Physical Properties of Massive Compact Starburst Galaxies with Extreme Outflows

Authors

Serena Perrotta, University of California, San Diego
Erin R. George, University of California, San Diego
Alison L. Coil, University of California, San Diego
Christy A. Tremonti, University of Wisconsin-Madison
David S.N. Rupke, Rhodes College
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
Grayson C. Petter, Dartmouth 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

12-2021

Abstract

We present results on the nature of extreme ejective feedback episodes and the physical conditions of a population of massive (M * ∼ 1011 M ⊙), compact starburst galaxies at z = 0.4–0.7. We use data from Keck/NIRSPEC, SDSS, Gemini/GMOS, MMT, and Magellan/MagE to measure rest-frame optical and near-IR spectra of 14 starburst galaxies with extremely high star formation rate surface densities (mean ΣSFR ∼ 2000 M ⊙ yr−1 kpc−2) and powerful galactic outflows (maximum speeds v 98 ∼ 1000–3000 km s−1). Our unique data set includes an ensemble of both emission ([O ii] λλ3726,3729, Hβ, [O iii] λλ4959,5007, Hα, [N ii] λλ6549,6585, and [S ii] λλ6716,6731) and absorption (Mg ii λλ2796,2803, and Fe ii λ2586) lines that allow us to investigate the kinematics of the cool gas phase (T ∼ 104 K) in the outflows. Employing a suite of line ratio diagnostic diagrams, we find that the central starbursts are characterized by high electron densities (median n e ∼ 530 cm−3), and high metallicity (solar or supersolar). We show that the outflows are most likely driven by stellar feedback emerging from the extreme central starburst, rather than by an AGN. We also present multiple intriguing observational signatures suggesting that these galaxies may have substantial Lyman continuum (LyC) photon leakage, including weak [S ii] nebular emission lines. Our results imply that these galaxies may be captured in a short-lived phase of extreme star formation and feedback where much of their gas is violently blown out by powerful outflows that open up channels for LyC photons to escape.

Comments

Original version is available from the publisher at: https://doi.org/10.3847/1538-4357/ac2fa4

Recommended Citation

Perrotta, S., George, E. R., Coil, A. L., Tremonti, C. A., Rupke, D. S. N., Davis, J. D., Diamond-Stanic, A. M., Geach, J. E., Hickox, R. C., Moustakas, J., Petter, G. C., Rudnick, G. H., Sell, P. H., Swiggum, C. N., & Whalen, K. E. (2021). Physical Properties of Massive Compact Starburst Galaxies with Extreme Outflows. The Astrophysical Journal, 923(2), 275–.

Copyright Note

© 2021. The Author(s). 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.