2025MNRAS.538.1628B

We study the bulge-disc components and stellar mass distribution in the fast-rotating, highly massive spiral galaxy 2MASX J23453268-0449256, which is distinguished by extraordinary radio jets extending to Mpc scales. Using high-resolution multiwavelength Hubble Space Telescope (HST) observations and multiparameter panchromatic spectral energy distribution (SED) fitting, we derive estimates of key properties, such as the star formation rate, total baryonic mass in stars, and the characteristics of warm dust. Our findings, validated at a spatial resolution of approximately 100 pc, reveal a pseudo-bulge rather than a classical bulge, as well as a small nuclear bar and resonant ring, challenging traditional models of galaxy formation. Furthermore, the absence of tidal debris and the highly symmetric spiral arms within a rotationally supported stellar disc suggest a peaceful co-evolution of the galactic disc and its central supermassive black hole (SMBH). Notably, the galaxy exhibits suppressed star formation in its central region, which may be influenced by feedback from the central accreting SMBH, producing powerful radio jets. Detailed multiwavelength studies of potential star-forming gas show that while hot X-ray gas cools in the galaxy's halo, new stars do not form in the centre, likely due to this feedback. This study raises important questions about the efficient fuelling and sustained collimated jet activity in J2345-0449, highlighting the need for a better understanding of the central black hole's properties. The exceptional rarity of galaxies like 2MASX J23453268-0449256 presents intriguing challenges in uncovering the physical processes behind their unique characteristics.