Astronomers observe how galaxies formed in early days of universe
Consisting of 66 12-meter (39 ft.), and 7-meter (23 ft.) diameter radio telescopes observing at millimeter and submillimeter wavelengths, ALMA is expected to provide insight on star birth during the early universe and detailed imaging of local star and planet formation.
Due to the sheer distance between the telescope and its subject, the galaxies ALMA is watching form were actually born less than a billion years after the Big Bang, during a period known as the epoch of reionisation.
Many researchers have focused on extremely bright objects in the distant past that would be easier to see, such as galaxies with extremely high rates of star formation. According to astronomer and the study’s co-author Andrea Ferrara from Italy’s Scuola Normale Superiore, “This is the most distant detection ever of this kind of emission from a “normal” galaxy, seen less than one billion years after the Big Bang”.
“For the first time, we are seeing early galaxies not merely as tiny blobs, but as objects with internal structure”, he added. These were the galaxies that re-ionized the universe and set the platform for most of the galaxies seen today.
In this search, ALMA obtained a thin but clear signal of glowing carbon from a galaxy named BDF3299 that could be a typical example of galaxies responsible for reionization of the universe. Researchers think that carbon’s glow is obscured by the supernova blasts and chaos of galactic formation there, but the cold store of carbon nearby still shines as the galaxy draws from it. As these clouds started to coalesce into stars through a process called reionization, the clouds dissipated and became hard to see. The gas most likely surfaces from the outskirts of BDF 3299 being pushed towards the margins by the newly formed stars at the center of the galaxy. This is going to be their first opportunity to test the predictions & hypotheses on any real data which makes for a very exciting moment and also opens up many new questions. According to the team at the ESO, the study has been led by Roberto Maiolinio of the University of Cambridge.
In Big Bang cosmology, reionization refers to the process of reionizing matter, which is the second of two major phases of the transition of gas, with the first begin the change of hydrogen in the universe, called recombination.
ALMA spots the glow of accreting gas in the early universe. Ultimately, we want to do even more, but there’s a minor problem with that… Although this is one of the deepest ALMA observations so far it is still far from achieving its ultimate capabilities.