Researchers involved with AEGIS have carefully selected 544 distant galaxies to learn how galaxies take their mature forms.
Galaxies are born small and eventually grow when they start taking a mature form.
The galaxies that are examined weigh in with redshifts in the range of 0.1 to 1.2. This translates the look back time to almost 8 billion years. This means that what we are seeing today is the process of galaxy formation or galaxies in their adolescence.
These new galaxies are more deformed then the nearby ones. But it eventually turns out a relation between a galaxy’s mass and the orbital speed of its stars and gas is consistent over different types of galaxies and even after billions of years of galaxy formation these things remain the same.
If you put it in simple words the more massive a galaxy is the faster the stars and gas inside it moves.
This analysis also includes a dispersion component that adds to the disks rotational a way to analyze its distorted internal movements.
This new study can be taken as an extension of Tully-Fisher relation that was developed some 30 years ago for nearby galaxies.
This relation provides a relation between a galaxy’s luminosity and its rotational speed. Now this latest research is also making a relation between a galaxy’s mass and its rotational speed.
Galaxies are broadly classified into spirals and remnants of collisions, though we also have a third kind that involves elliptical galaxy. In the third case a different law is observed, here the more massive the galaxy the faster the random motion of its stars. The new work however bridges the gap between both the laws and incorporates both rotation and random velocity.
Researchers have to consider the elliptical galaxies into the scenario as they are largely free of star formation and have an older dying population of stars than the spiral galaxies which show blue light and star formation is taking place in them.
Researchers have also commented that:
‘Galaxies began life as quantum fluctuations-tiny density fluctuations that created the seeds for the later coagulation of structure in the universe. When gravity took over, those seeds made galaxies, and we think that process is reflected in the Tully-Fisher relation.’
According to this new research on galaxies as diverse as these are more regular than we thought them to be and all galaxies emerge from the same set of principles. This formation research can also date back to the Big Bang when it all started.
Via: spaceref
