Webb turns two with a vivid portrait of interacting galaxies

12 Jul. () –

A duo of interacting galaxies, known as Arp 142, 326 million light years from Earth, commemorates the second scientific anniversary of the NASA/ESA/CSA James Webb Space Telescope.

Their ongoing interaction It was set in motion between 25 and 75 million years ago, when the Penguin (catalogued individually as NGC 2936) and the Egg (NGC 2937) completed their first pass. They will continue to bob and shimmy, completing several additional loops before merging into a single galaxy hundreds of millions of years from now.

The James Webb Space Telescope makes constant observations, including images and very detailed data known as spectra. Its operations have led to a “parade” of discoveries by astronomers around the world. It has never seemed more possible to explore every facet of the Universe, according to the ESA website dedicated to this space telescope.

The telescope’s expertise in capturing infrared light, which is beyond what our own eyes can detect, shows these galaxies, collectively known as Arp 142, caught in a slow cosmic dance. Webb’s observations—combining near- and mid-infrared light from the Near Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), respectively—clearly show that they are united by a blue haze that is a mixture of stars and gas, the result of their mixture.

Before its first approach, the Penguin was shaped like a spiral. Today, its galactic center shines like an eye, its uncoiled arms now forming a beak, a head, a spine and an unfurled tail.

Like all spiral galaxies, the Penguin is still very rich in gas and dust. The “dance” of the galaxies gravitationally pulled on the thinner regions of gas and dust in the Penguin, causing them to collide in waves and form stars. These zones are concentrated in areas in two places: what looks like a fish on its “beak” and the “feathers” on its “tail.”

Surrounding these newer stars is smoke-like material that includes carbon-containing molecules known as polycyclic aromatic hydrocarbons, which Webb uniquely detects. The dust, seen as fainter, deeper orange arcs, It also rushes from its beak to its tail feathers.

In contrast, the Egg’s compact shape remains largely unchanged. As an elliptical galaxy, it is filled with aging stars and has much less gas and dust that can be swept away to form new stars. If both were spiral galaxies, each would end the first “spin” with the formation of new stars and spinning loops, known as tidal tails.

Another reason for the Egg’s undisturbed appearance is that these galaxies have roughly the same mass, so the smaller-looking elliptical was not consumed or distorted by the Penguin.

Penguin and Egg are estimated to be about 100,000 light-years apart, which is pretty close in astronomical terms. For context, the Milky Way and our nearest neighbor, the Andromeda galaxy, are separated by about 2.5 million light-years, about 30 times the distance. They will also interact, but not for about 4 billion years.

At the top right of the image is an edge-on galaxy, cataloged PGC 1237172, which lies 100 million light-years closer to Earth. It is also quite young, packed with new blue stars. In Webb’s image, which shows only the mid-infrared, PGC 1237172 virtually disappears.The mid-infrared light largely captures cooler, older stars and an incredible amount of dust. Because the galaxy’s stellar population is so young, it “disappears” in the mid-infrared light.

Webb’s image is also packed with distant galaxies. Some have spiral and oval shapes, like those found in the “tail feathers” of the Penguin, while others scattered everywhere are shapeless dots.

Although these observations only took a few hours, Webb revealed galaxies far more distant, redder and dustier than previous telescopes — all the more reason to hope that Webb will continue to expand our understanding of everything in the Universe, ESA said.

During its second year of operations, Webb has advanced its scientific goals with new discoveries about other worlds, the life cycle of stars, the early Universe, and galaxies over time. Astronomers have learned about the conditions under which rocky planets can form. and have detected icy ingredients for the worldshave found tellurium created in stellar mergers and have studied the supernova remnants SN 1987A and the Crab Nebula.

By peering into the distant past, Webb has solved the mysteries of how the Universe reionized and the emission of hydrogen from galaxy mergers, and has seen the most distant merging of black holes and galaxies ever observed. Observations with Webb have also confirmed the tension between measurements of the Hubble constant, deepening a different mystery surrounding the expansion rate of the Universe.