The impact of spiral arms on the star formation life cycle

¹ Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany
² Cosmic Origins Of Life (COOL) Research DAO, https://coolresearch.io
³ Technical University of Munich, School of Engineering and Design, Department of Aerospace and Geodesy, Chair of Remote Sensing Technology, Arcisstr. 21, 80333 Munich, Germany
⁴ Observatorio Astronómico Nacional (IGN), C/Alfonso XII, 3, E-28014 Madrid, Spain
⁵ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, 06000 Nice, France
⁶ Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA
⁷ Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, 02138 Cambridge, MA, USA
⁸ Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia
⁹ IRAP, OMP, Université de Toulouse, 9 Av. du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France
¹⁰ Kavli Institute for Particle Astrophysics & Cosmology, Stanford University, CA 94305, USA
¹¹ Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF, UK
¹² Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent, Belgium
¹³ Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
¹⁴ Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, 04510 México D. F., Mexico
¹⁵ European Southern Observatory, Karl-Schwarzschild Straße 2, D-85748 Garching bei München, Germany
¹⁶ IRAM, 300 rue de la Piscine, 38400 Saint Martin d’Hères, France
¹⁷ LUX, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, 75014 Paris, France
¹⁸ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
¹⁹ SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS, UK
²⁰ Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544, USA
²¹ Sub-department of Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK

^⋆ Corresponding author: andrea.romanelli@stud.uni-heidelberg.de

Received: 24 January 2025
Accepted: 9 May 2025

Abstract

The matter cycle between gas clouds and stars in galaxies plays a crucial role in regulating galaxy evolution through feedback mechanisms. In turn, the local and global galactic environments shape the interstellar medium and provide the initial conditions for star formation, potentially affecting the properties of this small-scale matter cycle. In particular, spiral arms have been proposed to play a pivotal role in the star formation life cycle, by enhancing the gas density and triggering star formation. However, their exact role is still debated. In this study, we investigated the role of spiral arms in the giant molecular cloud evolutionary life cycle and on the star formation process in a sample of 22 nearby spiral galaxies from the PHANGS survey. We measured the cloud lifetime, the feedback timescale, the typical distance between independent regions, and the star formation efficiency in spiral arms and inter-arm regions separately. We find that the distributions of the cloud lifetime as well as the feedback timescale are similar in both environments. This result suggests that spiral arms are unlikely to play a dominant role in triggering star formation. By contrast, the star formation efficiency appears to be slightly higher in inter-arm regions compared to spiral arms.