Science

ALMA finds most-distant oxygen in the universe

ALMA finds most-distant oxygen in the universe

The new details revealed that light from a galaxy dubbed MACS1149-JD1 was 13.28 billion lightyears old, an worldwide team reported in the scientific journal Nature.

The oxygen in MACS1149-JD1 was the most distant ever detected. The massive newborn stars in the second burst ionized the oxygen between the stars; it is those emissions that have been detected with ALMA.

The results demonstrate the usefulness of ALMA as a tool for measuring the red shift of distant galaxies, Rychard Bouwens, an astrophysicist at Leiden University, said in another article in Nature. The researchers report in Nature today that they then observed the galaxy in optical frequencies using the Hubble and Spitzer space telescopes to understand its star formation, concluding that it must have begun 300 million years earlier. This period, commonly referred to as "cosmic dawn, ' is of particular interest because it marked the transition from a hot, dense, and almost homogeneous universe to the universe we are more familiar with today - one filled with stars, planets, nebulae, and people".

The team determined that, if the oxygen signature was from 500 million years after the Big Bang, then the first stars in that galaxy would have been born about 250 million years post-Big Bang. When that light was produced in MACS1149-JD1 it was in the infrared, but during its billions of years journeying to Earth, the expansion of the universe stretched it out to the microwave frequencies that ALMA is sensitive to.

Its faint light has taken so long to reach Earth that its journey began just 500 million years after the Big Bang - the cataclysmic event that brought the cosmos into being.

The universe's first stars may have formed a mere 250 million years after the big bang-hundreds of millions of years earlier than thought, according to a new study.

The real breakthrough was the detection of oxygen in the galaxy, which is observable in the Leo constellation, though not with the naked eye.




"With these observations, we are pushing back the limit of the observable universe and, therefore, we are coming closer to the cosmic dawn".

Oxygen was not created in the Big Bang explosion that gave birth to the universe.

The "redshift" of the galaxy, a measurement that establishes the age and distance of a space object, was 9.1096 units, the biggest value obtained so far from the study of spectral lines, as revealed by the report for this study.

The researchers confirmed the distance of the galaxy with observations from ground-based telescopes in Chile and reconstructed the earlier history of MACS1149-JD1 using infrared data from orbiting telescopes.

"Determining when cosmic dawn occurred is akin to the holy grail of cosmology and galaxy formation", said Richard Ellis, co-author of the paper.

'There is renewed optimism we are getting closer and closer to witnessing directly the birth of starlight. "Since we are all made of a processed stellar material, this is really finding our own origins".

"With this discovery we managed to reach the earliest phase of cosmic star formation history", Dr. Hashimoto said.