Space and astronomy news
In the beginning, the Universe was all primordial gas. Somehow, some of it was swept up into supermassive black holes (SMBHs), the gargantuan singularities that reside at the heart of galaxies. The details of how that happened and how SMBHs accumulate mass are some of astrophysics’ biggest questions.
Continue reading “Black Holes Dominate Large Regions of Space, But They’re Mysterious”
When the James Webb Space Telescope was launched at the end of 2021, we expected stunning images and illuminating scientific results. So far, the powerful space telescope has lived up to our expectations. The JWST has shown us things about the early Universe we never anticipated.
Some of those results are forcing a rewrite of astronomy textbooks.
Continue reading “The JWST is Re-Writing Astronomy Textbooks”
Dyson Spheres have been a tantalising digression in the hunt for alien intelligence. Just recently seven stars have been identified as potential candidates with most of their radiation given off in the infrared wavelengths. Potentially this is the signature of heat from a matrix of spacecraft around the star but alas, a new paper has another slightly less exciting explanation; dust obscured galaxies.
Continue reading “There’s Another, More Boring Explanation for those Dyson Sphere Candidate Stars”
It’s difficult to actually visualise a universe that is changing. Things tend to happen at snails pace albeit with the odd exception. Take the formation of galaxies growing in the early universe. Their immense gravitational field would suck in dust and gas from the local vicinity creating vast collections of stars. In the very centre of these young galaxies, supermassive blackholes would reside turning the galaxy into powerful quasars. A recent survey by the James Webb Space Telescope (JWST) reveals that black holes can create a powerful solar wind that can remove gas from galaxies faster than they can form into stars, shutting off the creation of new stars.
Continue reading “Black Holes Can Halt Star Formation in Massive Galaxies”
Within almost every galaxy there is a supermassive black hole. This by itself implies some kind of formative connection between the two. We have also observed how gas and dust within a galaxy can drive the growth of galactic black holes, and how the dynamics of black holes can both drive star formation or hinder it depending on how active a black hole is. But one area where astronomers still have little information is how galaxies and their black holes interacted in the early Universe. Did black holes drive the formation of galaxies, or did early galaxies fuel the growth of black holes? A recent study suggests the two evolved hand in hand.
Continue reading “Even Early Galaxies Grew Hand-in-Hand With Their Supermassive 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”
For decades the most distant objects we could see were quasars. We now know they are powerful active black holes. Active galactic nuclei so distant that they resemble star-like points of light. It tells us that supermassive black holes in the early Universe can be powerful monsters that drive the evolution of their galaxies. We had thought most early supermassive black holes went through such an active phase, but a new study suggests most supermassive black holes don’t.
Continue reading “The Early Universe Should Be Awash in Active Galaxies, but JWST Isn't Finding Them”
After almost seventy years of study, astronomers are still fascinated by active galactic nuclei (AGN), otherwise known as quasi-stellar objects (or “quasars.”) These are the result of supermassive black holes (SMBHs) at the center of massive galaxies, which cause gas and dust to fall in around them and form accretion disks. The material in these disks is accelerated to close to the speed of light, causing it to release tremendous amounts of radiation in the visible, radio, infrared, ultraviolet, gamma-ray, and X-ray wavelengths. In fact, quasars are so bright that they temporarily outshine every star in their host galaxy’s disk combined.
The brightest quasar observed to date, 100,000 billion times as luminous as our Sun, is known as SMSS J114447.77-430859.3 (J1144). This AGN is hosted by a galaxy located roughly 9.6 billion light years from Earth between the constellations Centaurus and Hydra. Using data from the eROSITA All Sky Survey and other space telescopes, an international team of astronomers conducted the first X-ray observations of J1144. This data allowed the team to investigate prevailing theories about AGNs that could provide new insight into the inner workings of quasars and how they affect their host galaxies.
Continue reading “eROSITA Sees Changes in the Most Powerful Quasar”
Did humanity miss the party? Are SETI, the Drake Equation, and the Fermi Paradox all just artifacts of our ignorance about Advanced Life in the Universe? And if we are wrong, how would we know?
A new study focusing on black holes and their powerful effect on star formation suggests that we, as advanced life, might be relics from a bygone age in the Universe.
Continue reading “Advanced Life Should Have Already Peaked Billions of Years Ago”
In the 1970s, astronomers discovered that the persistent radio source at the center of our galaxy was a supermassive black hole (SMBH). Today, this gravitational behemoth is known as Sagittarius A* and has a mass roughly 4 million times that of the Sun. Since then, surveys have shown that SMBHs reside at the center of most massive galaxies and play a vital role in star formation and galactic evolution. In addition, the way these black holes consume gas and dust causes their respective galaxies to emit a tremendous amount of radiation from their Galactic Centers.
These are what astronomers refer to as Active Galactic Nuclei (AGN), or quasars, which can become so bright that they temporarily outshine all the stars in their disks. In fact, AGNs are the most powerful compact steady sources of energy in the Universe, which is why astronomers are always trying to get a closer look at them. For instance, a new study led by the University of California, Santa Cruz (UCSC) indicates that scientists have substantially underestimated the amount of energy emitted by AGN by not recognizing the extent to which their light is dimmed by dust.
Continue reading “Dust is Hiding how Powerful Quasars Really are”