The James Webb Telescope is teaching astronomers more about how stars are born

They are common in our solar system and in distant galaxies.

The organic molecules of polycyclic aromatic hydrocarbons (PAHs) contain one or more rings of carbon atoms. Molecules have special properties that allow them to be used to track regions where stars are forming.

Research on data from the James Webb Telescope (WEB) may now influence how astronomers use these particles.

Particles emit infrared light

The first polycyclic aromatic hydrocarbon molecules were identified in space during 80s It has since been found in everything from dust clouds in distant galaxies to the atmosphere of Saturn’s largest moon, Titan.

When a PAH molecule is exposed to ultraviolet or visible light, for example from a young star, it can be excited – its energy level changes. When the molecule then returns to its original state, it emits infrared light at specific wavelengths.

In this way, astronomers can use clusters of polycyclic aromatic hydrocarbon molecules to track the regions where stars are forming.

in study Which was recently published in the magazine Astronomy and astrophysics A British research team examined data from three galaxies collected by the Web Merry instrument. The selected galaxies are NGC 6552, NGC 7319 and NGC 7469 and are located 370, 311 and 200 million light-years away from us, respectively.

The aim of the study was to compare the abundance of PAH molecules in two regions where star formation can occur. At the center of active galaxies – near what are known as active galactic nuclei – and in the somewhat calmer environment of the arms of spiral galaxies.

The results contradict previous theories

Previously, scientists believed that radiation around active galactic nuclei, supermassive black holes, would break and destroy all PAH molecules. The study results show that this is not the case, although black holes appear to affect the particles that survive.

There are different types of PAH molecules – larger, electrically neutral, smaller and electrically charged.

The study showed that the quieter regions in the arms of spiral galaxies are dominated by the latter type, while the particles that make them around black holes are larger and electrically neutral.

– It is great to observe PAH molecules in the core region of the galaxy and the next step is to analyze a larger group of active galaxies with different properties. This will enable us to better understand how PAH molecules survive and what their specific properties are in galactic cores. This kind of knowledge is key to using particles as a tool for quantifying how much stars form in galaxies, and thus understanding how galaxies evolve over time, said Ismael García Burnett, PhD, in the Oxford Department of Physics, in press release.

One possible theory as to why larger PAH molecules remain near black holes is that they are shielded by large amounts of gas. According to the study, the results bring new limitations on how organic molecules can be used to determine the regions where stars are born in the future.

New image of the pillar of creation

There have also been other findings from Webb regarding how and where stars form.

recently released Pictures From the Eagle Nebula you can see three huge pillars of dust and gas called the Pillars of Creation. The pillars have previously been imaged by other telescopes, including the Hubble telescope, Spitzer Space Telescope And the Herschel Space Observatory.

Webb is much more powerful than its predecessors and the image of the nebula shows new details. For example, red regions are clearly visible at the top of the columns – this is where new stars are formed.

When the star forms and grows sufficiently, large amounts of dust and dust are pushed away from the area around the star. The material being pushed away is then heated, emitting infrared light that Webb can see.

The new data will be used to better understand how stars form in the nebula.