della Ricerca Scientifica 1, 00133 Rome, Italy
⁷ INAF – Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monte Porzio Catone, (Roma), Italy
⁸ INFN – Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
⁹ Department of Astronomy, University of Maryland, College Park, MD 20742, USA
¹⁰ NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA
¹¹ INAF – Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere, 00133 Roma, Italy
¹² Department of Physics, Institute for Astrophysics and Computational Sciences, The Catholic University of America, Washington, DC 20064, USA
¹³ INAF – Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate, LC, Italy
¹⁴ Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, Trento 38123, Italy
¹⁵ Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424, USA
¹⁶ Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
¹⁷ Department of Physics, Informatics and Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy
¹⁸ Centro de Astrobiologia (CAB), CSIC-INTA, Departamento de Astrofisica, Cra. de Ajalvir Km. 4, 28850 Torrejon de Ardoz, Madrid, Spain
¹⁹ Joint Space-Science Institute, University of Maryland, College Park, MD 20742, USA

Received: 9 January 2024
Accepted: 17 June 2024

Abstract

Context. IRASF11119+3257 is an ultra-luminous infrared galaxy with a post-merger morphology, hosting a type-1 quasar at z = 0.189. It shows a prominent ultra-fast outflow (UFO) absorption feature (v_out ∼ 0.25c) in its 2013 Suzaku spectrum. This is the first system in which the energy released by the UFO was compared to that of the known galaxy-scale molecular outflow to investigate the mechanism driving active galactic nuclei (AGN) feedback.

Aims. In 2021, we obtained the first XMM-Newton long look of the target, coordinated with a simultaneous NuSTAR observation, with the goal of constraining the broad band continuum and the nuclear wind physical properties and energetics with an unprecedented accuracy.

Methods. The new high-quality data allowed us to clearly detect at a confidence level P > 99.8% multiple absorption features associated with the known UFO at the 9.1 and 11.0 keV rest frames. Furthermore, an emission plus absorption feature at 1.1 − 1.3 keV reveals the presence of a blueshifted P-Cygni profile in the soft band.

Results. We associate the two hard band features with blends of FeXXV and FeXXVI Heα-Lyα and Heβ-Lyβ line pairs and infer a large column (N_H ∼ 10²⁴ cm⁻²) of highly ionized (log ξ ∼ 5) gas outflowing at v_out = 0.27 ± 0.01c. The 1.3 keV absorption line can be associated with a blend of Fe and Ne transitions, produced by a lower column (N_H ∼ 3 × 10²¹ cm⁻²) and ionization (log ξ ∼ 2.6) gas component outflowing at the same speed. Using a radiative-transfer disk wind model to fit the highly ionized UFO, we derive a mass outflow rate comparable with the mass accretion rate and the Eddington limit (Ṁ_out = 4.25_−0.73^+1.11 M_⊙/yr, ∼1.6 Ṁ_acc and ∼1.0 Ṁ_Edd), and kinetic energy (Ė_kin = 1.21_−0.20^+0.32 L_bol and ∼0.7L_Edd) and momentum flux (Ṗ_out = 6.37_−1.09^+1.67 L_bol/c) among the highest reported in the literature. We measured an extremely low high-energy cutoff (E_cut ∼ 25 − 30 keV). This and several other cases in the literature suggest that a steep X-ray continuum may be related to the formation of powerful winds. We also analyzed the ionized [OIII] component of the large-scale outflow through optical spectroscopy and derived a large outflow velocity (v_out ∼ 3000 km/s) and energetics comparable with the large-scale molecular outflows. Finally, we observe a trend of decreasing outflow velocity from forbidden optical emission lines of decreasing ionization levels, interpreted as the outflow decelerating at large distances from the ionizing source.

Conclusions. The lack of a significant momentum boost between the nuclear UFO and the different phases of the large-scale outflow, observed in IRASF11119 and in a growing number of similar sources, can be explained by (i) a momentum-driven expansion, (ii) an inefficient coupling of the UFO with the host interstellar medium, or (iii) by repeated energy-driven expansion episodes with a low duty cycle, that average out on long timescales to produce the observed large-scale outflow.