Until recently, astronomers were unable to observe the first stars and galaxies to form in the universe. This occurred during the period known as the “Cosmic Dark Ages”, which took place between 380,000 and 1 billion years after the Big Bang. with new generation tools such as James Webb Space Telescope (JWST), advanced methods and software, and upgrades to existing observatories, astronomers are finally lifting the veil over this era and seeing how the universe as we know it came to be.

This includes new observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which captures images of stellar nurseries in a galaxy about 13.2 billion light-years away in the constellation Eridanus. The redshift of this galaxy is greater than 8.3, which corresponds to when the universe was less than 1 billion years old. The images show star forming regions and possible star death within the nebula (MACS0416_Y1) in this galaxy. This is an important milestone for astronomy as it is the furthest distance in our universe such structures have been observed.

The group was led by Yoichi Tamura, a graduate student in astronomy from Nagoya University. Researchers from Japan’s National Astronomical Observatory (NaOJ), Vasseda Scientific and Technical Research Institute, Tomonaga Center for the History of the Universe (Thouou), Space Dawn (Dawn) Center, DTU-SPACE, the Institute for Extraordinary Physics and Social Co-creation Initiative (FSSI), the Statistical Machine Education Research Center, and several universities participated. A paper was published recently describing its findings. Astrophysical Journal

In this cosmic dark age, clouds of neutral hydrogen permeated the universe, and the only source of light was residual radiation from the Big Bang – what can be seen today as the cosmic microwave background (CMB) – and radiation created by the reionization of hydrogen. This turned out to be the oldest population of stars (Population III), which is very bright and hot by modern standards and emits an enormous amount of ionizing energy. This led to the era of reionization, when the universe became transparent and its structures became visible in modern telescopes.

In this case, the team previously detected radio waves emitted by oxygen and dust, two components of the interstellar medium (ISM) and star-forming nebulae, which absorb radiation from the birth of new stars. However, his initial observations were not sharp enough to make detailed observations that would show the distribution of dust and gas and the structure of the nebula. To this end, the team used ALMA to observe MACS0416_Y1 for 28 hours, showing the intricate intertwining of dust signal and oxygen emission regions.

The images released by the team (shown above) show only ALMA dust emission (right), while the left image shows certain emission data combined with starlight from the Hubble Space Telescope. Dust is marked in red, oxygen in green, and starlight in blue. A vertically elongated void that may be a superbubble is visible in the center of the dust eruption image at right and appears as a longitudinal black area.

Takuya Hashimoto, an astronomer at the University of Tsukuba and co-author of the paper, explained the difficulty in obtaining these observations in a recent NOAJ press release: “This corresponds to the capture of extremely weak light emitted by two fireflies spaced 3 centimeters apart. Being able to distinguish between and separately from the top of Mount Fuji as seen from Tokyo.” Source