An international team of astronomers, led by Yoichi Tamurafrom Nagoya University, managed to capture high resolution images of an ancient galaxy that existed just 600 million years after the big Bang.
These radio images, obtained with the SOUL telescope (Atacama Large Millimeter/submillimeter Array in Chile), shed light on structures never seen before formed by the interaction of dark and emission nebulae.
Observations paint a captivating tapestry in which these nebulae merge to form form a gigantic cavity resembling a “superbubble”, in the words of ALMA’s presentation of the discovery. This super-bubble is believed to have formed from the birth of vibrant stars and the subsequent shock waves created by supernova explosions.
These insights are critical to understanding the associated processes for the formation of galaxies and the cycles of stellar birth and death.
the research journey
The team began its pioneering exploration of ultra distant galaxies with ALMA in 2012 and made a discovery in 2016 by detecting waves of oxygen ray in a galaxy located at a record distance. They continued to push the limits and identified the most distant galaxy ever known, detecting radio waves emitted by oxygen at 13.28 billion light-years away in 2018.
In 2019, researchers honed their findings by detecting radio waves emitted by oxygen and dust in another galaxy called MACS0416_Y1located 13.2 billion light years away.
detection of dust at the beginning of the universewhere the reincarnation cycle of stars had not yet been widely repeated, it was a remarkable discovery in our understanding of the cosmos.
One of the most notable findings from these observations is the presence of dark nebulae in the early universe. These clouds of cold dust and gas are dense and hide the light of the stars, for which they also serve as the crucible for being born.
The team’s intricate observations reveal the life cycle within dark nebulae: stars are born, live and diegiving rise to new ones. In their most recent effort, the research team achieved unprecedented high resolution images of MACS0416_Y1.
A colossal cavity at the center of the galaxy
By setting ALMA’s antennas as a zoom target and using an exposure duration of 28 hours, experts were able to discern the origin of radio waves emitted by dust and oxygen, showing how emission nebulae and dark nebulae are closely intertwined, each creating its own space.
This type of dancing is indicative of a process in which new stars are born inside dark nebulae. ionize the surrounding gas.
Furthermore, the images reveal a colossal cavityapproximately 1000 light-years away, at the center of the galaxy, which is possibly a superbubble. Previous studies indicated that MACS0416_Y1 was producing stars yet rhythm incredible, about a hundred times taller than the Milky Way.
This frantic rate of star formation likely led to the creation of this super-bubble through back-to-back supernova explosions.
The team was also able to analyze the movement of the gas within the nebulae, discovering that it is in a turbulent statewith speeds reaching 200,000 kilometers per hour.
“Under such undisciplined conditions, it is suggested that stars can form as massive cumulus“, says Professor Tamura. Furthermore, he adds that these star clusters are characteristic of galaxies in the early universe.
Takuya Hashimoto of the University of Tsukuba praises ALMA’s performance: “It’s equivalent to capturing the extremely faint light emitted by two fireflies located three centimeters apart from each other. the top of Mount Fuji seen from Tokyo, and be able to distinguish between these two fireflies.”
“The importance of this study lies in bringing to light the maximum performance of ALMAthat will allow us to understand the formation of the first galaxies, the life and death of stars and the ecocycle of matter in the universe”, concludes the astronomer.