Browse by author
Lookup NU author(s): Dr Christopher HarrisonORCiD
This is the final published version of an article that has been published in its final definitive form by Oxford University Press, 2019.
For re-use rights please refer to the publisher's terms and conditions.
© 2018 The Author(s).We present an analysis of the gas outflow energetics from KMOS observations of ∼529 mainsequence star-forming galaxies at z ∼1 using broad, underlying Hα and forbidden lines of [N II] and [S II]. Based on the stacked spectra for a sample with median star-formation rates and stellar masses of SFR = 7Ṁ yr-1 and M∗ = (1.0±0.1) × 1010Ṁ, respectively, we derive a typical mass outflow rate of Mwind = 1-4Ṁ yr-1 and a mass loading of Mwind / SFR = 0.2- 0.4. By comparing the kinetic energy in the wind with the energy released by supernovae, we estimate a coupling efficiency between the star formation and wind energetics of ∈ ∼ 0.03. The mass loading of the wind does not show a strong trend with star-formation rate over the range ∼2-20Ṁ yr-1, although we identify a trend with stellar mass such that dM/ dt / SFR ∝ M0.26±0.07. Finally, the line width of the broad Hα increases with disc circular velocity with a sub-linear scaling relation FWHMbroad ∝ v0.21 ± 0.05. As a result of this behaviour, in the lowest mass galaxies (M∗≲ 1010Ṁ), a significant fraction of the outflowing gas should have sufficient velocity to escape the gravitational potential of the halo whilst in the highest mass galaxies (M∗≲ 1010Ṁ) most of the gas will be retained, flowing back on to the galaxy disc at later times.
Author(s): Swinbank AM, Harrison CM, Tiley AL, Johnson HL, Smail I, Stott JP, Best PN, Bower RG, Bureau M, Bunker A, Cirasuolo M, Jarvis M, Magdis GE, Sharples RM, Sobral D
Publication type: Article
Publication status: Published
Journal: Monthly Notices of the Royal Astronomical Society
Print publication date: 01/07/2019
Online publication date: 09/05/2019
Acceptance date: 02/05/2019
Date deposited: 04/02/2020
ISSN (print): 0035-8711
ISSN (electronic): 1365-2966
Publisher: Oxford University Press
Altmetrics provided by Altmetric