Newly discovered mature galaxy cluster, revised big bang theory?
Image Credit European Southern Observatory (ESO)
Scientists working from the European Southern Observatory (ESO) in Chile have recently discovered the furthest mature cluster of galaxies away from us which we can still see. From the available data, it seems that our ideas about the 'Big Bang' when the universe was created might have to be adapted.
The apparent maturity of this recently discovered cluster of galaxies was not at all what scientists were expecting. It is quite unusual to discover great clusters of galaxies at any rate. But most of the distant clusters of galaxies that have been recorded are young and still in the formation process, whereas this particular cluster seems to be developing passively, not actively.
Dr Raphael Gobat of the Laboratoire Paris-AIM-Saclay in France and his international team discovered a cluster of galaxies called CL J1449+0856 which seems to be from the earlier time of the Big Bang, at about 1/4th of the age the universe is thought to be now, actually about 3 billion years 'young', but even so it seems to be settled down.
If the Big Bang theory is correct, this cluster should be young and still forming stars. But it is sending out X-rays on a frequency which shows a hot cloud of gas trapped in between the galaxies, which is a typical sign of a mature galaxy. A young galaxy would not have had the time to trap enough gas to cause this signature. Both the NASA/ESA Hubble telescope and ESO's Very Large Telescope, or VLT, were used to observe the cluster. The data gathered thus far seem to indicate that the stars in the galaxies are at least a billion years old.
The cluster was first detected by the Spitzer telescope as a distant group of red objects. The distance to this particular cluster was measured by splitting up the light coming from the object (with a spectrograph) into its component colors. By measuring the redshift, which is how much the red light on the scale has shifted compared to now (the wavelength of the light increases as the universe expands), scientists can measure how 'old' the light is that is coming off the object, determining its age by the speed of light, which is about 300 million meters/second. More research is obviously needed to determine whether this mature cluster is a 'rare occurrence' or not.
Further reading: The Most Distant Mature Galaxy Cluster