MUSE crowded field 3D spectroscopy in NGC 300

IV. Planetary nebula luminosity function^⋆

¹ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
e-mail: asoemitro@aip.de
² Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany
³ Department of Astronomy & Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA
⁴ Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802, USA
⁵ NSF’s NOIRLab, 950 N. Cherry Ave., Tucson, AZ 85719, USA
⁶ Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands

Received: 25 July 2022
Accepted: 5 January 2023

Abstract

Aims. We perform a deep survey of planetary nebulae (PNe) in the spiral galaxy NGC 300 to construct its planetary nebula luminosity function (PNLF). We aim to derive the distance using the PNLF and to probe the characteristics of the most luminous PNe.

Methods. We analysed 44 fields observed with MUSE at the VLT, covering a total area of ∼11 kpc². We find [O III]λ5007 sources using the differential emission line filter (DELF) technique. We identified PNe through spectral classification with the aid of the BPT diagram. The PNLF distance was derived using the maximum likelihood estimation technique. For the more luminous PNe, we also measured their extinction using the Balmer decrement. We estimated the luminosity and effective temperature of the central stars of the luminous PNe based on estimates of the excitation class and the assumption of optically thick nebulae.

Results. We identify 107 PNe and derive a most-likely distance modulus ${(m-M)}_0=26.{48}_{-0.26}^{+0.11}$ ($d=1.{98}_{-0.23}^{+0.10}$ Mpc). We find that the PNe at the PNLF cutoff exhibit relatively low extinction, with some high-extinction cases caused by local dust lanes. We present the lower limit luminosities and effective temperatures of the central stars for some of the brighter PNe. We also identify a few Type I PNe that come from a young population with progenitor masses > 2.5 M_⊙ but do not populate the PNLF cutoff.

Conclusions. The spatial resolution and spectral information of MUSE allow precise PN classification and photometry. These capabilities also enable us to resolve possible contamination by diffuse gas and dust, improving the accuracy of the PNLF distance to NGC 300.