Some of the most cataclysmic and mysterious events in the cosmos only reveal themselves by their gravitational waves. We’ve detected some of them with our ground-based detectors, but the size of these detectors is limited. The next step forward in gravitational wave (GW) astronomy is a space-based detector: LISA, the Laser Interferometer Space Antenna.
Continue reading “NASA is Building Telescopes for the LISA Mission”The Milky Way’s Supermassive Black Hole Might Have Formed 9 Billion Years Ago
Large galaxies like ours are hosts to Supermassive Black Holes (SMBHs.) They can be so massive that they resist comprehension, with some of them having billions of times more mass than the Sun. Ours, named Sagittarius A* (Sgr A*), is a little more modest at about four million solar masses.
Astrophysicists have studied Sgr A* to learn more about it, including its age. They say it formed about nine billion years ago.
Continue reading “The Milky Way’s Supermassive Black Hole Might Have Formed 9 Billion Years Ago”Scientists Develop a Novel Method for Detecting Supermassive Black Holes: Use Smaller Black Holes!
In 1974, astronomers Bruce Balick and Robert L. Brown discovered a powerful radio source at the center of the Milky Way galaxy. The source, Sagittarius A*, was subsequently revealed to be a supermassive black hole (SMBH) with a mass of over 4 million Suns. Since then, astronomers have determined that SMBHs reside at the center of all galaxies with highly active central regions known as active galactic nuclei (AGNs) or “quasars.” Despite all we’ve learned, the origin of these massive black holes remains one of the biggest mysteries in astronomy.
The most popular theories are that they may have formed when the Universe was still very young or have grown over time by consuming the matter around them (accretion) and through mergers with other black holes. In recent years, research has shown that when mergers between such massive objects occur, Gravitational Waves (GWs) are released. In a recent study, an international team of astrophysicists proposed a novel method for detecting pairs of SMBHs: analyzing gravitational waves generated by binaries of nearby small stellar black holes.
Continue reading “Scientists Develop a Novel Method for Detecting Supermassive Black Holes: Use Smaller Black Holes!”A Solution to the “Final Parsec Problem?”
Supermassive Black Holes are Nature’s confounding behemoths. It’s difficult for Earth-bound minds to comprehend their magnitude and power. Astrophysicists have spent decades studying them, and they’ve made progress. But one problem still baffles even them: the Final Parsec Problem.
New research might have solved the problem, and dark matter plays a role in the solution.
Continue reading “A Solution to the “Final Parsec Problem?””Primordial Black Holes Can Only Explain a Fraction of Dark Matter
What is Dark Matter? That question is prominent in discussions about the nature of the Universe. There are many proposed explanations for dark matter, both within the Standard Model and outside of it.
One proposed component of dark matter is primordial black holes, created in the early Universe without a collapsing star as a progenitor.
Continue reading “Primordial Black Holes Can Only Explain a Fraction of Dark Matter”Merging Black Holes Could Give Astronomers a Way to Detect Hawking Radiation
Nothing lasts forever, including black holes. Over immensely long periods of time, they evaporate, as will other large objects in the Universe. This is because of Hawking Radiation, named after Stephen Hawking, who developed the idea in the 1970s.
The problem is Hawking Radiation has never been reliably observed.
Continue reading “Merging Black Holes Could Give Astronomers a Way to Detect Hawking Radiation”Here’s Why We Should Put a Gravitational Wave Observatory on the Moon
Scientists detected the first long-predicted gravitational wave in 2015, and since then, researchers have been hungering for better detectors. But the Earth is warm and seismically noisy, and that will always limit the effectiveness of Earth-based detectors.
Continue reading “Here’s Why We Should Put a Gravitational Wave Observatory on the Moon”Black Holes Need Refreshing Cold Gas to Keep Growing
The Universe is filled with supermassive black holes. Almost every galaxy in the cosmos has one, and they are the most well-studied black holes by astronomers. But one thing we still don’t understand is just how they grew so massive so quickly. To answer that, astronomers have to identify lots of black holes in the early Universe, and since they are typically found in merging galaxies, that means astronomers have to identify early galaxies accurately. By hand. But thanks to the power of machine learning, that’s changing.
Continue reading “Black Holes Need Refreshing Cold Gas to Keep Growing”Next Generation Gravitational Wave Observatories Could Detect 100-600 Solar Mass Black Hole Mergers
Humans are born wonderers. We’re always wondering about the next valley over, the next horizon, what we’ll understand next about this vast Universe that we’re all wrapped up in.
In 2015, we finally detected our first long-awaited and long-theorized gravitational wave from the distant merger of two stellar mass black holes. But now we want to know more, and only better detectors can feed our appetite.
Continue reading “Next Generation Gravitational Wave Observatories Could Detect 100-600 Solar Mass Black Hole Mergers”Ultra-Massive Black Holes: How Does the Universe Produce Objects So Massive?
Black holes are the most massive objects that we know of in the Universe. Not stellar mass black holes, not supermassive black holes (SMBHs,) but ultra-massive black holes (UMBHs.) UMBHs sit in the center of galaxies like SMBHs, but they have more than five billion solar masses, an astonishingly large amount of mass. The largest black hole we know of is Phoenix A, a UMBH with up to 100 billion solar masses.
How can something grow so massive?
Continue reading “Ultra-Massive Black Holes: How Does the Universe Produce Objects So Massive?”