A deep study of the spiral galaxy W2246f

¹ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
² Instituto de Astronomía y Ciencias Planetarias, Universidad de Atacama, Avenida Copayapu 485, 1530000, Copiapó, Chile
³ Universidad Nacional Autónoma de México, Instituto de Astronomía, AP 106, Ensenada, 22800, BC, Mexico
⁴ Millenium Nucleus for Galaxies (MINGAL)
⁵ Institute of Astrophysics, Foundation for Research and Technology Hellas (FORTH), Heraklion, 70013, Greece
⁶ School of Sciences, European University Cyprus, Diogenes Street, Engomi, 1516, Nicosia, Cyprus
⁷ Centro de Astrobiología (CAB), CSIC-INTA, Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850, Madrid, Spain
⁸ Department of Physics, Northwestern College, 101 7th St SW, Orange City, IA, 51041, USA
⁹ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, 100871, People’s Republic of China
¹⁰ National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing, 100101, China
¹¹ Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing, 102206, China
¹² School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, 100049, China

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 7 April 2026
Accepted: 27 May 2026

Abstract

Aims. In this era of large surveys and statistical studies of galaxies, the beauty in the details of individual galaxies is often lost. In this paper we present a deep study of the spiral galaxy W2246f with MUSE, exploring the spatially resolved stellar and ionised gas properties to understand how it formed and evolved over time. The unusually deep observations of this galaxy with MUSE give us a rare opportunity to study this phenomenon with a better spatial resolution than can normally be achieved with the current IFU surveys of galaxies at a similar redshift (z ∼ 0.09).

Methods. We analyse the stellar and gas kinematics, as well as the spatially resolved stellar populations and gas properties, including gas metallicity and the dominant ionisation sources. The derived properties include the stellar mass, radial profiles of luminosity- and mass-weighted mean ages and metallicities, and ionised gas characteristics such as E(B − V), Hα extinction, dust-corrected Hα flux, oxygen abundance using the O3N2 calibrator, Hα luminosity, and the Hα-based star formation rate.

Results. Analysis of the stellar populations revealed a negative metallicity gradient, and the mass-weighted ages showed uniformly flat ages across the disc while the luminosity-weighted ages show a negative gradient. We find that the gas metallicity and star formation rate density also drop in the central region of the galaxy where the older luminosity-weighted stellar populations are found. Analysis of the WHAN and WHaD diagrams reveal that in fact the central region is retired, while the rest of the disc is star-forming.

Conclusions. We conclude that W2246f is a nice example of a central low-ionisation emission-line region (cLIER) galaxy, where the central kpc is dominated by old, metal-poor stars with little star formation. The cLIER emission is primarily powered by hot evolved stars, while the rest of the disc displays ongoing star formation. These findings are consistent with a scenario of inside-out quenching.