The universe is still a mystery. We know what about 5 percent of the universe consists of. The rest is simply unknown. Researchers have gotten as far as knowing that a major portion, about 23 percent of the universe consists of a new kind of matter. No one has seen this matter, and no one knows what it consists of. The remaining roughly 72 percent of the universe is made up of something even more enigmatic, called dark energy.
Jan Conrad and Maja Llena Garde are scientists at Fysikum, Stockholm University and the Oskar Klein Center for Cosmoparticle Physics, and they are part of the international research team that has taken a giant step toward finding dark matter with the help of a new method.
“With our new method, for the first time we have been able to exclude models regarded by many as the most natural ones. Previous attempts did not achieve the same sensitivity. What’s more, our results are especially reliable,” says Jan Conrad.
“We can’t see dark matter because it doesn’t interact with the matter we know about. Nor does it emit any light. It’s virtually invisible. But we can determine that it affects the matter we’re familiar with.”
“We see how the rotation of galaxies is affect by something that weighs a lot but is invisible. We also see how the gas in galaxy clusters doesn’t move as it would if there were only visible matter present. So we know it’s there. The question is simply what it is. Many theoretical models have been developed to predict particles that meet the requirements for being identified as dark matter. But experiments are needed if we are to determine whether any of these models are correct,” says Jan Conrad.
Since dark matter is invisible, we can only see traces of it, and one way to do this is to look at light with extremely high energy, so-called gamma radiation. With the help of the satellite-borne Fermi Large Area Telescope, scientists can study gamma radiation and look for traces of dark matter.
“We’ve looked at gamma radiation from dwarf galaxies. These galaxies are small and dim, but extremely massive, so they seem to consist largely of dark matter. Unfortunately we still haven’t detected a gamma signal from the dark matter in these objects, but we are definitely getting closer. Our new method involves looking at several dwarf galaxies at the same time and combining the observations in a new way, which yields excellent results. This is an exciting time for dark matter research, because we’re getting closer and closer,” says Maja Llena Garde.
“This is truly a giant step forward in our pursuit of dark matter,” says the director of the Oskar Klein Center, Lars Bergström. “With my colleague Joakim Edsjö, I’ve studied these processes theoretically for more than ten years, but this is the first time important experimental breakthroughs are being seen. Now we just hope that Jan, Maja, and the Fermi team will continue this exciting quest using their new method.”
The research team’s findings are being published in the journal Physical Review Letters under the title “Constraining dark matter models from a combined analysis of Milky Way satellites with the Fermi Large Area Telescope.”Further information:
Jan Conrad, associate professor, Fysikum, Stockholm University, e-mail: firstname.lastname@example.org, phone: +46-8-55378769
Linnea Bergnéhr | idw
IceCube experiment finds Earth can block high-energy particles from nuclear reactions
24.11.2017 | Penn State
New proton record: Researchers measure magnetic moment with greatest possible precision
24.11.2017 | Johannes Gutenberg-Universität Mainz
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences