A team of astronomers has observed a galaxy from early days of the universe undergoing a tremendous burst of star formation. The galaxy, seen by astronomers as it was just over a billion years after the Big Bang, is emitting extremely bright infrared emission — a smoking gun of star birth.
According to a study detailing the observations, published in the latest edition of the Astrophysical Journal, the galaxy — named SPT 0346-52 — is forming stars at a staggering rate of 4,500 times the mass of the sun every year. This is in contrast to galaxies like the Milky Way, which form stars at a more sedate rate of roughly one solar mass every year.
“Astronomers call galaxies with lots of star formation ‘starburst’ galaxies,” study co-author Anthony Gonzalez from the University of Florida, said in a statement released Thursday. “That term doesn't seem to do this galaxy justice, so we are calling it a ‘hyper-starburst’ galaxy.”
In order to confirm that the bright infrared light being emitted by the galaxy is in fact the result of star birth — and not of gas and dust falling into the supermassive black hole at its core — the researchers also looked for signs of X-rays and radio waves in the emission spectrum.
Observations conducted using NASA’s Chandra X-Ray Observatory failed to detect any such emissions. This means that the infrared emission is coming mostly from the galaxy’s reservoir of cold gas being converted into stars with an “unusually” high efficiency.
“We now know that this galaxy doesn't have a gorging black hole, but instead is shining brightly with the light from newborn stars,” lead researcher Jingzhe Ma, a graduate student at the University of Florida, said in the statement.
Scientists believe that studying SPT 0346-52 and other ancient galaxies like it can provide vital clues to the formation and evolution of galaxies and the stars in the cosmos’ early days. In addition, it can help us understand the correlation between the growth of massive galaxies and the evolution of supermassive black holes at their center.
“For decades, astronomers have known that supermassive black holes and the stars in their host galaxies grow together,” co-author Joaquin Vieira from the University of Illinois at Urbana-Champaign said in the statement. “Exactly why they do this is still a mystery. ... We would really like to study this galaxy in greater detail and understand what triggered the star formation and how that affects the growth of the black hole.”