Arp 220 is one of the brightest infrared galaxies in the nearby universe, with intense star formation fueled by a collision that began 700 million years ago.<\/p>\n
From a distance, Arp 220 looks like a single galaxy with a brilliant center and enormous clouds of glowing material spreading into space.\u00a0<\/p>\n
But the James Webb Space Telescope<\/a> has revealed something far more complicated.<\/p>\n The object is actually two spiral galaxies in the process of merging, creating one of the brightest infrared galaxies in the nearby universe.<\/p>\n Located roughly 250 million light-years from Earth, Arp 220 offers astronomers a remarkable opportunity to study what happens when galaxies collide, gas clouds compress, and new stars begin forming at extraordinary rates.<\/p>\n A collision 700 million years in the making<\/p>\n The story of Arp 220 began about 700 million years ago, when two spiral galaxies started colliding.<\/p>\n Their enormous gravitational forces pulled at each other\u2019s stars, gas, and dust, gradually transforming both galaxies.<\/p>\n Unlike a collision between solid objects, a galactic merger<\/a> unfolds over hundreds of millions of years.\u00a0<\/p>\n Individual stars are so widely separated that direct collisions between them are extremely unlikely.<\/p>\n Instead, gravity reshapes the galaxies, changing the paths of stars and drawing enormous quantities of gas toward their centers.<\/p>\n In Arp 220, that process triggered an intense period of star formation. The merger has become a natural laboratory for understanding how galaxies grow and change.<\/p>\n Although the two galaxies appear to form a single object in Webb\u2019s image, their original cores remain distinguishable.<\/p>\n Earlier observations<\/a> by NASA\u2019s Hubble Space Telescope revealed that these centers are separated by approximately 1,200 light-years. Each contains a rotating ring where stars are forming.<\/p>\n A galaxy brighter than a trillion suns<\/p>\n Arp 220 belongs to a rare category known as ultraluminous infrared galaxies. These objects release enormous amounts of energy, much of it at infrared wavelengths.<\/p>\n According to NASA<\/a>, Arp 220 shines with the luminosity of more than one trillion suns. By comparison, the Milky Way has a total luminosity of roughly 10 billion suns.<\/p>\n Much of Arp 220\u2019s extraordinary infrared brightness comes from dust absorbing energy produced by intense activity within the merging galaxies and radiating that energy at longer wavelengths.<\/p>\n The region surrounding the galactic centers is especially remarkable.<\/p>\n Approximately 200 massive star clusters occupy a dusty area measuring just 5,000 light-years across. That is only about five percent of the Milky Way\u2019s diameter.<\/p>\n Yet this relatively small region contains roughly as much gas as the entire Milky Way<\/a>.<\/p>\n Webb reveals the hidden structure<\/p>\n Dust presents a major challenge when astronomers study galaxies. Thick clouds can block visible light, concealing stars and other structures.<\/p>\n Infrared observations help researchers investigate regions that would otherwise remain difficult to see.<\/p>\n For this image, Webb combined observations from its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI).<\/p>\n Together, these instruments reveal different aspects of Arp 220, including its bright central regions and the material extending outward from the merger.<\/p>\n The brilliant spikes radiating from the center are especially noticeable. They are diffraction spikes, an optical effect produced when intense light interacts with the telescope\u2019s structure.<\/p>\n The reddish-orange streams and filaments trace material associated with the galaxies, including carbon-rich organic molecules.<\/p>\n Meanwhile, faint blue structures near the outskirts reveal tidal tails, streams of material pulled away by the gravitational forces of the merger.<\/p>\n These features help astronomers reconstruct how the two galaxies<\/a> have interacted over time.<\/p>\n The remains of exploding stars<\/p>\n The intense star formation in Arp 220 also means that massive stars can reach the ends of their lives in a relatively short astronomical time.<\/p>\n Some explode as supernovae, releasing tremendous energy and scattering newly formed elements into surrounding space.<\/p>\n Radio telescope observations have identified approximately 100 supernova remnants within a region less than 500 light-years across.<\/p>\n That concentration provides further evidence of the extraordinary stellar activity occurring near the galactic centers.<\/p>\n Supernovae also influence their surroundings. Their expanding shock waves can heat gas, redistribute material, and affect the formation of subsequent generations of stars.<\/p>\n In a crowded environment like Arp 220, these processes take place alongside the gravitational forces driving the merger.<\/p>\n Why astronomers study merging galaxies<\/p>\n Galactic mergers<\/a> are an important part of cosmic evolution.\u00a0<\/p>\n Over billions of years, interactions between galaxies can alter their shapes, change their star formation rates, and influence the growth of the supermassive black holes at their centers.<\/p>\n Arp 220 is particularly valuable because it is relatively nearby by cosmic standards.<\/p>\n Its distance of 250 million light-years places it in the constellation Serpens, the Serpent. It is the closest known ultraluminous infrared galaxy.<\/p>\n Its name comes from astronomer Halton Arp\u2019s Atlas of Peculiar Galaxies, a catalog of unusual-looking galaxies and interacting systems.<\/p>\n The object appears as entry number 220, reflecting its distinctive structure and history.<\/p>\n By comparing observations from Webb, Hubble, and radio telescopes, scientists can investigate different layers of this complex system.<\/p>\n Each wavelength reveals information that the others cannot, helping researchers build a more complete picture of the collision.<\/p>\n A glimpse into the future of galaxies<\/p>\n The image of Arp 220 captures a transformation that is still unfolding.<\/p>\n Two galaxies that once existed separately are gradually becoming one, while their combined gas supplies fuel intense star formation.<\/p>\n Over time, that activity will change as the available gas is consumed, dispersed, or redistributed.<\/p>\n Our own Milky Way has also experienced galactic interactions throughout its history, and encounters between galaxies continue to shape the universe<\/a> today.<\/p>\n Arp 220 shows just how dramatic those changes can become.<\/p>\n What appears in Webb\u2019s image as a single brilliant object is actually the result of hundreds of millions of years of gravitational interaction, stellar birth, and destruction.<\/p>\n Image Credit: NASA\/ESA\/CSA\/STScI<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Arp 220 is one of the brightest infrared galaxies in the nearby universe, with intense star formation fueled…\n","protected":false},"author":2,"featured_media":656952,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[85,46,141,145],"class_list":["post-656951","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-il","tag-israel","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/656951","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=656951"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/656951\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/656952"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=656951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=656951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=656951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}