Webb Successfully Captures the Breathtaking Galactic Merger Arp 220

Arp 220: The Ultra-Luminous Infrared Galaxy Captured by NASA’s James Webb Space Telescope

In a stunning display of cosmic beauty, Arp 220 shines like a beacon amidst a vast expanse of galaxies. This view from NASA’s James Webb Space Telescope captures the two spiral galaxies in the midst of a merger, emitting a brilliant infrared light that makes it an ideal target for Webb.

Located in the constellation of Serpens, Arp 220 is an ultra-luminous infrared galaxy (ULIRG) with a luminosity of more than a trillion suns. To put that into perspective, our Milky Way galaxy has a much more modest luminosity of about ten billion suns.

Arp 220 is the nearest ULIRG and the brightest of the three galactic mergers closest to Earth. The collision of the two spiral galaxies began about 700 million years ago, sparking an enormous burst of star formation. About 200 huge star clusters reside in a packed, dusty region about 5,000 light-years across, which is equivalent to about 5 percent of the Milky Way’s diameter. The amount of gas in this tiny region is equal to all of the gas in the entire Milky Way galaxy.

Previous radio telescope observations revealed about 100 supernova remnants in an area of less than 500 light-years. NASA’s Hubble Space Telescope uncovered the cores of the parent galaxies 1,200 light-years apart. Each of the cores has a rotating, star-forming ring blasting out dazzling infrared light that creates diffraction spikes – the starburst feature that dominates this image.

Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) captured Arp 220’s faint tidal tails or material drawn off the galaxies by gravity, represented in blue. Organic material represented in reddish-orange appears in streams and filaments across Arp 220.

Arp 220 is a breathtaking reminder of the beauty and complexity of our universe, and Webb’s view of this ultra-luminous infrared galaxy is a testament to the telescope’s incredible capabilities.