Research Details Unprecedented Life Story Of Milky Way Galaxy Evolution

This illustration depicts a view of the night sky from a hypothetical planet within the youthful Milky Way galaxy 10 billion years ago. The heavens are ablaze with a firestorm of star birth. Glowing pink clouds of hydrogen gas harbor countless newborn stars, and the bluishwhite hue of young star clusters litter the landscape.

(Credit: NASA, ESA and Z. Levay / STScI.)

Picture, if you will, the ultimate universal home movie if not parental keepsake and life story: our Milky Way Galaxy, starting out as but a wee collection of young stars some 12 billion years ago, continuously feeding on the gas of smaller nearby galaxies and undergoing a huge burst of star births to grow increasingly more massive, only to later fade out into the rather tame, large spiral galaxy we’ve come to inhabit today.

Despite many 21st century advances, from technology to social media apps, such a movie cannot be made. However, thanks to one of the most comprehensive multi-observatory galaxy surveys to date led by Texas A&M University’s Casey Papovich, astronomers have come up with the next best thing — the evolution of the Milky Way in pictures, pieced together using data from NASA and European Space Agency space telescopes and ground-based telescopes as well as thousands of snapshots of galaxies similar in mass to the Milky Way.

“As we look at distant galaxies, we see how they looked when their light left for Earth,” said Papovich, lead author on the international team’s science paper, which is published today in the April 10 issue of The Astrophysical Journal. “Because the galaxies are billions of light-years distant, we can see how they looked billions of years in the past.”

Papovich, along with Texas A&M postdoctoral researchers Vithal Tilvi and Ryan Quadri and roughly two dozen astronomers around the world, spent a year studying carefully selected distant galaxies similar in mass to the progenitor of our own Milky Way that were found in two deep-sky program surveys of the universe, the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and the FourStar Galaxy Evolution Survey (ZFOURGE). First, the group looked at the more than 24,000 galaxies included in the combined catalog to identify representative galaxies that evolved as our Milky Way did. Then, they made a sequence of how those galaxies grew over time to represent how our own galaxy would have evolved, in effect creating a “movie” 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’ve come to understand the most typical locations of stars in the universe,” said Papovich, an associate professor in the Department of Physics and Astronomy and a member of the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy since 2008. “We now have the best picture of how galaxies like our own formed their stars.”

For more information about this research, see the College of Science website.

This composite of Hubble Space Telescope images illustrates the evolution of Milky Waylike galaxies, as detailed in the most comprehensive, multiobservatory galaxy survey to date, led by Texas A&M University astronomer Casey Papovich. The six chronological images (beginning at far right) reveal that these galaxies each similar in mass to our Milky Way grow larger and rounder over time. As their stellar population ages, their colors change from blue to yellow to red as their collection of stars burns out in order of brightness. The images were taken between 2010 and 2012 with Hubble's Wide Field Camera 3 and Advanced Camera for Surveys as part of the Cosmic Assembly Nearinfrared Deep Extragalactic Legacy Survey

Photo credit: NASA, ESA, C.
Papovich / Texas A&M University, H.
Ferguson / STScI, S. Faber /
University of California, Santa Cruz
and I. Labbe / Leiden University

 

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About Research at Texas A&M University: As one of the world’s leading research institutions, Texas A&M is at the forefront in making significant contributions to the storehouse of knowledge, including that of science and technology. Research conducted at Texas A&M represented annual expenditures of more than $820 million in FY 2013, ranking Texas A&M in the top 20 of the National Science Foundation’s most recent survey of research and development expenditures among U.S. colleges and universities. Recently reported FY 2014 research expenditures exceed $854 million. That research creates new knowledge that provides basic, fundamental and applied contributions resulting in many cases in economic benefits to the state, nation and world. To learn more, visit http://research.tamu.edu.

Media contact: Shana K. Hutchins, (979) 862-1237 or shutchins@science.tamu.edu or Dr. Casey Papovich, (979) 862-2704 or papovich@physics.tamu.edu

 

 

 

 


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