VLT Smashes the Record of the Farthest Known Galaxy:

Redshift 10 Galaxy discovered at the Edge of the Dark Age

SN
   
Using the ISAAC near-infrared instrument on ESO's Very Large Telescope,
and the magnification effect of a gravitational lens, a team of French and
Swiss astronomers has found several faint galaxies believed to be the most
remote known.

Further spectroscopic studies of one of these candidates has provided a strong
case for what is now the new record holder - and by far - of the most distant
galaxy known in the Universe.

Named Abell 1835 IR1916, the newly discovered galaxy has a redshift of 10 
and is located about 13,230 million light-years away. It is therefore seen at a
time when the Universe was merely 470 million years young, that is, barely
3 percent of its current age.


Activities at Stockholm Observatory

The emphasis of the group on  observational  cosmology has up to now
mainly been on the study of clusters of  galaxies  at high and low  redshifts,
as well as their  relation to active  galactic  nuclei (AGN).  New
directions also  include  Ly-alpha emission and modeling of high redshift compact
galaxies and early  supernova  activity,  as well the use of supernovae
as cosmological  probes.

Based on different assumptions on the cosmic star formation rate and
cosmic dust extinction, we have predicted  the number of high redshift supernovae
of different types that should be observable with different telescopes,
such as the ESO Very Large Telescope (VLT) and the Next Generation Space
Telescope. In collaboration with astronomers from  Onsala Space Observatory,
Uppsala Astronomical Observatory, Lund Observatory and ESO, a project aiming at a
large high redshift supernovae survey have been initiated, and a large
programme has been accepted at the VLT with the VIMOS instrument. Using
repeated deep observations of two selected fields we expect to detect more
than 50 high redshift, supernovae, most of which will be core collapse
supernovae. Their redshifts will be estimated from multicolour photometry
of the host galaxies, employing the  photometric redshift technique. The
frequency of core collapse supernovae will be used as a probe of the
cosmic star formation rate at high redshift.

The study of the galaxy populations and luminosity functions in high
redshift galaxy clusters is continuing. The observational material comes from deep
multi-colour images obtained at the Nordic Optical Telescope, and from VLT
archive data. The photometric redshift technique has been employed to
significantly enhance the contrast in the subtraction of background
galaxies, which is normally the dominating source of uncertainty in determining the
properties of the galaxy populations in high redshift clusters.
With this method the galaxy populations and luminsity functions of 4 high
redshift clusters have for the first time been probed down to rest frame
absolute magnitudes as faint as M_B = -16.2 (z=0.30) and -17.7
(z=0.55). The project is continuing and has been extended
with deep K-band photometry and searches for emission line galaxies


Pressrelease  ESO.

Media contact:
Fil. Dr Göran Östlin
E-mail: goran@astro.su.se
Tel. 08-5537 8513

FRe