The changing-look AGN NGC 1566 in quiescence with XMM-Newton: a nuclear starburst and an AGN competing in power?

ABSTRACT Star formation accretion on to the super massive black holes (SMBHs) and feedback processes link evolution of galaxies with their SMBHs. X-ray observations in imaging spectral regime have revealed be an important tool study connection between nuclear activity circumnuclear star nearby active galactic nuclei (AGN). diagnostics can lead disentangle, which is ionization mechanism central kiloparsecs AGN. In this paper, we investigate, by means XMM-Newton observations, emission changing-look AGN NGC 1566 during its quiescent state. European Photon Imaging Camera (EPIC) soft images show extended arm-like morphology. A detailed analysis high-resolution Reflection Grating Spectrometer (RGS) medium resolution EPIC spectra shows that material concentrated region not photoionization-dominated while presence collisionally ionized plasma needed explain observed features. inner (∼1.5 kpc), brightness gas comparable photoionized gas: hosts a luminous starburst whose up bright X-rays when quiescence.