James Webb Space Telescope Captures Stunning Image of Arp 220
Infrared light captured by the Webb telescope shows the spectacular collision of two spiral galaxies known as Arp 220. This cosmic crash resulted in an astonishing burst of star formation, with each galactic core surrounded by a luminous ring of newly-formed stars. The combined light of these stars is so intense that it outshines more than a trillion suns, creating a striking spiked feature that dominates the image. Credits: NASA, ESA, CSA, STScI, and Alyssa Pagan from STScI.
April 17, 2023
NASA's James Webb Space Telescope has captured a stunning image of Arp 220, two spiral galaxies in the process of merging. Arp 220 shines like a beacon in the night sky and is the nearest ultra-luminous infrared galaxy (ULIRG) to Earth. It is located 250 million light-years away in the constellation of Serpens. Arp 220 glows brightest in infrared light, making it an ideal target for the James Webb Space Telescope. It has a luminosity of over a trillion suns, making it much brighter than our Milky Way galaxy, which has a modest luminosity of around ten billion suns. The collision of the two spiral galaxies began about 700 million years ago and sparked an enormous burst of star formation. Around 200 huge star clusters reside in a packed, dusty region about 5,000 light-years across, which is equivalent to all the gas in the entire Milky Way galaxy.
NASA's Hubble Space Telescope had previously uncovered the cores of the parent galaxies, which are 1,200 light-years apart. Each core has a rotating, star-forming ring that blasts out dazzling infrared light, creating diffraction spikes visible in the Webb image. The Webb image also reveals faint tidal tails, or material drawn off the galaxies by gravity, represented in blue. Organic material is visible in reddish-orange streams and filaments across Arp 220.
Webb viewed Arp 220 with its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). The previous radio telescope observations had revealed around 100 supernova remnants in an area of less than 500 light-years. Arp 220 is one of the most intensely studied galaxies in the universe. It was first discovered by Halton Arp in 1966 and added to his "Atlas of Peculiar Galaxies," a catalog of unusual and interesting galaxies. The merger of the two spiral galaxies that created Arp 220 is an important process in the evolution of galaxies. When galaxies merge, they trigger intense bursts of star formation and create new structures such as rings and tidal tails. These processes can also trigger the growth of supermassive black holes at the centers of the galaxies.
Arp 220 is also an important source of information about the early universe. Because it is so distant, its light has been traveling towards us for millions of years, giving astronomers a glimpse into the past. By studying galaxies like Arp 220, astronomers can learn about the conditions in the early universe and how galaxies have evolved over time.
The James Webb Space Telescope is a powerful tool for studying galaxies like Arp 220. Its advanced instruments can observe the universe in infrared light, which can penetrate dusty regions and reveal new details about the processes happening within galaxies.
In addition to the supernova remnants and star clusters mentioned in the article, Arp 220 also contains a large amount of molecular gas, which is the raw material for star formation. The presence of so much gas indicates that Arp 220 may continue to form new stars for millions of years to come.