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arXiv · 2604.05665

Higher resolution optical spectra of $M_*<10^{10}~M_{\odot}$ galaxies reveal outflow signatures unresolved by the SDSS

B. Hagedorn·C. Cicone·C. Vignali·P. Severgnini·M. Pedani·M. Sarzi·A. Saintonge·M. Romano
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Abstract

Galactic outflows are predicted to be ubiquitous in low-mass galaxies, but observational evidence is lacking. Both a low signal-to-noise and a low spectral resolution can severely hamper the detection of galactic outflows, especially in small galaxies that have intrinsically narrow spectral lines. We obtained new, medium-high resolution (FWHM$_\mathrm{inst}\sim50-110$~km/s) optical spectra of 52 local star forming galaxies ($0.01 < z < 0.03$) with stellar masses $10^{8.5} 10^{-0.74}~\mathrm{M_{\odot}/yr}$). We estimate ionized gas mass outflow rates ranging from $\sim0.1-50\times10^{-3}~\mathrm{M_{\odot}/yr}$ (mean $\sim20\times10^{-3}~\mathrm{M_{\odot}/yr}$) and corresponding mass loading factors between 0.03 and 0.14 (mean $\sim0.07$) for the sample.

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B. Hagedorn, C. Cicone, C. Vignali, P. Severgnini, M. Pedani, M. Sarzi, A. Saintonge, M. Romano. 2026-04-07. Higher resolution optical spectra of $M_*<10^{10}~M_{\odot}$ galaxies reveal outflow signatures unresolved by the SDSS. https://doi.org/10.1051/0004-6361%2F202558663

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