MUSE view of PDS 456: Kiloparsec-scale wind, extended ionized gas, and close environment

¹ Dipartimento di Fisica “G. Occhialini”, Università degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
e-mail: andrea.travascio@unimib.it
² INAF – Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy
³ INAF – Osservatorio Astronomico di Roma, Via di Frascati 33, 00040 Monteporzio Catone Rome, Italy
⁴ Dipartimento di Fisica, Universitá di Trieste, Sezione di Astronomia, Via G.B. Tiepolo 11, 34131 Trieste, Italy
⁵ INAF – Osservatorio Astrofisco di Arcetri, Largo E. Fermi 5, 50127 Firenze, Italy
⁶ Centro de Astrobiología (CAB), CSIC–INTA, Cra. de Ajalvir Km. 4, 28850 Torrejón de Ardoz, Madrid, Spain
⁷ INAF – Istituto di Astrofisica Spaziale e Fisica cosmica Milano, Via Alfonso Corti 12, 20133 Milano, Italy
⁸ Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
⁹ Institute of Theoretical Astrophysics, University of Oslo, PO Box 1029 Blindern, 0315 Oslo, Norway
¹⁰ Dipartimento di Astronomia e Scienza dello Spazio, Universià degli Studi di Firenze, Largo E. Fermi 2, 50125 Firenze, Italy
¹¹ Center for Physical Sciences and Technology, Saulėtekio al. 3, Vilnius 10257, Lithuania
¹² Astronomical Observatory, Vilnius University, Saulėtekio al. 3, Vilnius 10257, Lithuania
¹³ Dipartimento di Fisica e Astronomia “Augusto Righi”, Università degli Studi di Bologna, Via P. Gobetti, 93/2, 40129 Bologna, Italy
¹⁴ INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti, 93/3, 40129 Bologna, Italy
¹⁵ INAF – Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Caveliere 100, 00133 Roma, Italy
¹⁶ European Southern Observatory, Karl-Schwarzschild-Strasse 2, Garching bei München, Germany
¹⁷ Instituto de Astrofísica de Canarias, Calle Vía Láctea, s/n, 38205 La Laguna, Tenerife, Spain
¹⁸ Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
¹⁹ Dept. of Physics, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
²⁰ Dept. of Astronomy, University of Maryland, College Park, MD 20742, USA
²¹ NASA – Goddard Space Flight Center, Code 662, Greenbelt, MD 20771, USA
²² INFN – Roma Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Rome, Italy

Received: 10 January 2024
Accepted: 24 March 2024

Abstract

PDS 456 is the most luminous (L_bol ∼ 10⁴⁷ erg s⁻¹) radio-quiet quasar at z < 0.3 and can be regarded as a local counterpart of the powerful quasars shining at Cosmic Noon. It hosts a strong nuclear X-ray ultra-fast (∼0.3c) outflow, and a massive and clumpy CO (3–2) molecular outflow extending up to ∼5 kpc from the nucleus. We analyzed the first MUSE Wide Field Mode (WFM) and Adaptive-Optics Narrow Field Mode (AO-NFM) optical integral field spectroscopic observations of PDS456. The AO-NFM observations provide an unprecedented spatial resolution, reaching up to ∼280 pc. Our findings reveal a complex circumgalactic medium around PDS 456, extending to a maximum projected size of ≈46 kpc. This includes a reservoir of gas with a mass of ∼10⁷ − 10⁸ M_⊙, along with eight companion galaxies and a multi-phase outflow. WFM and NFM MUSE data reveal an outflow on a large scale (≈12 kpc from the quasar) in [O III], and on smaller scales (within 3 kpc) with higher resolution (about 280 pc) in Hα, respectively. The [O III] outflow mass rate is 2.3 ± 0.2 M_⊙ yr⁻¹ which is significantly lower than those typically found in other luminous quasars. Remarkably, the Hα outflow shows a similar scale, morphology, and kinematics to the CO (3–2) molecular outflow, with the latter dominating in terms of kinetic energy and mass outflow rate by two and one orders of magnitude, respectively. Our results therefore indicate that mergers, powerful active galactic nucleus (AGN) activity, and feedback through AGN-driven winds collectively contribute to shaping the host galaxy evolution of PDS 456, and likely that of similar objects at the brightest end of the AGN luminosity function across all redshifts. Moreover, the finding that the momentum boost of the total outflow deviates from the expected energy-conserving expansion for large-scale outflows highlights the need of novel AGN-driven outflow models to comprehensively interpret these phenomena.