By chance, a collision [
http://csep10.phys.…colliding.html ] of two galaxies has created a surprisingly recognizable shape on a cosmic scale - The Cartwheel Galaxy [
http://hubblesite.o…1995/02 ]. The Cartwheel is part of a group of galaxies about 400 million light years away in the constellation Sculptor [
http://hawastsoc.or…] (two smaller galaxies in the group are visible below and left). Its rim is an immense ring-like structure over 100,000 light years in diameter, composed of star forming regions filled with extremely bright, massive stars. When galaxies collide [
http://www.astro.um…interact.html ] they pass through [
http://burro.astr.c…] each other, their individual stars do not come into contact. However, this ring-like shape is the result of gravitational [
http://www.public.i…section1.html ] disruption caused by a smaller galaxy [
http://antwrp.gsfc.…] passing through a large one, compressing the interstellar gas and dust and causing a star formation wave to move out like a ripple across the surface of a pond. This false-color composite [
http://chandra.harv…] image of the Cartwheel Galaxy is from space-based observatories. The Chandra X-ray Observatory data is [
http://arxiv.org/ab…] in purple, the Galaxy Evolution Explorer [
http://www.galex.ca…] ultraviolet view is in blue, the Hubble Space Telescope visible [
http://imagine.gsfc…emspectrum.html ] light picture is in green and the Spitzer Space Telescope infrared [
http://coolcosmos.i…] image is in red.
Explanation
By chance, a collision [
http://csep10.phys.…colliding.html ] of two galaxies has created a surprisingly recognizable shape on a cosmic scale - The Cartwheel Galaxy [
http://hubblesite.o…1995/02 ]. The Cartwheel is part of a group of galaxies about 400 million light years away in the constellation Sculptor [
http://hawastsoc.or…] (two smaller galaxies in the group are visible below and left). Its rim is an immense ring-like structure over 100,000 light years in diameter, composed of star forming regions filled with extremely bright, massive stars. When galaxies collide [
http://www.astro.um…interact.html ] they pass through [
http://burro.astr.c…] each other, their individual stars do not come into contact. However, this ring-like shape is the result of gravitational [
http://www.public.i…section1.html ] disruption caused by a smaller galaxy [
http://antwrp.gsfc.…] passing through a large one, compressing the interstellar gas and dust and causing a star formation wave to move out like a ripple across the surface of a pond. This false-color composite [
http://chandra.harv…] image of the Cartwheel Galaxy is from space-based observatories. The Chandra X-ray Observatory data is [
http://arxiv.org/ab…] in purple, the Galaxy Evolution Explorer [
http://www.galex.ca…] ultraviolet view is in blue, the Hubble Space Telescope visible [
http://imagine.gsfc…emspectrum.html ] light picture is in green and the Spitzer Space Telescope infrared [
http://coolcosmos.i…] image is in red.
Explanation
