Astronomers are stunned after James Webb Space Telescope detected tiny dust particles: 'It shouldn't survive'
The James Webb Space Telescope (JWST) has uncovered astronomical dust that should not have existed, as per current assertions. The dust comes from a distant galaxy, Makani (Hawaiian for "wind"), officially known as SDSS J211824.06+001729.4. Findings regarding this have been published in The Astrophysical Journal. Readings from the JWST suggest that dust from this galaxy survived its voyage until the circumgalactic medium (CGM). This finding is remarkable because dust shouldn't survive a temperature above 17,000 degrees Fahrenheit (about 10,000 degrees Celsius), which the voyage provides. But somehow this one did.
Dust from Makani
This dust originated from Makani due to two bursts of star formation, according to Space.com. These bursts took place 7 million years ago and 0.4 billion years ago. The process resulted in strong galactic winds around 326,200 light-years in size. The winds were first detected by astronomers in 2019 and were noted to be pushing out gas and dust towards the CGM, which is the galaxy's massive halo of hot gas. To understand how the dust was behaving in this scenario, researchers used JWST's infrared instruments to focus on the faint light exhibited by polycyclic aromatic hydrocarbons (PAHs). These organic molecules are typically attached to dust grains while they move through the galaxy.
Sylvain Veilleux, an astronomy professor at the University of Maryland, College Park, claims this is the first time astronomical dust has been observed across such a massive distance. "Webb was the key that made it happen," Veilleux shared, according to the press release. The insights provided researchers with a better picture of how galaxy recycles their raw materials, like dust, which are later used to manufacture more stars. The changes in this dust particle also provide hints on how galaxies change over time.
Voyage of the Dust
Researchers claim that this dust traveled for around 100 million years to reach from the galactic center to the CGM. The evidence clearly suggested that the dust survived the journey, something astronomers were not expecting it to. "If dust touches gas at 10,000 degrees, it's going to vaporize it. It shouldn't survive," Veilleux said. Researchers noted that during the long journey, the dust showed hints of disintegration, but it never completely disintegrated. Experts speculate that the dust may have sustained due to cooler lumps of gas surrounding it, from hot temperatures. To conclude this assertion, astronomers want to use JWST to understand the spectrum of the dust particles. The spectrum or 'fingerprint' of the dust particles will reveal their properties, like size, and may expose why it managed to achieve this surprising feat.
Future Studies
Researchers also want to increase the span of their monitoring from 100 million years to several more. They want to take into consideration the dust voyage between two galaxies. "The next question is, 'Can we ever detect dust in the intergalactic medium?'" Veilleux said. "That would be very exciting because it would mean that the full cycle is closed—that dust is not only in the halo of the galaxy, but even beyond that." Such findings could help experts shed light on both the past and future of galaxies.