Scientists still research and make new discoveries and theories about origin of life on Earth. Along with this there is a growing curiosity among the scientists to find out more about our own galaxy, the Milky Way. The Milky Way gets its name because of its dim “milky” glowing band arching across the night sky. Our solar system is located within the disk of the Milky Way.
Recent findings which used tadpole galaxies have shed new light as to what was responsible for the creation of giant spiral galaxies like Andromeda and the Milky Way. They grew so large both by swallowing lesser galaxies and by grabbing gas from the space around them. New observations of exotic “tadpole” galaxies are shedding light on how the Milky Way assembled its most luminous component: the starry disk that is home to the sun and Earth.
First spotted in the 1990s, tadpole galaxies sport bright heads, which spawn brilliant new stars, and long, faint tails. Most tadpoles are billions of light years distant, meaning they were more common when the universe was young. From such great distances, though, studying the odd galaxies is difficult.
Thus, Jorge Sánchez Almeida of the Astrophysics Institute of the Canary Islands and his colleagues scrutinized seven rare tadpoles that happen to lie much closer, within 600 million light years of Earth. Analyzing light from telescopes on the island of La Palma, the astronomers determined the speeds of different parts of each galaxy, demonstrating that most of the tadpoles rotate, just as the disks of spiral galaxies do. The astronomers also got a shock, however.
In the Milky Way, oxygen abounds most in the bright star rich central regions where massive stars forge oxygen and expel it when they explode. Yet the tadpoles exhibited the opposite oxygen pattern: their brilliant heads had less oxygen than their faint tails. “This is very strange,” Sánchez Almeida says.
To explain the surprising discovery, published April 10 in the Astrophysical Journal, the astronomers invoke pristine intergalactic gas, little altered since the big bang, the primordial inferno that produced only elements much lighter than oxygen. In this scenario, a stream of oxygen poor gas slams into one section of a nascent galactic disk and triggers the birth of bright new stars, which light a tadpole’s head but harbor little oxygen.
If this idea is right, celestial tadpoles resemble their terrestrial namesakes: they are primitive creatures that are growing larger. “The Milky Way could have done this,” says team member Bruce Elmegreen of IBM Research, who thinks tadpoles show how, billions of years ago, giant spiral galaxies gathered gas from their surroundings and built their spinning disks of stars, which ultimately grew into galactic superpowers like the Milky Way.
As we continue our journey into the realms of space many more interesting findings are sure to come our way. These discoveries will surely help space researchers in exploring the galaxies which are still not found as well as the earth-like exoplanets which could be well existing with life in them.
