It’s 7 billion years ago, and the universe’s heyday of star formation is starting to slow. What might our Milky Way galaxy have looked like at the moment? Astronomers using NASA’s James Webb Space Telescope have found clues in the shape of a cosmic query mark, the results of a rare alignment across light-years of space.
“We all know of only three or 4 occurrences of comparable gravitational lens configurations within the observable universe, which makes this find exciting, because it demonstrates the facility of Webb and suggests possibly now we’ll find more of those,” said astronomer Guillaume Desprez of Saint Mary’s University in Halifax, Nova Scotia, a member of the team presenting the Webb results.
While this region has been observed previously with NASA’s Hubble Space Telescope, the dusty red galaxy that forms the intriguing question-mark shape only got here into view with Webb. It is a results of the wavelengths of sunshine that Hubble detects getting trapped in cosmic dust, while longer wavelengths of infrared light are capable of go through and be detected by Webb’s instruments.
Astronomers used each telescopes to watch the galaxy cluster MACS-J0417.5-1154, which acts like a magnifying glass since the cluster is so massive it warps the material of space-time. This permits astronomers to see enhanced detail in far more distant galaxies behind the cluster. Nevertheless, the identical gravitational effects that magnify the galaxies also cause distortion, leading to galaxies that appear smeared across the sky in arcs and even appear multiple times. These optical illusions in space are called gravitational lensing.
The red galaxy revealed by Webb, together with a spiral galaxy it’s interacting with that was previously detected by Hubble, are being magnified and distorted in an unusual way, which requires a specific, rare alignment between the distant galaxies, the lens, and the observer — something astronomers call a hyperbolic umbilic gravitational lens. This accounts for the five images of the galaxy pair seen in Webb’s image, 4 of which trace the highest of the query mark. The dot of the query mark is an unrelated galaxy that happens to be in the fitting place and space-time, from our perspective.
Along with producing a case study of the Webb NIRISS (Near-Infrared Imager and Slitless Spectrograph) instrument’s ability to detect star formation locations inside a galaxy billions of light-years away, the research team also couldn’t resist highlighting the query mark shape. “That is just cool looking. Amazing images like this are why I got into astronomy once I was young,” said astronomer Marcin Sawicki of Saint Mary’s University, certainly one of the lead researchers on the team.
“Knowing when, where, and the way star formation occurs inside galaxies is crucial to understanding how galaxies have evolved over the history of the universe,” said astronomer Vicente Estrada-Carpenter of Saint Mary’s University, who used each Hubble’s ultraviolet and Webb’s infrared data to indicate where latest stars are forming within the galaxies. The outcomes show that star formation is widespread in each. The spectral data also confirmed that the newfound dusty galaxy is situated at the identical distance because the face-on spiral galaxy, they usually are likely starting to interact.
“Each galaxies within the Query Mark Pair show lively star formation in several compact regions, likely a results of gas from the 2 galaxies colliding,” said Estrada-Carpenter. “Nevertheless, neither galaxy’s shape appears too disrupted, so we’re probably seeing the start of their interaction with one another.”
“These galaxies, seen billions of years ago when star formation was at its peak, are just like the mass that the Milky Way galaxy would have been at the moment. Webb is allowing us to review what the teenage years of our own galaxy would have been like,” said Sawicki.
The Webb images and spectra on this research got here from the Canadian NIRISS Unbiased Cluster Survey (CANUCS). The research paper is published within the Monthly Notices of the Royal Astronomical Society.
