The study of galactic bulbs reveals the formation of “waves”

Several observations made thanks to the Great Telescope in the Canary Islands have made it possible to understand the origin of the creation of certain types of galaxies that resemble the Milky Way. Like cities on Earth, their galactic bulges would form in two waves, the first consisting of old stars and the second of younger, slower expanding stars.

The study of the formation of galactic structures is an important field in astronomy, which makes it possible to understand construction of’Universe and ours The Milky Way. An international team of researchers from Center for Astrobiology (CAB) Spanish, in collaboration with the Department of Astrophysics in the Canary Islands, published an article in The Astrophysical Journal reports several observations galaxies, performed thanks to Gran Telescopio Canarias (GTC). The analysis of the results proved to be crucial: the galactic bulb of the monitored structures would be formed in two ” waves on different times. The first zone would consist ofstars eldest and the other ofstars younger.

Spectroscopy and redshift

To achieve this result, the team of researchers led by Dr. Luca Costantin data collected by the Shards program (Study for High-z Absorption Red and dead springs), performed using the Osiris instrument. The latter is an imager that makes it possible to produce a spectroscopy of several cosmic objects such as galaxies.

The spectroscopy performed on a galaxy makes it possible to break it down on the wavelength scale. Data received by CTM and Osiris made it possible to determine separation galactic bulbs in two parts thanks to red shift (Where red shift English). The farther a deep celestial object is from the observer, the more its spectral lines increase, causing a redshift. By calculating the wavelength and red shiftthat astronomers can decide the distance to a star or a distant structure exactly as well as his age.

Here, the observed galaxies have dents with different redshifts. One third of these built-up areas were formed by one red shift of 6.2. This corresponds to a primitive era of our universe, where the latter was only 5% of its current form and already 900 million years old. The remaining two-thirds were observed with a redshift of 1.3, closer to us and therefore newer, “only” 400 million years old.

An “urban” construction

To provide an easy-to-understand picture of their study, the CAB researchers (Center for Astrobiology) has compared this phenomenon with galactic formation in waves to the development of a city. As a large metropolis in XXand century, the galaxies would therefore have a “historical center”, which would have formed a periphery of younger stars. But beyond age, speed construction was also the subject of analysis for Dr. Costantin’s teams. The oldest areas of bulbs would have evolved very rapidly in a time frame of about 200 million years. The stars in the second wave of formation would have required some time pregnancy five times longer.

The galaxies we studied have the same thing morphology, components and masses corresponding to the Milky Way. It is therefore possible to find correlations between the studied structures. We can apply the development physical observed in these galaxies to the very history of our own system.adds Dr. Costantin.

This discovery should not signal the end of the observations of the galactic bulbs or the search for them galaxy formation. Understanding and dating these structures is an indisputable necessity for tracing the origin of the history of the universe and its construction.

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