The stunning deep-infrared image of the universe by the James Webb Space Telescope has revealed 42 new galactic lenses, revealing an unprecedented depth of lens shape and finally helping us see the first galaxies.
disclosure of James Webb Space Telescope Deep shot of US President Joe Biden in a special presentation event at the White House Who was detained on July 11 was a closely guarded secret. Teams of astronomers rushed to be the first to analyze it, with three new research papers posted to the community’s pre-print server within a week of the image’s release.
“We were a bit sad, to be honest!” Brenda Fry, an astronomer at the University of Arizona Steward Observatory and co-author of one of the papers, told Space.com. “Usually we have a warning a year or two in advance, but no one has seen it [this release] Come right now.”
Gallery: The first images from the James Webb Space Telescope
Related: How does the James Webb Space Telescope work?
That universe The SMACS J0723.3-7327 cluster, abbreviated as SMACS J0723, is one of a group of galaxy clusters imaged by Webb for several gravitational lensing surveys. Additionally, Frye said there has been nothing unusual about SMACS J0723 so far.
Beautifully chosen [to be one of the first images] Because it was a relatively unknown goal.”
gravitational lens A phenomenon where the gravity of a very massive object causes space to bend into a shape similar to an optical lens, distorting the light from what is behind the lens and amplifying it in brightness. Galactic clusters are particularly effective lenses because they contain an enormous amount of mass (in the case of SMACS J0723, about 100 trillion times the mass of the Sun) in a relatively compact volume about 3 to 5 million light-years in diameter.
Previous polls conducted by Hubble Space Telescope and retired Herschel Space Observatory They found a pair of lenticular images of background galaxies in their SMACS J0723 observation. But Webb takes research to a whole new level.
The Frye team, led by graduate student Massimo Pascal of the University of California, Berkeley, discovered 42 new lens images in the background of the new deep-field image. Gravitational lensing can create multiple images of the same galaxy, so these 42 images represent 19 separate galaxies. Another team led by Gabriel Caminha of the Max Planck Institute for Astrophysics in Germany counted 27 images with a new lens.
Regardless of the end result, these lenticular images allow scientists to refine the map of how matter is visible and visible dark – Distributed in the SMACS J0723 series that designs the shape of the lens. One of the new papers, from a team led by Guillaume Mahler of Durham University, concludes that most of the mass is concentrated in the cluster’s brightest and most massive galaxy.
“Our models not only describe mass, but we can also use them to describe the magnification of these lenticular images,” Pascal told Space.com.
Currently, the most distant confirmed galaxy is a distant object known as GN-z11which has a redshift of 11.09, which means we see it as it was 13.4 billion years ago, i.e. only 400 million years after the big explosion. (“Redshift” refers to the wavelength of light that occurs when the universe is stretched between a distant object and the viewer. The higher the redshift factor, the farther away the light source is.)
The most distant candidate is HD1, which was discovered at a redshift of 13, appears to us as it did just 300 million years after the Big Bang. and recently, Web Early results It identified another candidate galaxy at redshift 13, called GLASS-z11. However, astronomers have not confirmed the redshift of HD1 or GLASS-z11.
Webb is expected to break both redshift records, although it has not yet been determined which of the lens systems observed in SMACS J0723 is beyond Gn-z11 or HD1. Pascal and Frey are interested in mapping a phenomenon called the “critical curve” because a gravitational lens applies the greatest magnifying power along these curves and where astronomers have the best chance of seeing The first galaxies.
“The typical magnification in the lensing cluster is almost 10 times, which is not enough to see the first galaxies,” Frey said. “But if we look close to the critical curve, things there are magnified hundreds or even thousands of times.”
Think of a critical curve as the contour lines on a topographic map of a surface a country. The more these contour lines are grouped together, the higher a particular spot on the surface will rise. Likewise, the critical curve is where the contour lines of gravitational potentials converge, and the more of them there are, the greater the strength of this potential and the magnification that comes with it. The position and shape of the images with a lens can give an indication of where the critical curve is located.
“Ultimately, we’ll look right along the critical curve where the magnification is higher, and that’s where we’ll find the highest redshift galaxies,” Frey said.
It is for this reason that Webb’s first three new papers on the deep field focus on modeling the amount and distribution of matter in the front mass and thus the shape of the lens and the location of the critical curve.
However, modeling can also tell us something about the history of the galactic cluster.
“We felt that overall distribution was a little longer than expected,” Pascal said. “Perhaps that says something about History of cluster fusionand we can extrapolate that and learn something about the formation of the block as a whole, which happens in a very chaotic environment where gravity All these galaxies attract each other.”
The immediate next step for Pascal, Frey’s team and the two other authors of the papers is to follow the peer-review process to see these findings published in scientific journals. In addition, data from NIRISS (Near Infrared Imager and Slit Spectrometer) is waiting to be analyzed and should help scientists determine the spectral redshift of lenticular galaxies and see how far away they are. (The deep-field image was captured by NIRCam, the near-infrared camera.)
“Before Webb filmed him, SMACS J0723 was not the star of the show,” said Pascal. “Now suddenly it’s paper after paper that’s really saying how powerful the Webb Web is, revealing things we couldn’t see before.”
The first version of Pascal and free paper can be found here. The other two cards are available here And here.
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