Bibcode
Livermore, R. C.; Jones, T.; Richard, J.; Bower, R. G.; Ellis, R. S.; Swinbank, A. M.; Rigby, J. R.; Smail, Ian; Arribas, S.; Rodriguez-Zaurin, J.; Colina, L.; Ebeling, H.; Crain, R. A.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 427, Issue 1, pp. 688-702.
Advertised on:
11
2012
Citations
104
Refereed citations
94
Description
We present Hubble Space Telescope/Wide Field Camera 3 narrow-band
imaging of the Hα emission in a sample of eight gravitationally
lensed galaxies at z = 1-1.5. The magnification caused by the foreground
clusters enables us to obtain a median source plane spatial resolution
of 360 pc, as well as providing magnifications in flux ranging from
˜10× to ˜50×. This enables us to identify
resolved star-forming H II regions at this epoch and therefore study
their Hα luminosity distributions for comparisons with equivalent
samples at z ˜ 2 and in the local Universe. We find evolution in
the both luminosity and surface brightness of H II regions with
redshift. The distribution of clump properties can be quantified with an
H II region luminosity function, which can be fit by a power law with an
exponential break at some cut-off, and we find that the cut-off evolves
with redshift. We therefore conclude that 'clumpy' galaxies are seen at
high redshift because of the evolution of the cut-off mass; the galaxies
themselves follow similar scaling relations to those at z = 0, but their
H II regions are larger and brighter and thus appear as clumps which
dominate the morphology of the galaxy. A simple theoretical argument
based on gas collapsing on scales of the Jeans mass in a marginally
unstable disc shows that the clumpy morphologies of high-z galaxies are
driven by the competing effects of higher gas fractions causing
perturbations on larger scales, partially compensated by higher
epicyclic frequencies which stabilize the disc.
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Starbursts in Galaxies GEFE
Starsbursts play a key role in the cosmic evolution of galaxies, and thus in the star formation (SF) history of the universe, the production of metals, and the feedback coupling galaxies with the cosmic web. Extreme SF conditions prevail early on during the formation of the first stars and galaxies, therefore, the starburst phenomenon constitutes a
Casiana
Muñoz Tuñón