The evolution of our galaxy, the Milky Way, has been pieced together from pictures taken by NASA and ESA telescopes, according to a research by Texas A&M students.
Lead author Casey Papovich, said in a press release that by looking at distant galaxies, the researchers managed to observe how they looked when their light left for Earth.
“Because the galaxies are billions of light-years distant, we can see how they looked billions of years in the past”, added Papovich, who, together with postdoctoral researchers Vithal Tilvi and Ryan Quadri and almost 25 astronomers around the world spent a year examining distant galaxies similar in mass to the Milky Way.
Two programs were used to discover the most suitable galaxies, the deep sky surveys of the universe called FourStar Galaxy Evolution Survey (ZFOURGE) and Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS).
The group studied more than 24,000 galaxies from the combined catalog to identify representative galaxies that had an evolving pattern similar to our Milky Way. In the next step, the scientists made a projection of how those galaxies expanded over time, which could be used just like a “film” of the Milky Way’s life from youth to middle age.
“Most stars today exist in galaxies like the Milky Way, so by studying how galaxies like our own formed, we have come to understand the most typical locations of stars in the universe. We now have the best picture of how galaxies like our own formed their stars,” said Papovich, an associate professor in the Department of Physics and Astronomy.
Papovich mentioned the research data clearly shows that the Milky Way got trough its most rapid phase of growth around 9.2 and 10 billion years ago, producing new stars at an incredible rate, approximately 30 times faster compared to today’s rhythm. In present times, the Milky Way churns out one new star per year, compared to a production of 30 each year 9.5 billion years ago. The study revealed a strong bond between star formation and growth in galaxy size.
Papovich explained that our Sun is one of the more recently formed stars, born around 5 billion years ago, a period when star formation within the Milky Way had toned down to a level that is also found today. The Sun’s late appearance may have been a good thing, allowing the growth of the planets within our solar system.
The study was supported by funding from National Science Foundation and NASA, who allowed the use of its Hubble and Spitzer Space Telescopes. In order to carry out the research, the scientists also used ground-based telescopes, including the Las Campanas Observatory in Chile and the Magellan Baade Telescope, but also European Space Agency’s Herschel Space Observatory.
Image Source: The Next Web