Origins for the veil of burning gas in the Milky Way disk

Nov. 22 () –

Scientists may have finally discovered the possible mysterious sources that have pumped heat and kept the burning gas alive recently detected around the galaxy’s disk.

There is more gas than stars in our galaxy. The predominant and massive reservoir of gas is the main source of star formation in our galaxy. The abundant availability of gas helped maintain this process to this day. However, due to its faint nature, astronomers have found it extremely difficult to see, much less measure the volume of this gaseous matter.

But a few decades ago, studies established the presence of gaseous matter around our galaxy, the Milky Way. The galaxy was discovered to be surrounded by a large sphere of gas that had a temperature of a few million degrees Kelvin. This sphere of gas extended up to 700,000 light years. Such high temperatures, the researchers said, could be associated with the gravity of the Milky Way, since the atoms would have to spin constantly to save themselves from falling prey to the galaxy’s strong gravity.

But what most intrigued the scientific community in recent years was the discovery of gaseous matter that was even hotter than previously known. This latest gaseous matter discovered was estimated to be about ten million degrees Kelvin. Faint X-ray emissions were found in all directions of the Milky Way that had a strong signature of a superhot gas. At the same time, this gas also appeared in the spectra of at least three distant quasars, as an absorbent medium.

A much-studied area of ​​research emerged, and since then astronomers have been trying to find clues and links to the sources that pumped out heat and kept the fiery hot gas alive.

Scientists at the Raman Research Institute (RRI), an autonomous institute funded by the Department of Science and Technology (DST), Government of India, along with their collaborators at IIT-Palakkad and Ohio State University, have detailed the mysterious source through its model proposed in two related studies.

They have confirmed that the gas responsible for emitting and absorbing the signals detected by astronomers is not the same, Instead, the hot gas emitting X-rays is caused by an inflated region around the Milky Way’s stellar disk.. Since there is continuous star formation in several regions throughout the Milky Way disk, massive stars in these regions explode as supernovae and heat the gas around the disk to high temperatures.

“Therefore, the explosions continue to heat the gas floating around the Milky Way disk and enrich the gaseous matter with elements synthesized within massive stars,” he said. in a statement Mukesh Singh Bisht, PhD student at RRI.

As this turbulent gas is entrained from the disk and swirls violently, it either escapes into the surrounding medium or cools and falls back onto the disk.

Although there are thousands of runaway stars that are constantly ejected from the Milky Way disk, when some of them that can float above the stellar disk explode as supernovae, They potentially create a cloud of burning, enriched gas around them.

“If aligned with the direction of distant light sources (quasars), the atoms of this hot gas would absorb and produce shadow signals, which would explain the absorption of the hot gas. At the same time, a veil of burning hot gas continues to envelop the Milky Way disk, as a result of star formation activities in the Milky Way stellar disk, which explains the hot gas seen in the X-ray emission,” Bisht said. The study was published in Astrophysical Journal.

The weak X-ray signals thus produced could be studied further to obtain more clues. The group plans to test the models at other frequencies.