Two colliding galaxies are lit up like a Christmas tree in a dazzling new NASA photo, brought to you by x-ray light! The image shows “ultra-luminous X-ray sources” (ULXs) studding the spiral galaxies NGC 2207 and IC 2163, which are which are grazing each other about 130 million light-years from Earth, in the constellation Canis Major.
According to NASA, the photo is a composite that combines data from three NASA spacecrafts — the Chandra X-ray Observatory, the Hubble Space Telescope, and the Spitzer Spce Telescope. The exact nature of ULXs isn’t known for sure, but astronomers believe they’re probably a special type of X-ray binary- a system in which a star circles either a black hole or a neutron star.
“The strong gravity of the neutron star or black hole pulls matter from the companion star. As this matter falls toward the neutron star or black hole, it is heated to millions of degrees and generates X-rays,” NASA officials said.
NGC 2207 and IC 2163 are active and exciting targets for astronomers. To date, researchers have counted 28 ULXs in the two galaxies, which have also been home to three supernova explosions in the last 15 years.
Galaxy collisions are known to spawn intense bouts of star birth, and indeed, NGC 2207 and IC 2163 are forming the equivalent of 24 new suns every year, compared to one to three suns per year in the Milky Way. The ULXs in NGC 2207 and IC 2163 likely contain very young stars, perhaps just 10 million years old or so, researchers said. Earth’s sun, in contrast, is 5 billion years old and is just about halfway through its life.
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