Lifeboat Foundation

Gas outflows are common features of active supermassive black holes that reside in the center of large galaxies. Millions to billions of times the mass of the Sun, these black holes feed on the large disks of gas that swirl around them. Occasionally the black holes eat too much and burp out an ultra-fast wind, or outflow. These winds may have a strong influence on regulating the growth of the host galaxy by clearing the surrounding gas away and suppressing star formation.

Scientists have now made the most detailed observation yet of such an outflow, coming from an active galaxy named IRAS 13224–3809. The outflow’s temperature changed on time scales of less than an hour, which is hundreds of times faster than ever seen before. The rapid fluctuations in the outflow’s temperature indicated that the outflow was responding to X-ray emissions from the accretion disk, a dense zone of gas and other materials that surrounds the black hole.

The new observations are published in the journal Nature on March 2, 2017.

A Yale-led team has produced one of the highest-resolution maps of dark matter ever created, offering a detailed case for the existence of cold dark matter—sluggish particles that comprise the bulk of matter in the universe.

The dark matter map is derived from Hubble Space Telescope Frontier Fields data of a trio of galaxy clusters that act as cosmic magnifying glasses to peer into older, more distant parts of the universe, a phenomenon known as gravitational lensing.

Yale astrophysicist Priyamvada Natarajan led an international team of researchers that analyzed the Hubble images. “With the data of these three lensing clusters we have successfully mapped the granularity of dark matter within the clusters in exquisite detail,” Natarajan said. “We have mapped all of the clumps of dark matter that the data permit us to detect, and have produced the most detailed topological map of the dark matter landscape to date.”

NASA’s Fermi Gamma-ray Space Telescope has found a signal at the center of the neighboring Andromeda galaxy that could indicate the presence of the mysterious stuff known as dark matter. The gamma-ray signal is similar to one seen by Fermi at the center of our own Milky Way galaxy.

Gamma rays are the highest-energy form of light, produced by the universe’s most energetic phenomena. They’re common in galaxies like the Milky Way because cosmic rays, particles moving near the speed of light, produce gamma rays when they interact with interstellar gas clouds and starlight.

Surprisingly, the latest Fermi data shows the gamma rays in Andromeda—also known as M31—are confined to the galaxy’s center instead of spread throughout. To explain this unusual distribution, scientists are proposing that the emission may come from several undetermined sources. One of them could be dark matter, an unknown substance that makes up most of the universe.

While cosmologists may be fascinated by what dark matter does, particle physicists are fascinated by what dark matter is. For us, dark matter should be—naturally—a particle, albeit one that is still lurking hidden in our data. For the last few decades, we’ve had a tantalizing guess as to what this particle might be—namely, the lightest of a new class of supersymmetric particles. Supersymmetry is an extension to the Standard Model of particles and forces that nicely addresses lingering questions about the stability of the mass of the Higgs boson, the unification of the forces, and the particle nature of dark matter. In fact, supersymmetry predicts a vast number of new particles—one for each particle we already know about. Yet while one of those new particles could constitute dark matter, to many of us that would be just a happy byproduct.

But after analyzing data from the first (2010–2012) and second (2015–2018) runs of the Large Hadron Collider (LHC), we haven’t found supersymmetric particles yet—indeed, no new particles at all, beyond the Higgs boson. So, while we continue to hunt for supersymmetry, we’re also taking a fresh look at what our cosmology colleagues can tell us about dark matter. It is the strongest experimental evidence for new physics beyond the Standard Model, after all.

In fact, some might say that a principal goal of the LHC and future colliders will be to create and study dark matter. For that to happen, there must be a means for the visible universe and the dark universe to communicate with each other. In other words, the constituents of the particles that we collide must be capable of interacting with the putative dark-matter particles via fundamental forces. A force requires a force carrier, or boson. The electromagnetic force is carried by the photon, the weak nuclear force by so-called vector bosons, and so on. Interactions between dark matter and normal matter should be no different: They could happen by exchanging dark bosons.

Continue reading “If You Can’t Find Dark Matter, Look First for a Dark Force” »

NASA’s Fermi Telescope has looked at the gamma-ray emission of M31, the Andromeda Galaxy, and discovered the largest fraction of this powerful radiation comes from the core of the galaxy, very much like in our own Milky Way. The international team of researchers has considered this signature as potential indirect evidence of dark matter.

Some theoretical models predict gamma-ray emissions when dark matter particles interact with each other. Dark matter doesn’t like interacting at all, it doesn’t form clumps or clouds, so these gamma-ray signals might only happen in dense regions, like at the core of galaxies.

Continue reading “A Potential Dark Matter Signature Has Been Seen in The Andromeda Galaxy” »

Twenty years after the project began, scientists think they are now just weeks away from receiving their first picture of a black hole.

The numbers behind the creation of the Event Horizon Telescope (EHT) are mind boggling enough, let alone the thought of what it might see on April 5 when it’s trained on Sagittarius A*, the supermassive black hole at the centre of our galaxy.

It’s 26,000 light years from Earth. Even though its “edge” is 20-odd million kilometres across, EHT team members say seeing it is still like trying to pinpoint a grapefruit on the Moon.

Continue reading “Scientists might be just weeks away from taking the first real picture of a black hole” »

Black holes are among the most fascinating objects in the known Universe. But despite the fact that they’re suspected to lurk at the centre of most galaxies, the reality is that no one has ever been able to actually photograph one.

That’s because black holes, as their name implies, are very, very dark. They’re so massive that they irreversibly consume everything that crosses their event horizon, including light, making them impossible to photograph. But that could be about to change, when a new telescope network switches on in April this year.

Called the Event Horizon Telescope, the new device is made up of a network of radio receivers located across the planet, including at the South Pole, in the US, Chile, and the French alps.

Continue reading “Scientists Are About to Switch on a Telescope That Could Photograph a Black Hole’s Event Horizon” »

The Universe as we know it is made up of a continuum of space and time — a space-time fabric that’s curved by massive objects such as stars and black holes, and which dictates the movement of matter.

Thanks to Einstein’s gravitational waves, we know disturbances can propagate through both space and time. But what’s less understood is exactly how that happens when properties of the fabric is continuously shifting.

Continue reading “Brand New Maths Could Finally Explain How Disturbances Propagate Through Space-Time” »

Dr Mike McCulloch says his theory explains why galaxies are not ripped apart, without needing dark matter.