Extending the Dynamic Range of Galaxy Outflow Scaling Relations: Massive Compact Galaxies with Extreme Outflows
- Author(s)
- Julie D. Davis, Christy A. Tremonti, Cameren Swiggum, J. Moustakas, Aleksandar M. Diamond-Stanic, Alison L. Coil, J. E. Geach, Ryan C. Hickox, Serena Perrotta, Grayson Petter, Gregory H. Rudnick, David S. N. Rupke, Paul H. Sell, Kelly E. Whalen
- Abstract
We investigate galactic winds in the HizEA galaxies, a collection of 46 late-stage galaxy mergers at z = 0.4–0.8, with stellar masses of log(M∗/M⊙)=10.4--11.5, star formation rates (SFRs) of 20–500 M⊙ yr−1, and ultra-compact (a few 100 pc) central star-forming regions. We measure their gas kinematics using the Mg iiλλ 2796,2803 absorption lines in optical spectra from MMT, Magellan, and Keck. We find evidence of outflows in 90% of targets, with maximum outflow velocities of 550–3200 km s−1. We combine these data with ten samples from the literature to construct scaling relations for outflow velocity versus SFR, star formation surface density (ΣSFR), M*, and SFR/M*. The HizEA galaxies extend the dynamic range of the scaling relations by a factor of ∼2–4 in outflow velocity and an order of magnitude in SFR and ΣSFR. The ensemble scaling relations exhibit strong correlations between outflow velocity, SFR, SFR/R, and ΣSFR, and weaker correlations with M* and SFR/M*. The HizEA galaxies are mild outliers on the SFR and M* scaling relations, but they connect smoothly with more typical star-forming galaxies on plots of outflow velocity versus SFR/R and ΣSFR. These results provide further evidence that the HizEA galaxies' exceptional outflow velocities are a consequence of their extreme star formation conditions rather than hidden black hole activity, and they strengthen previous claims that ΣSFR is one of the most important properties governing the velocities of galactic winds.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- University of Wisconsin, Madison, Bates College, University of California, San Diego, Dartmouth College, University of Kansas, Rhodes College, University of Florida, Gainesville, Siena College, University of Hertfordshire
- Journal
- The Astrophysical Journal
- Volume
- 951
- No. of pages
- 33
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.3847/1538-4357/accbbf
- Publication date
- 07-2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/365e92d3-b042-4720-98e2-a828aa553d37