universeScientists have announced what they believe to be some of the earliest galaxies that formed in astronomers. This intriguing discovery was made byM Aeronautics and Space Administration (NASA)known as the largest space telescope everJames Webb Space Telescope (JWST)Thanks to
“this isHubble Space Telescopeis the first significant sample of a candidate hidden galaxy,” astronomer Yang Haojin told reporters at a meeting of the American Astronomical Society in Seattle on Jan. 9, 2023. speaking at a meeting. Yang, of the University of Missouri, is the lead author of the newly published study.
With greater sensitivity than the Hubble Space Telescope, JWST will be able to see deeper into space, essentially looking further back into the past. Among the 87 galaxies spotted by astronomers using the telescope, some could be dated to about 13.6 billion years ago, just 200 million years after the Big Bang.
It is the galaxy that emitted the light that we see today. But those galaxies of stars, gas, and dust might have changed dramatically if they still exist today.
Scientists have previously studied other distant galaxies dating back to when the universe was young, but Yang and colleagues’ findings could shatter those records by hundreds of millions of years. However, all of them are considered “candidate galaxies” at this time, and their birth dates still need to be confirmed.
Possibility of being a galaxy 13.6 billion years ago
Galaxies can be difficult to date. Astronomers need to measure “redshift,” a measure of how much light a galaxy emits is stretched toward red wavelengths, which allows astronomers to measure how fast galaxies travel through a rapidly expanding universe. We can know when you are moving away from us.
It tells us the distance from the Earth to the galaxy, or more precisely, the distance that a photon emitted from a star in the galaxy travels at the speed of light to reach a near-Earth space telescope such as JWST. give me The light emitted by the stars in the most distant galaxy found here could have been 13.6 billion years ago, which is thought to be very early in the formation of this young galaxy.
These newly estimated distances need to be confirmed using spectra in the future. That means measuring the light emitted by galaxies across the electromagnetic spectrum and pinpointing their unique features.
Still, Yang hopes to accurately measure that many of these galaxies are from the early universe. “I would bet $20 and a beer that there is a 50% chance of that happening,” Yang says.
Yang’s team used JWST’s near-infrared camera (NIRCam) to image these galaxies at six near-infrared wavelengths. A standard technique called “dropout” was used to estimate the distance.
The hydrogen gas that surrounds the galaxy absorbs certain wavelengths of light. So by looking at the wavelengths at which the object can and cannot be seen, we can narrow down how far away the object is likely to be.
Most of the 87 galaxies here look like clumps that can only be detected at the longer (i.e., red-shifted) near-infrared wavelengths that are detectable by NIRCam. This makes it very distant and possibly a very old galaxy.
But some galaxies may be much closer than expected, which means they aren’t that old. For example, some wavelengths may not be detected simply because the light is too weak. But until he can gather more detailed data, Yang won’t know for sure.
High resolution and sensitivity of JWST contributed
Many astronomers have been looking forward to using this new space telescope to study massive galaxies in the early universe containing millions, and sometimes billions, of stars. Each galaxy grows into a unique shape over time. Many of them have a sombrero-like shape, with a bulging inner portion and a thin, disk-like galaxy extending outward.
