The MUSE view of the Sculptor galaxy: Survey overview and the luminosity function of planetary nebulae

¹ European Southern Observatory (ESO), Alonso de Córdova 3107, Casilla 19, Santiago 19001, Chile
² Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, 69120 Heidelberg, Germany
³ Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA
⁴ Center for Cosmology and Astroparticle Physics, 191 West Woodruff Avenue, Columbus, OH 43210, USA
⁵ European Southern Observatory, Karl-Schwarzschild Straße 2, D-85748 Garching bei München, Germany
⁶ Univ Lyon, Univ Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France
⁷ INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50157 Firenze, Italy
⁸ Finnish Centre for Astronomy with ESO, (FINCA), University of Turku, FI-20014 Turku, Finland
⁹ Tuorla Observatory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
¹⁰ Turku Collegium for Science, Medicine and Technology, University of Turku, FI-20014 Turku, Finland
¹¹ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
¹² International Centre for Radio Astronomy Research, University of Western Australia, 7 Fairway, Crawley, 6009 WA, Australia
¹³ Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
¹⁴ Dipartimento di Fisica e Astronomia ‘G. Galilei’, Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova, Italy
¹⁵ Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
¹⁶ Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA
¹⁷ Departamento de Astronomía, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago, Chile
¹⁸ Department of Astronomy, University of Maryland, College Park, MD 20742, USA
¹⁹ Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA
²⁰ Instituto de Astronomía, Universidad Nacional Autónoma de México, Ap. 70-264, 04510 CDMX, Mexico
²¹ Department of Physics, University of Connecticut, 196A Auditorium Road, Storrs, CT 06269, USA
²² Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany
²³ Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
²⁴ Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
²⁵ Elizabeth S. and Richard M. Cashin Fellow at the Radcliffe Institute for Advanced Studies at Harvard University, 10 Garden Street, Cambridge, MA 02138, USA
²⁶ Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
²⁷ Sub-department of Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK

^⋆ Corresponding author: econgiu@eso.org

Received: 14 February 2025
Accepted: 10 June 2025

Abstract

The Sculptor galaxy, NGC 253, is the southern massive star-forming disk galaxy that is closest to the Milky Way. We present a new 103-pointing MUSE mosaic of this galaxy that covers most of its star-forming disk up to 0.75 × R₂₅. With an area of ∼20 × 5 arcmin² (∼20 × 5 kpc², projected) and a physical resolution of ∼15 pc, this mosaic constitutes one of the largest integral field spectroscopy surveys with the highest physical resolution of any star-forming galaxy to date. We exploited the mosaic to identify a sample of ∼500 planetary nebulae (the sample is ∼20 times larger than in previous studies) to build the planetary nebula luminosity function (PNLF) and obtain a new estimate of the distance to NGC 253. The value we obtained is 17% higher than the estimates returned by other reliable measurements, which were mainly obtained via the top of the red giant branch method. The PNLF also varies between the centre (r < 4 kpc) and the disk of the galaxy. The distance derived from the PNLF of the outer disk is comparable to that of the full sample, while the PNLF of the centre returns a distance that is larger by ∼0.9 Mpc. Our analysis suggests that extinction related to the dust-rich interstellar medium and edge-on view of the galaxy (the average E(B−V) across the disk is ∼0.35 mag) plays a major role in explaining both the larger distance recovered from the full PNLF and the difference between the PNLFs in the centre and the disk.