In the central region of the Milky Way, a dense, cold, mysterious molecular cloud should also contain nurseries for star formation according to the standard theory of star formation. It has been known for years that this is not the case, and a lively debate has developed about why. The James Webb Telescope was mobilized to try to solve this mystery.
The theory has been around for about a century, was later refined, and we are indebted to it physicalphysical, astronomerastronomer And MathematicianMathematician British James Jeans (1877-1946), which shows that A cloudsclouds A substance in the form of a gas that has a certain density and temperature must collapse due to gravity if its mass is greater than the calculated value doordoor Today’s name A block of jeans. It allows us to know when such a cloud is in the conditions necessary to form a stellar nursery.
to’CollapsesCollapses The primordial cloud can cause density and temperature to evolve locally so that the cloud in turn splits into denser regions giving rise to stars, sometimes in the form of double stars, fleeting or not – we estimate that our solar planet may have been born with a twin sibling who later moved on.
However, it seems strange that Jean’s theory fails when we look at the central molecular zone (CMZ), a gas complex 1,000 to 2,000 light-years in diameter around the Earth. Galactic centerGalactic center. They are known to contain some of the densest and most massive gas clouds known in the Milky Way, but surprisingly many of these clouds show little evidence of large-scale star formation activity.
This is particularly surprising in the case of a turbulent gas cloud, which is called a “brick.” Brick In English and more intelligently under the name G0.253+0.016. the AstrophysicistsAstrophysicists We have discussed for years the reason for this lack of new stars, and, of course, one might think that the extraordinary capabilities of new stars Space telescopeSpace telescope James Webb (JWSTJWST) literature can help you see more clearly, as particulate and dusty clouds are much less opaque inInfraredInfrared Only in visual. However, the James Webb Space Telescope observes in the infrared range.
Carbon monoxide ice, key to star and planet formation?
The team is led by an astronomer Adam Ginsburgfrom the University of Florida, understood this very well and today published an article about this mystery using the James Webb Space Telescope in Astrophysical Journalthe article which can be found in open access at arXiv.
Under the gaze of the James Webb Space Telescope, the bricks were found to consist of a surprisingly large amount of… Carbon MonoxideCarbon Monoxide (CO) Frozen. In reality, we didn’t really know what that amount should be, and the usual theories predicted a much smaller amount. This discovery has profound implications for our understanding of star formation processes. Theorists will have to revise their versions.
In fact, the presence of a large amount of carbon dioxide ice usually indicates the presence of a very cold cloud with significant star formation. The fact that this is not the case means that the cloud is warmer (than it naively seems) than similar clouds. but why ?
What is certain is that, as Ginsburg explained in a press release, “ With the James Webb Space Telescope, we are opening up new ways to measure MoleculesMolecules phase solidsolid (ice), while we previously limited ourselves to studying gas. This new view gives us a more complete look at where molecules are located and how they are transported “.
What we can also say is that we may have to rethink what happened in the protoplanetary disk at the origin of the solar system’s planets. Solar systemSolar systemIce giants in particular because we have every reason to believe they formed from dust covered by a matrix of ice, necessarily water.
So the James Webb Space Telescope has proven itself capable of tackling these kinds of questions, and in the near future with it, Ginsberg aims to conduct a more in-depth study of celestial ice: We do not know, for example, the relative amounts of carbon dioxide, water, and carbon monoxide2 and complex molecules. Using spectroscopy, we can measure them and get an idea of how they occur chemistrychemistry It advances over time in these clouds “.
