Since the 1970s, astronomers have observed that supermassive black holes (SMBHs) reside at the centers of most massive galaxies. In some cases, these black holes accelerate gas and dust from their poles, forming relativistic jets that can extend for thousands of light-years. Using the NASA/ESA Hubble Space Telescope, a team of astronomers observed the jet emanating from the center of M87, the supermassive galaxy located 53.5 million light-years away. To their surprise, the team observed nova erupting along the jet’s trajectory, twice as many as they observed in M87 itself.
Continue reading “Jets From Supermassive Black Holes Create New Stars Along Their Trajectory”Finally! Astronomers Find the Missing Link Between Stellar and Supermassive Black Holes
While black holes are known as the most destructive objects in the universe, their evolution is largely shrouded in mystery. This is because while astronomers are familiar with supermassive black holes that exist at the center of galaxies like our own and black holes whose masses are less than 100 times the size of our Sun, the notion of intermediate-mass black holes (IMBHs) have largely eluded discovery. However, this might change with the recent discovery of a black hole candidate that could exist within the globular cluster, Omega Centauri, and holds the potential to be the “missing link” in scientists better understanding black hole evolution.
Continue reading “Finally! Astronomers Find the Missing Link Between Stellar and Supermassive Black Holes”Galaxies Regulate their Own Growth so they Don’t Run Out of Star Forming Gas
Look at most spiral or barred spiral galaxies and you will see multiple regions where stars are forming. These star forming regions are comprised of mostly hydrogen gas with a few other elements for good measure. The first galaxies in the Universe had huge supplies of this star forming gas. Left unchecked they could have burned through the gas quickly, generating enormous amounts of star formation. Life fast though and die young for such an energetic burst of star formation would soon fizzle out leaving behind dead and dying stars. In some way it seems, galaxies seem to regulate their star formation thanks to supermassive black holes at their centre.
Continue reading “Galaxies Regulate their Own Growth so they Don’t Run Out of Star Forming Gas”A Supermassive Black Hole with a Case of the Hiccups
Can binary black holes, two black holes orbiting each other, influence their respective behaviors? This is what a recent study published in Science Advances hopes to address as a team of more than two dozen international researchers led by the Massachusetts Institute of Technology (MIT) investigated how a smaller black hole orbiting a supermassive black hole could alter the outbursts of the energy being emitted by the latter, essentially giving it “hiccups”. This study holds the potential to help astronomers better understand the behavior of binary black holes while producing new methods in finding more binary black holes throughout the cosmos.
Continue reading “A Supermassive Black Hole with a Case of the Hiccups”The Brightest Object Ever Seen in the Universe
It’s an exciting time in astronomy today, where records are being broken and reset regularly. We are barely two months into 2024, and already new records have been set for the farthest black hole yet observed, the brightest supernova, and the highest-energy gamma rays from our Sun. Most recently, an international team of astronomers using the ESO’s Very Large Telescope in Chile reportedly saw the brightest object ever observed in the Universe: a quasar (J0529-4351) located about 12 billion light years away that has the fastest-growing supermassive black hole (SMBH) at its center.
Continue reading “The Brightest Object Ever Seen in the Universe”The Event Horizon Telescope Zooms in on a Black Hole's Jet
Although supermassive black holes are common throughout the Universe, we don’t have many direct images of them. The problem is that while they can have a mass of millions or billions of stars, even the nearest supermassive black holes have tiny apparent sizes. The only direct images we have are those of M87* and Sag A*, and it took a virtual telescope the size of Earth to capture them. But we are still in the early days of the Event Horizon Telescope (EHT), and improvements are being made to the virtual telescope all the time. Which means we are starting to look at more supermassive black holes.
Continue reading “The Event Horizon Telescope Zooms in on a Black Hole's Jet”Sometimes Compact Galaxies Hide Their Black Holes
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.
Continue reading “Sometimes Compact Galaxies Hide Their Black Holes”A Black Hole Switched On in the Blink of an Eye
In 2019, a team of astronomers led by Dr. Samantha Oates of the University of Birmingham discovered one of the most powerful transients ever seen – where astronomical objects change their brightness over a short period. Oates and her colleagues found this object, known as J221951-484240 (or J221951), using the Ultra-Violet and Optical Telescope (UVOT) on NASA’s Neil Gehrels Swift Observatory while searching for the source of a gravitational wave (GW) that was thought to be caused by two massive objects merging in our galaxy.
Multiple follow-up observations were made using the UVOT and Swift’s other instruments – the Burst Alert Telescope (BAT) and X-Ray Telescope (XRT), the Hubble Space Telescope, the South African Large Telescope (SALT), the Wide-field Infrared Survey Explorer (WISE), the ESO’s Very Large Telescope (VLT), the Australia Telescope Compact Array (ATCA), and more. The combined observations and spectra revealed that the source was a supermassive black hole (SMBH) in a distant galaxy that mysteriously “switched on,” becoming one of the most dramatic bursts of brightness ever seen with a black hole.
Continue reading “A Black Hole Switched On in the Blink of an Eye”Pulsars Could Help Map the Black Hole at the Center of the Milky Way
The Theory of General Relativity (GR), proposed by Einstein over a century ago, remains one of the most well-known scientific postulates of all time. This theory, which explains how spacetime curvature is altered in the presence of massive objects, remains the cornerstone of our most widely-accepted cosmological models. This should come as no surprise since GR has been verified nine ways from Sunday and under the most extreme conditions imaginable. In particular, scientists have mounted several observation campaigns to test GR using Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.
Last year, the Event Horizon Telescope (EHT) – an international consortium of astronomers and observatories – announced they had taken the first images of Sag A*, which came just two years after the release of the first-ever images of an SMBH (M87). In 2014, the European members of the EHT launched another initiative known as BlackHoleCam to gain a better understanding of SMBHs using a combination of radio imaging, pulsar observations, astrometry, and GR. In a recent paper, the BHC initiative described how they tested GR by observing pulsars orbiting Sgr A*.
Continue reading “Pulsars Could Help Map the Black Hole at the Center of the Milky Way”Gaze at a Nearby Actively Feeding Supermassive Black Hole
Astronomers recently shared a new image captured by the Hubble Space Telescope of the galaxy NGC 4395. This relatively diffuse and dim dwarf galaxy is located just 14 million light-years from Earth.
NGC 4395 has several oddities, and this new image zooms in on the galaxy’s central region to highlight just one of those quirks. NGC 4395 is different from other dwarf galaxies because it contains an actively feeding supermassive black hole at its center.
But this black hole is considered one of the lowest mass supermassive holes ever detected, an oxymoron if there ever was one.
Continue reading “Gaze at a Nearby Actively Feeding Supermassive Black Hole”