The first massive galaxies were formed during the first few billion of years of the Universe existence. However, the space was quite a violent place at that time, as it was ‘overcrowded’ with large entities according to the Big Bang theory. Therefore, galaxy collisions and mergers were quite regular. In any case, astronomers predict that some of those ancient or relic galaxies still exist and they could offer perfect opportunities for astronomers to study the characteristics of the early Universe.

Up to 0.1% of such primordial galaxies may still remain almost unchanged and more-or-less unaffected by strong cosmic disturbances according to the theoretical predictions. It is difficult to prove this theory since most of the oldest galaxies are located in the farthest regions of the universe, making all astronomical observations complicated. Despite this obstacle, the search for relic galaxies is ongoing and one candidate has been probably identified.

A joint team of astronomers from Spain and the USA have published their study at arXiv.org. They describe NGC1277, a galaxy, which is located relatively nearby galaxy and which in fact fulfills all the criteria to be considered a relic galaxy. NGC1277 is located in the Perseus cluster at a distance of 73 Mpc from our Solar System, and contains star populations, which are old enough to be formed at the dawn of the Universe.

The authors of the study have performed an analysis of the star formation history using a method called deep optical spectroscopy. They found that the age of stellar populations is distributed quite uniformly, with most of them being older than 10 billion years. Furthermore, no evidence of more recent star formation episodes have been determined, supporting the ‘relic galaxy’ assumption.

An analysis of the metallicity (a parameter of stars related to their age) also reveals a relatively small content of metals contained in the mass of the objects spanned by NGC1277. Higher metal content typically indicates younger stars. Meanwhile, it is not the case for NGC1277, where, according to the authors of the study, low metallicity dispersion also indicates that most of old stars in this object were formed in a very short period of time, almost resembling a single-burst event. In fact, it took less than few hundred million years to NGC1277 to form its mass – about 10 times faster than “normal sized” galaxies with equal mass.

By Alius Noreika, Source: Technology.org