Evolution of Milky Way-like Galaxies

The images below show how galaxies similar in mass to our home galaxy, the Milky Way, evolved over time. The images taken by the NASA/ESA Hubble Space Telescope reveal that Milky Way-like galaxies grow larger in size and in stellar mass over billions of years. These images are part of the most comprehensive multi-observatory galaxy surveys yet. Stretching back in time more than 10 billion years, the census contains nearly 2 000 snapshots of Milky Way-like galaxies.

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 Near-infrared Deep Extragalactic Legacy Survey (CANDELS).

For an explanation of the z values quoted below, see this Redshift article.

11.3 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 11.3 billion years ago. Links: NASA press release A firestorm of star birth (artist’s illustration) The growth of Milky Way-like galaxies over time Hubble galaxy at redshift z = 0.26 Hubble galaxy at redshift z = 0.65 Hubble galaxy at redshift z = 1.3 Hubble galaxy at redshift z = 2.0 Hubble galaxy at redshift z = 2.4

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 11.3 billion years ago. Z=2.8

The image above reveals a compact, youthful galaxy as it looked 11.3 billion years ago, when our Universe was only about 2.5 billion years old. The bluish-white glow reveals that the fledgling galaxy is undergoing a wave of star birth, as its rich reservoir of gas compresses under gravity, creating myriad stars.

10.9 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 10.9 billion years ago.

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 10.9 billion years ago. z=2.4

10.3 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 10.3 billion years ago.

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 10.3 billion years ago. z=2.0

At 10.3 billion years ago, the firestorm of star birth is reaching its peak. The stellar “baby boom” churned out stars 30 times faster than the Milky Way does today. The galaxy’s yellowish colour most likely highlights ongoing star formation that is being obscured by dust and gas.

8.9 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 8.9 billion years ago.

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 8.9 billion years ago. z=1.3

Eventually, the galaxies exhaust their star-making gas. The galaxy at 8.9 billion years ago (image above) has developed a spiral shape, and the oldest stars reside in its central region.

6.1 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 6.1 billion years ago.

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 6.1 billion years ago. z=0.65

By 6.3 billion years ago this similar galaxy had grown even larger. The galaxy was dominated by mostly older stars, which can be seen in its reddish appearance.

3.1 Billion Years Ago

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 3.1 billion years ago.

This image, taken by the NASA/ESA Hubble Space Telescope, shows a galaxy similar in mass to the Milky Way. The galaxy is seen as it was 3.1 billion years ago. z=0.26

At 3,1 billion years ago this galaxy had clearly visible spiral arms dotted with clouds of gas lit by newly formed open star clusters.

References

NASA Composite Image

Reconstruction of 10 billion year old Milky Way


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Evolution of Milky Way-like Galaxies — 1 Comment

  1. Pingback: Reconstruction of Early Milky Way | History of the Universe News

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