Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052

¹ KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, 106 91 Stockholm, Sweden
e-mail: falocco@kth.se
² National Centre for Radio Astrophysics, TIFR, Pune University Campus, Post Bag 3, Pune 411 007, India

Received: 16 January 2020
Accepted: 5 April 2020

Abstract

Aims. We aim to determine the properties of the central region of NGC 1052 using X-ray and radio data. NGC 1052 (z = 0.005) has been investigated for decades in different energy bands and shows radio lobes and a low-luminosity active galactic nucleus.

Methods. We used X-ray images from Chandra and radio images from Very Large Array to explore the morphology of the central area. We also studied the spectra of the nucleus and the surrounding region using observations from Chandra and XMM-Newton.

Results. We find diffuse soft X-ray radiation and hot-spots along the radio lobes. The spectrum of the circum-nuclear region is well described by a thermal plasma (T ∼ 0.6 keV) and a power law with photon index Γ ∼ 2.3. The nucleus shows a hard power law (Γ ∼ 1.4) modified by complex absorption. A narrow iron Kα line is also clearly detected in all observations, but there is no evidence for relativistic reflection.

Conclusions. The extended emission is consistent with originating from extended jets and from jet-triggered shocks in the surrounding medium. The hard power-law emission from the nucleus and the lack of relativistic reflection supports the scenario of inefficient accretion in an advection-dominated accretion flow.