ESO's Multi Unit Spectroscopic Explorer (MUSE) instrument, which is mounted on the Very Large Telescope based in the Paranal Observatory, Chile, has been focusing in on a tiny patch in the night sky previously featured in Hubble's Deep Field South image (HDF-S). After only 27 hours of continuous observation, the cutting edge instrument has captured detailed measurements of more galaxies with more detail than ever before.
The regions of space captured in previous deep field images have been observed by multiple instruments, including Hubble and NASA's Chandra X-ray Observatory. However, even the combined data returned by these legendary platforms cannot match the depth of data harvested by MUSE.
Furthermore, whilst Hubble had to observe the tiny patch of sky for 10 days in order to compile HDF-S, MUSE required only 27 hours to capture a set of images containing more data than that of the legendary telescope.
"After just a few hours of observations at the telescope, we had a quick look at the data and found many galaxies – it was very encouraging," states Rolan Bacon, principle investigator of the MUSE instrument. "When we got back to Europe we started exploring the data in more detail. It was like fishing in deep water and each new catch generated a lot of excitement and discussion of the species we were finding."
However, the instrument's main strength is derived from its ability to combine a deep field image with an advanced light spectrum reading. Each pixel of a MUSE image contains around 90,000 spectra, an analysis of which allows astronomers to discern the distance, make up, and internal motion of the astronomical object captured in the pixel.
An analysis of the MUSE images has already allowed astronomers to discern the distances of 189 galaxies (some of which dated from a time when the universe was less than a billion years of age), including over 20 galaxies that were too faint to be captured by Hubble in the original HDF-S.
"Now that we have demonstrated MUSE’s unique capabilities for exploring the deep Universe, we are going to look at other deep fields, such as the Hubble Ultra Deep field," states Bacon. "We will be able to study thousands of galaxies and to discover new extremely faint and distant galaxies. These small infant galaxies, seen as they were more than 10 billion years in the past, gradually grew up to become galaxies like the Milky Way that we see today."
A paper detailing the findings has been published in the online journal Astronomy & Astrophysics.