Inferring the HII region escape fraction of ionizing photons from infrared emission lines in metal-poor star-forming dwarf galaxies

¹ Université Paris-Cité, Université Paris-Saclay, CEA, CNRS, AIM, 91191 Gif-sur-Yvette, France
e-mail: lise.ramambason@cea.fr
² Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, 106 91 Stockholm, Sweden
³ Physics Department, Elon University, 100 Campus Drive CB 2625, Elon, NC 27244, USA
⁴ Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
⁵ Instituto de Astronomía, Universidad Nacional Autónoma de México, AP 106, 22800 Ensenada, BC, Mexico
⁶ SOFIA Science Center, USRA, NASA Ames Research Center, M.S. N232-12, Moffett Field, CA 94035, USA
⁷ Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstrasse 12-14, 69120 Heidelberg, Germany
⁸ Institut fur Theoretische Astrophysik, Zentrum für Astronomie, Universität Heidelberg, 69120 Heidelberg, Germany
⁹ Sterrenkundig Observatorium, Ghent University, Krijgslaan 281 – S9, 9000 Ghent, Belgium
¹⁰ Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK

Received: 26 April 2022
Accepted: 11 July 2022

Abstract

Local metal-poor galaxies stand as ideal laboratories for probing the properties of the interstellar medium (ISM) in chemically unevolved conditions. Detailed studies of this primitive ISM can help gain insights into the physics of the first primordial galaxies that may be responsible for the reionization. Quantifying the ISM porosity to ionizing photons in nearby galaxies may improve our understanding of the mechanisms leading to Lyman continuum photon leakage from galaxies. The wealth of infrared (IR) tracers available in local galaxies and arising from different ISM phases allows us to constrain complex models in order to estimate physical quantities.