Astronomers discover stars in early galaxies had a need for speed
The finding offers new insights into how these early galaxies may have evolved into the more familiar ones we see in the nearby universe.
The team spent an unprecedented 29 hours observing the galaxy with one of the largest telescopes on Earth—the Gemini South Telescope in Chile—to collect enough light to determine how fast its stars are moving.
Because stars' velocities are directly related to the mass they are orbiting, the ultra-fast speeds would ordinarily suggest the galaxy is very large. But additional observations from the Hubble Space Telescope showed that the galaxy is in fact much smaller than expected, with a diameter of about 5000 light years.
“This result is surprising, as the galaxy itself is extremely small,” said Pieter van Dokkum, professor of astronomy and physics at Yale University and lead author of the paper, which appears in the August 6 issue of Nature. “We do find stars with comparable speeds in mature galaxies in today's nearby universe, but those galaxies are typically many tens of thousands of light years across. Here we have a very small galaxy in the young universe whose stars behave as if they were in a giant galaxy.”
Because the galaxy is 11 billion light years away, the light it emitted took 11 billion years to reach us on Earth. That means we see the galaxy as it was when the universe was only three billion years old, compared to its current age of 14 billion years.
One of the big riddles is how such extreme galaxies form so quickly, and why we don't see any in today's nearby universe. “It's possible these are the seeds that grow and evolve into the more massive galaxies we see closer to home,” van Dokkum said.
The team hopes to look back even further in space and time to see these types of galaxies as they were first forming. “The ancestors of these extreme galaxies should have quite spectacular properties, as they must have formed a huge amount of stars in a relatively short amount of time,” van Dokkum said.
Other authors of the paper include Mariska Kriek (Princeton University) and Marijn Franx (Leiden Observatory).
Media Contact
More Information:
http://www.yale.eduAll latest news from the category: Physics and Astronomy
This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.
innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.
Newest articles
Superradiant atoms could push the boundaries of how precisely time can be measured
Superradiant atoms can help us measure time more precisely than ever. In a new study, researchers from the University of Copenhagen present a new method for measuring the time interval,…
Ion thermoelectric conversion devices for near room temperature
The electrode sheet of the thermoelectric device consists of ionic hydrogel, which is sandwiched between the electrodes to form, and the Prussian blue on the electrode undergoes a redox reaction…
Zap Energy achieves 37-million-degree temperatures in a compact device
New publication reports record electron temperatures for a small-scale, sheared-flow-stabilized Z-pinch fusion device. In the nine decades since humans first produced fusion reactions, only a few fusion technologies have demonstrated…
