I was impressed by the beauty of the appearance of galaxy clusters in the Universe


Tadayuki KODAMA

1.What kind of the research are you doing?

At present, I am particularly interested in the following two subjects in extra galactic astronomy. I tackle these problems primarily using Subaru and ALMA telescopes.

(1) Formation and evolution of porto-clusters of galaxies:
Galaxies often exist as groups or clusters. How are those systems formed in the Universe and how are the galaxies therein formed and evolve under the effects of surrounding environments? We search for progenitors of galaxy clusters further and further away from us in order to watch their formation in action in the early Universe. It is also known that present-day clusters are dominated by quiescent elliptical type galaxies, and we also investigate the origin of such cosmic habitat segregation.

(2) Formation of massive galaxies in the early Universe:
In the early Universe, it is predicted that small mass galaxies were formed first and they subsequently merge together and grew to larger systems with time. This means that if we find massive galaxies in the early Universe when the cosmic age is still young, we can put strong constraints on the theory of galaxy formation. Galaxy formation must have started at very early epoch in the Universe and have proceeded in an accelerated manner. We have developed our unique filters on near-infrared instruments to search for the most distant massive galaxies. We expect to find such objects in proto-clusters, as the galaxy formation is expected to be accelerated in high density environments.

2.What is the reason for starting your study?

First of all, I was impressed by the beauty of the appearance of galaxy clusters in the Universe, which motivated me to study this type of cosmic objects as my lifework. Galaxies living in such large cities of the Universe are different from our Milky Way galaxy both in shape and other properties. What does make this diversity? I also had a simple, naive question that is how a big mature galaxy like our Milky Way galaxy is first formed in the Universe. This is related to the origin of ourselves. In order to solve these fundamental questions, I have been motivated to go back in time using large telescopes and see directly with my eyes what was actually happening in the past.

3.Message for prospective students

Astronomy is the ultimate science that tries to reveal the physical origins and processes in the Universe. Moreover, astronomy is the ultimate archaeology that can directly take us back in time by looking into further and further away from us. That aims to reveal the entire history of the Universe over the past 13.8 billion years. Why not look up from our world on the earth into the deep cosmos with full of stars, and hear signals coming from the past even more than 10 billion years ago, and think how our galaxy, the solar system, the earth, and eventually ourselves are formed and why they can all exist in the Universe.