INAF Arcetri Journal

Evidence of the fast acceleration of AGN-driven winds at kiloparsec scales

We provide evidence that outflows exhibit a regular radial velocity trend—initially constant or slightly decreasing, followed by rapid acceleration starting at approximately 1 kpc from the nucleus—despite the seemingly complex kinematics. The observed behaviour is consistent with current theoretical understanding of active galactic nucleus outflows, where a momentum-driven phase transitions to an energy-conserving phase beyond 1 kpc. The constant velocity of the momentum-driven wind is then rapidly accelerated following inefficient Compton cooling of post-shock material. The measured radial terminal velocities of the outflows are larger than the escape velocities from the host galaxies, confirming the role of outflows in shaping galaxy evolution as a manifestation of active galactic nucleus feedback.

Read the paper: https://www.nature.com/articles/s41550-025-02518-6

Authors: Cosimo Marconcini, Alessandro Marconi, Giovanni Cresci, Filippo Mannucci, Lorenzo Ulivi, Giacomo Venturi, Martina Scialpi, Giulia Tozzi, Francesco Belfiore, Elena Bertola, Elisa Cataldi, Avinanda Chakraborty, Quirino D’Amato, Enrico Di Teodoro, Anna Feltre et al.

WISDOM Project – XXII. A 5 per cent precision CO-dynamical supermassive black hole mass measurement in the galaxy NGC 383
In this study, ALMA observations of the CO line with very high spatial resolutions (about 10 pc) are used to measure the mass of the supermassive black hole (SMBH) at the center of the lenticular galaxy NGC 383. In particular, we studied the rotation of molecular gas in the nuclear regions of the galaxy and observed the so-called "Keplerial decay" due to the SMBH mass. The resulting mass measurement is one of the most precise ever obtained with this technique, reaching a precision of only 5%.

Read the paper: https://academic.oup.com/mnras/article/537/1/520/7951991

Co-authors: Ilaria Ruffa, Federico Lelli

Mapping radial abundance gradients with Gaia-ESO open clusters.
Evidence of recent gas accretion in the Milky Way disk

Over the past decade, Galactic archaeology has revolutionised our understanding of the Milky Way’s past, but the chemistry of its youngest populations remain largely unexplored. This study, a collaboration between the University of Bologna and INAF Arcetri and Trieste, sheds new light on the evolution of young (age < 5 Gyr) stellar populations using open clusters from the latest Gaia-ESO data. By refining data selection and comparing it with state-of-the-art chemical evolution models, we uncover an unexpected trend: the youngest clusters (age < 1 Gyr) show surprisingly low metallicity with respect to the older one, contradicting standard predictions of continuous chemical enrichment in the Milky Way disc. Our findings suggest a late, large-scale gas accretion event that diluted the Milky Way’s young disk, a scenario proposed using Gaia data in the solar neighbourhood, and now extended to the entire disc. These results mark a turning point in understanding the Milky Way’s recent evolution and open new avenues for future research on the chemical history of our Galaxy.

Read the paper: https://www.aanda.org/articles/aa/full_html/2024/10/aa51395-24/aa51395-24.html

Co-authors: Laura Magrini, Sofia Randich

Firenze | April 2025 | Contacts