Abstract
We investigate galactic-scale outflows in the redshift range 0.71 ≤ z
≤ 1.63, using 413 K-band selected galaxies observed in the
spectroscopic follow-up of the UKIDSS Ultra-Deep Survey (UDSz). The
galaxies have an average stellar mass of ˜109.5
M⊙ and span a wide range in rest-frame colours,
representing typical star-forming galaxies at this epoch. We stack the
spectra by various galaxy properties, including stellar mass, [O II]
equivalent width, star formation rate, specific star formation rate and
rest-frame spectral indices. We find that outflows are present in
virtually all spectral stacks, with velocities ranging from 100 to 1000
km s-1, indicating that large-scale outflowing winds are a
common property at these redshifts. The highest velocity outflows
(>500 km s-1) are found in galaxies with the highest
stellar masses and the youngest stellar populations. Our findings
suggest that high-velocity galactic outflows are mostly driven by
star-forming processes rather than active galactic nuclei, with implied
mass outflow rates comparable to the rates of star formation. Such
behaviour is consistent with models required to reproduce the
high-redshift mass-metallicity relation.
Original language | English |
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Pages (from-to) | 1406 |
Journal | Monthly Notices of the Royal Astronomical Society |
Publication status | Published - 1 May 2013 |
Keywords / Materials (for Non-textual outputs)
- galaxies: active
- galaxies: evolution
- quasars: general