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!
Astronomers release most complete ultraviolet-light survey of nearby galaxies
18.05.2018 | NASA/Goddard Space Flight Center
A quantum entanglement between two physically separated ultra-cold atomic clouds
17.05.2018 | University of the Basque Country
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology