It is known that deep in the Earth, high pressures and temperatures lead to the formation of diamonds from carbon. It should be the same with the carbon dust produced by stars at the end of their lives in the red giant stage as well as with supernova explosions. In fact, for decades, nanodiamonds have been discovered in presolar grains, older than the solar system that can be found in the oldest carbonaceous meteorites.
They are bodies containing a few thousand carbon atoms that form a distinct crystalline structure and aggregate to a size of a few nanometers, a billionth of a meter in diameter. It can be obtained as the milky residue of a portion of a carbonaceous meteorite dissolved in acid.
Today, as described in an article published in natureIt is believed that the infrared signature of these nanodiamonds may have been observed in galaxies as detected by the James Webb Space Telescope about a billion years after the Big Bang at most.
Galaxies that grew faster than theory predicts?
Joris Wittstock of the University of Cambridge, one of the principal astrophysicists behind the discovery, explains: Carbon-rich dust grains may be particularly good at absorbing ultraviolet light with a wavelength of about 217.5 nanometers, which we first observed directly in the spectra of very old galaxies. Let us recall in passing that James Webb (JWST) sees in the infrared spectra that its light is shifted toward the red by the expansion of the universe, for example the lines present in the ultraviolet at the origin.
In the same ESA press release, fellow team member Rinsky Smit, a team member at Liverpool John Moores University, UK, added: This finding indicates that infant galaxies in the early Universe grew much faster than we expected. Webb shows us a complication in the early birthplaces of stars (and planets) that models have yet to explain “.
Again, the Hubble successor gives us indications that galaxies have evolved faster than we expected for a few decades, which may indicate that the standard cosmological model needs to be revised, for example by substituting the presence of dark matter for a modification of the laws of gravity under Mond theory, although it is still too early to conclude that this James model is not in fact able to predict the observations of the Web.
By the way, though buzz Modern and highly exaggerated to the ire of the cosmologist community, we have no serious reason to believe that the observable universe is more than 13.8 billion years old and in particular 26.7 billion years old, as suggested by physicist Rajendra Gupta by multiplying rotation. In particular, we’ve known for decades that the “tired” light theory—proposed to explain the spectral redshift without involving the visible universe—leads to at least three predictions that are refuted by observations at around 10 sigma, to use physicists’ terminology (Learn what cosmologist Ned Wright has been saying for a long time). A refuted score at 5 sigma already means that there is only a 1 in a million chance that the rebuttal is wrong, which is a much smaller chance even with 10 sigma.
This gives an idea of the credible, if logically possible, small acrobatics that would have to be multiplied to get an age of 26.7 billion years. In particular, it is necessary to assume that some fundamental constants of physics vary over time when there are already very strong constraints on these possible differences, and also to take into account the chronometer-dating of star clusters and the abundance of certain nuclei in the Milky Way not all of which correspond in a first approximation to a universe already older than 13.8 billion years.
Nanodiamonds or PAHs?
But let’s go back to the discovery of nanodiamonds. In fact, the signature detected by James-Webb can be well explained in the case of observed galaxies such as they were only a few billion years ago by the abundant presence of carbon molecules, which are called PAH cousins to benzene molecules ( Polycyclic aromatic hydrocarbons or PAH, in English). But in galaxies about 600 million years old after the Big Bang, such as those observed as part of JWST Advanced Deep Extragalactic Survey (Jades), this hypothesis is not credible according to astrochemists who thus conclude that nanodiamonds are very likely to be observed.
if so,” This discovery was made possible by the unprecedented improvement in the sensitivity of Webb’s near infrared spectroscopy, in particular the near infrared spectrometer (NIRSpec). The increase in sensitivity provided by Webb is equivalent, in visual terms, to the immediate upgrade of the 37 mm Galileo telescope by A very large telescope 8 meters ESO Roberto Maiolino, a member of the University of Cambridge WUniversity College London Behind the discovery of nanodiamonds.
” We plan to work more with theorists who are modeling the production and growth of dust in galaxies. This will shed light on the origin of dust and heavy elements in the early universe. University of Arizona team member Erin Shifaei added, Astrobiology Center (Taxi).
Nanodiamonds and meteorites. For a more or less accurate French translation, click on the white rectangle at the bottom right. The English translation should then appear. Then click the nut to the right of the rectangle, then click Subtitles and finally Subtitle Automatically. Choose “French”. © thebrainscoop
