Kinematics, Structure, and Mass Outflow Rates of Extreme Starburst Galactic Outflows

Authors

Serena Perrotta, University of California, San Diego
Alison L. Coil, University of California, San Diego
David S.N. Rupke, Rhodes College
Christy A. Tremonti, University of Wisconsin-Madison
Julie D. Davis, University of Wisconsin-Madison
Aleksandar M. Diamond-Stanic, Bates CollegeFollow
James E. Geach, University of Hertfordshire
Ryan C. Hickox, Dartmouth College
John Moustakas, Siena College
Gregory H. Rudnick, University of Kansas
Paul H. Sell, University of Florida
Cameren N. Swiggum, University of Wisconsin-Madison
Kelly E. Whalen, Dartmouth College

Publication Title

Astrophysical Journal

Document Type

Article

Department or Program

Physics and Astronomy

Publication Date

5-2023

Abstract

We present results on the properties of extreme gas outflows in massive (M * ∼ 1011 M ⊙), compact, starburst (star formation rate, SFR∼ 200 M ⊙ yr−1) galaxies at z = 0.4-0.7 with very high star formation surface densities (ΣSFR ∼ 2000 M ⊙ yr−1 kpc−2). Using optical Keck/HIRES spectroscopy of 14 HizEA starburst galaxies, we identify outflows with maximum velocities of 820-2860 km s−1. High-resolution spectroscopy allows us to measure precise column densities and covering fractions as a function of outflow velocity and characterize the kinematics and structure of the cool gas outflow phase (T ∼ 104 K). We find substantial variation in the absorption profiles, which likely reflects the complex morphology of inhomogeneously distributed, clumpy gas and the intricacy of the turbulent mixing layers between the cold and hot outflow phases. There is not a straightforward correlation between the bursts in the galaxies’ star formation histories and their wind absorption line profiles, as might naively be expected for starburst-driven winds. The lack of strong Mg ii absorption at the systemic velocity is likely an orientation effect, where the observations are down the axis of a blowout. We infer high mass outflow rates of ∼50-2200 M ⊙ yr−1, assuming a fiducial outflow size of 5 kpc, and mass loading factors of η ∼ 5 for most of the sample. While these values have high uncertainties, they suggest that starburst galaxies are capable of ejecting very large amounts of cool gas that will substantially impact their future evolution.

Comments

Original version is available from the publisher at: https://doi.org/10.3847/1538-4357/acc660

Recommended Citation

Perrotta, S., Coil, A. L., Rupke, D. S. N., Tremonti, C. A., Davis, J. D., Diamond-Stanic, A. M., Geach, J. E., Hickox, R. C., Moustakas, J., Rudnick, G. H., Sell, P. H., Swiggum, C. N., & Whalen, K. E. (2023). Kinematics, Structure, and Mass Outflow Rates of Extreme Starburst Galactic Outflows. The Astrophysical Journal, 949(1), 9–.

Copyright Note

© 2023. The Authors. Published by the American Astronomical Society.

Required Publisher's Statement

Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.