Molecular thermometer for distant universe

Astronomers using the giant telescope the Very Large Telescope (VLT) of Eso have for the first time discovered in carbon monoxide molecular ultraviolet radiation in a galaxy nearly 11 billion light-years away, a feat but 25 years have not been achieved. This discovery allows them to best measure the cosmic temperature at such a far point.

Astronomers target the UVES spectrometer on ESO's VLT glass into a galaxy that hides more than 8 hours, the light of this galaxy loses 11 billion years to us, a time of about 80% of the age of the universe.

The only thing this galaxy can see is through its trace of interstellar gas left on the spectrum of a quasar even further.

Thanks to the strength of the VLT and the carefully selected target - the target is selected among 10,000 quasars - the team was able to detect the presence of normal molecular hydrogen and heavy deuteri (H ₂ , HD) and CO molecules in the interstellar environment of this distant galaxy.

The VLT glasses observe (D) characteristics related to 3 systems, at 3 different distances (A, B and C), and so their light changes with different intensity. Quasar, acting as a beacon, is the brightest object on the left of the image (Photo: ESO)
The interstellar gas is where the stars form and, in a sense, is an important component of galaxies. Moreover, because the formation and state of the molecules is very sensitive to the physical conditions of the gas, which in turn depends on the extent to which the stars form and their influence, so the study Saving chemical details of interstellar environments is an important tool to understand how galaxies form.

Based on their observations, astronomers have shown that the dominant physical condition in interstellar gas in this distant galaxy is similar to what is seen in our galaxy. .

But most importantly, the team was able to measure the unprecedented accuracy of the cosmic background radiation in the distant universe.

If the cylinder is formed in an explosion, as most astrophysicists deduce, the heat of the original fireball must be hotter in the past. And this is what is discovered by new measurements.

'The current measured temperature is 2725 degrees K, the temperature 11 billion years ago must be about 9.3 degrees K. The set of observations of the VLT glass allows us to deduce a temperature of 19 , 5 degrees K, plus or minus 0.7 degrees K, fits perfectly with the theory, 'said team member Patrick Petitjean.