Black Holes Archives

November 9, 2023November 9, 2023 by Matt Williams

Sometimes Compact Galaxies Hide Their Black Holes

Illustration of an active quasar. What role does its dark matter halo play in activating the quasar? Credit: ESO/M. Kornmesser — Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

Quasars, short for quasi-stellar objects, are one of the most powerful and luminous classes of objects in our Universe. A subclass of active galactic nuclei (AGNs), quasars are extremely bright galactic cores that temporarily outshine all the stars in their disks. This is due to the supermassive black holes in the galactic cores that consume material from their accretion disks, a donut-shaped ring of gas and dust that orbit them. This matter is accelerated to close to the speed of light and slowly consumed, releasing energy across the entire electromagnetic spectrum.

Based on past observations, it is well known to astronomers that quasars are obscured by the accretion disk that surrounds them. As powerful radiation is released from the SMBH, it causes the dust and gas to glow brightly in visible light, X-rays, gamma-rays, and other wavelengths. However, according to a new study led by researchers from the Centre for Extragalactic Astronomy (CEA) at Durham University, quasars can also be obscured by the gas and dust of their entire host galaxies. Their findings could help astronomers better understand the link between SMBHs and galactic evolution.

November 6, 2023November 6, 2023 by Evan Gough

Roman Could Finally Tell Us if Primordial Black Holes Exist

An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to a black hole. Credit: Aaron Smith/TACC/UT-Austin. — An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to create black holes. Credit: Aaron Smith/TACC/UT-Austin.

When the Universe erupted into existence with the Big Bang, all of its matter was compressed into a tiny area. Cosmologists theorize that in some regions, subatomic matter may have been so tightly packed that matter collapsed into primordial black holes. If these primordial black holes exist, they’re small, and they could be hiding among the population of free-floating planets.

November 1, 2023November 1, 2023 by Evan Gough

Next Generation Gravitational Wave Observatories Could Detect 100-600 Solar Mass Black Hole Mergers

Simulation of merging supermassive black holes. Credit: NASA's Goddard Space Flight Center/Scott Noble — Simulation of merging supermassive black holes. New research shows how dark matter overcomes the Final Parsec Problem. Credit: NASA's Goddard Space Flight Center/Scott Noble

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.

October 27, 2023October 27, 2023 by Brian Koberlein

The Milky Way's Black Hole is Spinning as Fast as it Can

Simulation of glowing gas around a spinningblack hole. Credit: Chris White, Princeton University

Pick any object in the Universe, and it is probably spinning. Asteroids tumble end over end, planets and moons rotate on their axes, and even black holes spin. And for everything that spins, there is a maximum rate at which it can rotate. The black hole in our galaxy is spinning at nearly that maximum rate.

October 12, 2023October 12, 2023 by Evan Gough

New Stars Forming Uncomfortably Close to the Milky Way’s Supermassive Black Hole

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Astronomers examining a star cluster near Sgr A*, the Milky Way’s supermassive black hole, found that the cluster has some unusually young members for its location. That’s difficult to explain since the region so close to the powerful black hole is infused with powerful radiation and dominated by the black hole’s extremely powerful gravitational force. According to our understanding of stellar formation, young stars shouldn’t be there.

October 8, 2023October 8, 2023 by Brian Koberlein

Here's What it Would Take to See a Black Hole's Photon Ring

The EHT image of M87* compared to its photon ring. Credit: Left: EHT Collaboration, Right: A.E. Broderick et al, 2022

Supermassive black holes are elusive creatures. Massive gravitational beasts that can power immensely bright quasars, or can lurk quietly among the bright stars of a galactic core. We mostly study them indirectly through their bright accretion disks or powerful jets of plasma they create, but we have been able to observe them more directly, such as our images of M87* and Sag A*. But what still eludes us is capturing a direct image of the enigmatic photon ring. A new work in Acta Astronautica proposes how this might be done.

October 2, 2023October 2, 2023 by Brian Koberlein

It's Confirmed. M87's Black Hole is Actually Spinning

Schematic representation of the tilted accretion disk model. Credit: Cui et al. (2023), Intouchable Lab@Openverse and Zhejiang Lab

Fifty-five million light-years away, in the galaxy known as M87, lies a supermassive black hole. It is a powerfully active black hole with a mass of 6.5 billion Suns, and in 2019 it was the first black hole to be imaged directly. The radio image captured by the Event Horizon Telescope (EHT) shows a halo of ambient light warped by the black hole’s gravity and directed our way. On one side of the halo, the light is brighter, which according to general relativity is due to the rotation or spin of the black hole. It was the first direct confirmation that the black hole rotates. A new study published in Nature has given us more rotational evidence.

September 20, 2023September 20, 2023 by Evan Gough

Gluttonous Black Holes Eat Faster Than Thought. Does That Explain Quasars?

At the heart of large galaxies like our Milky Way, there resides a supermassive black hole (SMBH.) These behemoths draw stars, gas, and dust toward them with their irresistible gravitational pull. When they consume this material, there’s a bright flare of energy, the brightest of which are quasars.

While astrophysicists think that SMBHs eat too slowly to cause a particular type of quasar, new research suggests otherwise.

September 15, 2023September 15, 2023 by Evan Gough

Strong Evidence that Supermassive Black Holes Affect Their Host Galaxy’s Chemistry

This is a composite image of the spiral galaxy Messier 77 (NGC 1068), as observed by ALMA and the Hubble Space Telescope. Red and blue are different chemicals. Red are cyanide radicals concentrated mostly in the center and a large-scale ring-shaped gas structure, but also along the bipolar jets extending from the center towards the northeast (upper left) and southwest (lower right). Blue is carbon monoxide isotopes which avoid the central region. Image Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, T. Nakajima et al.

Supermassive Black Holes (SMBHs) are impossible to ignore. They can be billions of times more massive than the Sun, and when they’re actively consuming stars and gas, they become luminous active galactic nuclei (AGN.) A galaxy’s center is a busy place, with the activity centred on the SMBH.

New research provides strong evidence that while going about their business, SMBHs alter their host galaxy’s chemistry.

September 10, 2023September 10, 2023 by Brian Koberlein

The Closest Black Holes to Earth are Probably Hidden in This Nearby Star Cluster

The Hyades cluster, which is the closest star cluster to Earth. Credit: NASA, ESA, and STScI

In the constellation Taurus, there is a cluster of a few hundred stars known as the Hyades. The cluster is just 150 light-years away, and it could be harboring a stellar-mass black hole.