A European team, led by Matt Lehnert (GEPI), has confirmed by spectroscopy, using the instrument SINFONI (ESO, VLT), the distance of the farthest galaxy ever. A redshift z=8.555 has been derived from the Lyman α hydrogen line (see Figure).
This galaxy, UDFy-38135539, was detected by the Hubble space telescope in 2009 as a candidate distant galaxy. The redshift derived by Lehnert et al. corresponds to a galaxy seen just 600 million years after the Big Bang. This early time is the era of reionisation, when the Universe is mainly filled with neutral opaque hydrogen that the first galaxies begin to ionize.
UDFy-38135539 is the most distant object ever confirmed by spectroscopic measurement. More details can be found in the corresponding ESO press release and the Letter in Nature : M. D. Lehnert, N. P. H. Nesvadba, J.-G. Cuby, A. M. Swinbank, S. Morris, B. Clément, C. J. Evans, M. N. Bremer, S. Basa, Nature 467, 940-942
- Part of the spectrum of UDFy-38135539 observed with SINFONI, around Lyman α shifted by z=8.555.