Deep exposures with the Hubble Space Telescope (HST) have provided the primary evidence that star-forming galaxies were present in the first billion years of cosmic history. Through a sequence of ever-deeper HST images commencing with the Hubble Deep Field, the Ultra Deep Field (UDF) and further imaging with the near-infrared arm of the Wide Field Camera 3 (WFC3/IR), the frontiers of early galaxy formation have been pushed to redshifts beyond 8, corresponding to 650 million years after the Big Bang. Tentative claims have been made for sources at even earlier times. We present the first exciting results from the Ultra Deep Field 2012 - a new series of images totalling 128 orbits taken in the UDF with WFC3/IR during August and September this year. These extend our knowledge of this last frontier of cosmic history both in depth and, via the use of additional filters, in the fidelity of the sources found. In the key filters by which early galaxies are selected, the new survey termed UDF12 reaches nearly a magnitude deeper and the total infrared exposure is twice that of earlier data. Via these spectacularly deep images, we gain our first unambiguous view of the Universe beyond a redshift 8 and can clarify the abundance of sources to redshift 10 and beyond. Via the combination of deeper imaging and an improved strategy for eliminating foreground sources, the UDF12 takes us closer to the first generation of galaxies.
|Publication status||Published - 1 Jan 2013|
|Event||AAS, 221st Meeting of the American Astronomical Society - California, Long Beach, United Kingdom|
Duration: 6 Jan 2013 → 10 Jan 2013
|Conference||AAS, 221st Meeting of the American Astronomical Society|
|Period||6/01/13 → 10/01/13|