Michael D. Gladders, Jane R. Rigby, Keren Sharon, Eva Wuyts, Louis E. Abramson, Hakon Dahle, S. E. Persson, Andrew J. Monson, Daniel D. Kelson, Dominic J. Benford, David Murphy, Matthew B. Bayliss, Keely D. Finkelstein, Benjamin P. Koester, Alissa Bans, Eric J. Baxter, Jennifer E. Helsby
We present the discovery and a detailed multi-wavelength study of a
strongly-lensed luminous infrared galaxy at z=0.816. Unlike most known lensed
galaxies discovered at optical or near-infrared wavelengths, this lensed source
is red, which the data presented here demonstrate is due to ongoing dusty star
formation. The overall lensing magnification (a factor of 17) facilitates
observations from the blue optical through to 500 micron, fully capturing both
the stellar photospheric emission as well as the re-processed thermal dust
emission. We also present optical and near-IR spectroscopy. These extensive
data show that this lensed galaxy is in many ways typical of IR-detected
sources at z~1, with both a total luminosity and size in accordance with other
(albeit much less detailed) measurements in samples of galaxies observed in
deep fields with the Spitzer telescope. Its far-infrared spectral energy
distribution is well--fit by local templates that are an order of magnitude
less luminous than the lensed galaxy; local templates of comparable luminosity
are too hot to fit. Its size (D~7 kpc) is much larger than local luminous
infrared galaxies, but in line with sizes observed for such galaxies at z~1.
The star formation appears uniform across this spatial scale. Thus, this lensed
galaxy, which appears representative of vigorously star--forming z~1 galaxies,
is forming stars in a fundamentally different mode than is seen at z~0.
View original:
http://arxiv.org/abs/1202.5269
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