In article ,
"Richard D. Saam" writes:
Astronomers find most distant galaxy ever
http://arxiv.org/abs/1502.05399
at z=7.730

This is the most distant _spectroscopic confirmation_, based on a
line observed at 1062 nm and likely to be Lyman alpha.

There are _candidate galaxies_ at redshifts up to about 11. (I'm not
sure what the record is at the moment.) Spectroscopic confirmations
are difficult at high redshift not only because the candidate
galaxies are faint but also because the neutral intergalactic medium
is a strong absorber of Lyman alpha. There may soon be more
confirmations from ALMA based on the 158 micron [C II] line or
eventually from JWST based on [O II] or other UV or visible
lines. Probably most of the candidates will turn out to be at the
expected redshifts, but a few might be low-redshift objects with
peculiar (very red) spectral energy distributions.

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