Direct Evidence for Outflow Driven by Wolf-Rayet Stars in the Nearby Galaxy PGC44685
Qian Huang, Zhengyi Chen, Min Bao, Qiusheng Gu, Shiying Lu, Yulong Gao
astro-ph.GA
Submitted: 2026-07-03
Comments: 11 pages, 7 figures, Accepted for publication in The Astrophysical Journal
License: http://creativecommons.org/licenses/by/4.0/
The gist: Wolf--Rayet (WR) stars are evolved massive stars which can drive strong stellar winds, injecting energy and momentum into the interstellar medium (ISM).
Terminology
Abstract
Wolf--Rayet (WR) stars are evolved massive stars which can drive strong stellar winds, injecting energy and momentum into the interstellar medium (ISM). However, the geometry and kinematics of WR-dominated outflows, specially in low-metallicity environments, is still poorly constrained by observations. We present a spatially resolved spectroscopic study of a WR region in a nearby dwarf galaxy, PGC,44685, using high-resolution MEGARA IFU data from the Gran Telescopio Canarias (GTC). After decomposing the [O iii] lambda5007 emission line with narrow and broad components, we verify a WR-driven outflow with a velocity reaching up to 20, km,s-1 relative to the systemic velocity. By use of the velocity and flux of the [O iii] broad component, we estimate an outflow mass of (8.25 plus or minus 3.03) times10 cubed,M and a mass-loss rate of (9.47 plus or minus 3.48) times10-4,M, yr-1. The corresponding kinetic power and momentum injection rate are (4.77 plus or minus 1.77) times10 41, erg,s-1 and (8.20 plus or minus 3.02) times10 28, g,cm,s-2, respectively. The inferred low energy-loading efficiency (about0.35%), together with the low metallicity of the WR region (about0.1,Z), suggests that the system is observed in an early feedback phase in which stellar winds have not yet efficiently coupled their energy into the ISM. These results support the ability of WR feedback to shape the ISM on sub-kiloparsec scales, while these winds fail to launch galactic-scale outflows.
Sources
- A study of the interplay between ionized gas and star clusters in the central region of NGC 5253 with 2D spectroscopy
- Warm Ionized Gas Outflows in Active Galactic Nuclei: What Causes it?
- Witnessing the onset of stellar winds in Super-Luminous Supernova Hosts: implications for star-formation-driven outflows in low and high-redshift galaxies
- Models for WR and O Star Populations in Starbursts: New Developments and Applications to Large Samples of WR Galaxies
- CLusters in the Uv as EngineS (CLUES). II. Sub-kpc scale outflows driven by stellar feedback
Related papers
- Apparent Stability in Self-Gravitating Turbulence and the Evolution of Molecular Clouds
- Two sets of potential-density basis pairs for the study of radial perturbations in collisionless spherical stellar systems
- Constraining reionization-era Ly alpha escape with JELS-MUSE: a highly complete H alpha-selected sample at z about6.1
- Deriving volume density profiles of filaments from observed surface densities
- Little Red Dots and Supermassive Black Hole Seed Formation in Ultralight Dark Matter Halos
- MEGATRON: how the first stars can create an iron metallicity plateau in the smallest dwarf galaxies