Scientists have known for several years that galaxies in the nearby universe seem to fall into one of these two states. But a new survey of the distant universe shows that even very young galaxies as far away as 12 billion light years are either awake or asleep as well, meaning galaxies have behaved this way for more than 85 percent of the history of the universe. (Looking at galaxies farther away is like looking back in time when they were much younger, because of how long it takes the light they emit to reach us here on Earth.)
“The fact that we see such young galaxies in the distant universe that have already shut off is remarkable,” said Kate Whitaker, a Yale University graduate student and lead author of the paper, which is published in the June 20 online edition of the Astrophysical Journal.
In order to determine whether the galaxies were asleep or awake, Whitaker and her colleagues fabricated a new set of filters, each one sensitive to different wavelengths of light, which they used on a 4-meter Kitt Peak telescope in Arizona. They spent 75 nights peering into the distant universe and collecting light from 40,000 galaxies ranging in distance from the nearby universe out to 12 billion light years away. The resulting survey is the deepest and most complete ever made at those distances and wavelengths of light.
The team deciphered the galaxies’ dual behavior based on the color of the light they emit. Because of the physics of star formation, active, wakeful galaxies appear bluer, while the light emitted by passive, sleepy galaxies tends toward the redder end of the spectrum.
The researchers found that there are many more active galaxies than passive ones, which agrees with the current thinking that galaxies start out actively forming stars before eventually shutting down.
“We don’t see many galaxies in the in-between state,” said Pieter van Dokkum, a Yale astronomer and another author of the paper. “This discovery shows how quickly galaxies go from one state to the other, from actively forming stars to shutting off.”
Whether the sleeping galaxies have completely shut down remains an open question, Whitaker said. However, the new study suggests the active galaxies are forming stars at rates about 50 times greater than their sleepy counterparts.
“Next, we hope to determine whether galaxies go back and forth between waking and sleeping or whether they fall asleep and never wake up again,” van Dokkum said. “We’re also interested in how long it takes galaxies to fall asleep, and whether we can catch one in the act of dozing off.”
Other authors of the study include Ivo Labbé (Leiden University and Carnegie Observatories); Gabriel Brammer (Yale University and European Southern Observatory); Mariska Kriek (Princeton University and Harvard-Smithsonian Center for Astrophysics); Danilo Marchesini (Tufts University); Ryan Quadri and Marijn Franx (Leiden University); Adam Muzzin, Rachel Bezanson, Kyoung-Soo Lee, Britt Lundgren, Erica Nelson, Tomer Tal and David Wake (Yale University); Rik Williams (Carnegie Observatories); Garth Illingworth (UCO/Lick Observatory); and Gregory Rudnick (University of Kansas).
PRESS CONTACT: Suzanne Taylor Muzzin 203-432-8555
Suzanne Taylor Muzzin | EurekAlert!
NASA laser communications to provide Orion faster connections
30.03.2017 | NASA/Goddard Space Flight Center
Pinball at the atomic level
30.03.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering