The discovery of galaxies in the early universe—that is, observed only hundreds of millions of years after the big Bang— provides astronomers with new insights into the early history of the universe. In particular, by studying their colors, astronomers can reconstruct their main physical properties, such as their stellar mass, their age, or the presence of supermassive black holes in their nuclei.
A group of scientists, in which the Department of Astronomy and Astrophysics of the University of Valencia (UV) participates, has discovered a population of six galaxies observed at one time between 500 and 800 million years after the big Bang, and characterized by an intrinsic color redder than usual in cosmic formations of the same time.
“The most fascinating thing is that, even if only a fraction of these new objects were to be confirmed, this would already imply masses between 10 and 100 times greater than expected,” he says. Mauro StefanonUV researcher and one of the signatories of the article published this Wednesday in Nature.
The combination of all these factors—number of galaxies, mass, and stellar age—proposes to the research team that star formation could have been a much more efficient process from what has been considered up to now.
“The galaxies observed at these times have generally shown blue colours, indicative of an intense formation of new stars”, comments the scientist. Instead, and unexpectedly, galaxies now identified exhibit redder colorswhich makes them candidates to be part of the list of ancient galaxies in the early universe”, he adds.
The James Webb Space Telescope, key in the discovery of galaxies
For the purposes of the human eye and from Earth, the population of galaxies identified in this work occupies a small region of the sky. equivalent to one twentieth of the Moon’s surface. Approaching the cosmos and achieving the results now obtained by the international team led by astrophysicist Ivo Labbé (Centre for Astrophysics and Supercomputing, Australia) is something for which science has to thank the James Webb Space Telescope (JWST).
This observatory, the result of collaboration between the space agencies of the United States (NASA), Europe (ESA) and Canada (CSA), is providing the scientific community with its first insight into star formation, gas and dust in galaxies. through 98% of the history of the universe. With unprecedented resolution and sensitivity at infrared wavelengths, essential for detecting the most distant galaxies.
“The James Webb telescope allows you to capture images with up to 20 times higher resolution and much more sensitive data than those obtained to date with the Hubble and Spitzer space telescopes. Findings like this confirm the effectiveness of the space observatory and the effectiveness of studies that use its multiple filters to identify and characterize the first galaxies”, says the UV researcher.
This article was first published on SYNC