Mergers and Acquisitions

galactic_mergerSeveral telescopes have teamed up to examine a rare and massive merger of two galaxies that took place when the universe was just 3 billion years old (that was over 10 billion years ago). The galaxies, collectively called HXMM01, were creating a couple of thousand new star a year as they merged. These days, our galaxy, the Milky Way, hatches about two to three a year. The total number of stars in both colliding galaxies averages is around 400 billion.

The Herschel Space Observatory first spotted the collision in images taken with infrared light (the image at left). Follow-up observations from other telescopes showed the extreme degree of star-formation taking place in the merger.

The merging galaxies are circled in the close up view (on the right). The red data from the Smithsonian Astrophysical Observatory’s Submillimeter Array atop Mauna Kea, Hawaii, show dust-enshrouded regions of star formation. The green data, taken by the National Radio Astronomy Observatory’s Very Large Array, near Socorro, N.M., show carbon monoxide gas in the galaxies.

Blue shows visible starlight. The blue blobs outside of the circle are galaxies located closer to us as seen via near-infrared light observations are from the Hubble Space Telescope and the W.M. Keck Observatory atop Mauna Kea, Hawaii.

Image credit: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO