High-velocity Outflows in [O <scp>III</scp> ] Emitters at 2.5 < <i>z</i> < 9 from JWST NIRSpec Medium-resolution Spectroscopy
R. L. Cooper, K. I. Caputi, Edoardo Iani, Pierluigi Rinaldi, G. Desprez, Rafael Navarro-Carrera
Abstract
Abstract We identify galaxies hosting ionised-gas high-velocity outflows from the complete sample of medium-resolution (R1000) JWST/NIRSpec MSA spectroscopy taken as part of the JWST Advanced Deep Extragalactic Survey. From a total sample of 1087 [O III ] 5007 emitters we identify 40 galaxies with a blue-side broadened [O III ] 5007 line at 2.5 < z < 9. Of these, 34 are strong outflow candidates while 6 sources exhibit broadening potentially driven by rotating clumps. Our outflow candidate sample is mainly composed of star-forming galaxies, including ∼65% starbursts, which span the stellar mass range 7.5 < log 10 ( M * / M ⊙ ) < 11.0. It also includes two candidate type-2 active galactic nuclei and a “little red dot.” We report a median outflow velocity of 531 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow/> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>159</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>146</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> km s −1 and an overall incidence rate of 3.4%. These values are significantly higher and lower, respectively, than recent similar works, which we accredit to the limiting resolution of the R1000 spectroscopy and a stricter outflow selection criterion. We find no correlation between the outflow velocity and the galaxy stellar mass or star formation rate. The median ratio between outflow velocity and escape velocity is 0.77 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow/> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.32</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.36</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> , indicating that most outflows cannot escape the galaxy gravitational potentials. We do find an anti-correlation between mass loading factor and stellar mass up to M * ≈ 10 10 M ⊙ , with most lowest-stellar-mass ( M * < 10 9 M ⊙ ) galaxies reaching values well above unity, as is the case for local starburst galaxies.