astronomy
Mysterious dashes revealed in Milky Way’s center
Hundreds of horizontal filaments point toward our central supermassive black hole
MeerKAT image of the galactic center with color-coded position angles of all filaments.
« Mysterious dashes revealed in Milky Way’s center
- New radio telescope images reveal hundreds of filaments along the galactic plane, each measuring 5 to 10 light-years in length
- These structures likely originated a few million years ago when outflow from our supermassive black hole interacted with surrounding materials
- Researcher: ‘I was actually stunned when I saw these’
Newswise — EVANSTON, Ill. — An international team of astrophysicists has discovered something wholly new, hidden in the center of the Milky Way galaxy.
In the early 1980s, Northwestern University’s Farhad Yusef-Zadeh discovered gigantic, one-dimensional filaments dangling vertically near Sagittarius A*, our galaxy’s central supermassive black hole. Now, Yusef-Zadeh and his collaborators have discovered a new population of filaments — but these threads are much shorter and lie horizontally or radially, spreading out like spokes on a wheel from the black hole.
Although the two populations of filaments share several similarities, Yusef-Zadeh assumes they have different origins. While the vertical filaments sweep through the galaxy, towering up to 150 light-years high, the horizontal filaments look more like the dots and dashes of Morse code, punctuating only one side of Sagittarius A*.
The study will be published on Friday (June 2) in The Astrophysical Journal Letters.
“It was a surprise to suddenly find a new population of structures that seem to be pointing in the direction of the black hole,” Yusef-Zadeh said. “I was actually stunned when I saw these. We had to do a lot of work to establish that we weren’t fooling ourselves. And we found that these filaments are not random but appear to be tied to the outflow of our black hole. By studying them, we could learn more about the black hole’s spin and accretion disk orientation. It is satisfying when one finds order in a middle of a chaotic field of the nucleus of our galaxy.”
An expert in radio astronomy, Yusef-Zadeh is a professor of physics and astronomy at Northwestern’s Weinberg College of Arts and Sciences and member of CIERA.
Decades in the making
The new discovery may come as a surprise, but Yusef-Zadeh is no stranger to uncovering mysteries at the center of our galaxy, located 25,000 light-years from Earth. The latest study builds on four decades of his research. After first discovering the vertical filaments in 1984 with Mark Morris and Don Chance, Yusef-Zadeh along with Ian Heywood and their collaborators later uncovered two gigantic radio-emitting bubbles near Sagittarius A*. Then, in a series of publications in 2022, Yusef-Zadeh (in collaborations with Heywood, Richard Arent and Mark Wardle) revealed nearly 1,000 vertical filaments, which appeared in pairs and clusters, often stacked equally spaced or side by side like strings on a harp.
Yusef-Zadeh credits the flood of new discoveries to enhanced radio astronomy technology, particularly the South African Radio Astronomy Observatory’s (SARAO) MeerKAT telescope. To pinpoint the filaments, Yusef-Zadeh’s team used a technique to remove the background and smooth the noise from MeerKAT images in order to isolate the filaments from surrounding structures.
“The new MeerKAT observations have been a game changer,” he said. “The advancement of technology and dedicated observing time have given us new information. It’s really a technical achievement from radio astronomers.”
Horizontal vs. vertical
After studying the vertical filaments for decades, Yusef-Zadeh was shocked to uncover their horizontal counterparts, which he estimates are about 6 million years old. “We have always been thinking about vertical filaments and their origin,” he said. “I’m used to them being vertical. I never considered there might be others along the plane.”
While both populations comprise one-dimensional filaments that can be viewed with radio waves and appear to be tied to activities in the galactic center, the similarities end there.
The vertical filaments are perpendicular to the galactic plane; the horizontal filaments are parallel to the plane but point radially toward the center of the galaxy where the black hole lies. The vertical filaments are magnetic and relativistic; the horizontal filaments appear to emit thermal radiation. The vertical filaments encompass particles moving at speeds near the speed of light; the horizontal filaments appear to accelerate thermal material in a molecular cloud. There are several hundred vertical filaments and just a few hundred horizontal filaments. And the vertical filaments, which measure up to 150 light-years high, far surpass the size of the horizontal filaments, which measure just 5 to 10 light-years in length. The vertical filaments also adorn space around the nucleus of the galaxy; the horizontal filaments appear to spread out to only one side, pointing toward the black hole.
“One of the most important implications of radial outflow that we have detected is the orientation of the accretion disk and the jet-driven outflow from Sagittarius A* along the galactic plane,” Yusef-Zadeh said.
‘Our work is never complete’
The new discovery is filled with unknowns, and Yusef-Zadeh’s work to unravel its mysteries has just begun. For now, he can only consider a plausible explanation about the new population’s mechanisms and origins.
“We think they must have originated with some kind of outflow from an activity that happened a few million years ago,” Yusef-Zadeh said. “It seems to be the result of an interaction of that outflowing material with objects near it. Our work is never complete. We always need to make new observations and continually challenge our ideas and tighten up our analysis.”
The study, “The population of the galactic center filaments: Position angle distribution reveal a degree-scale collimated outflow from Sgr A* along the galactic plane,” was supported by NASA (award number 80GSFC21M0002). The SARAO is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.
Source: Northwestern University
Author
Discover more from Daily News
Subscribe to get the latest posts sent to your email.
Science
Jets from powerful black holes can point astronomers toward where − and where not − to look for life in the universe
David Garofalo, Kennesaw State University
One of the most powerful objects in the universe is a radio quasar – a spinning black hole spraying out highly energetic particles. Come too close to one, and you’d get sucked in by its gravitational pull, or burn up from the intense heat surrounding it. But ironically, studying black holes and their jets can give researchers insight into where potentially habitable worlds might be in the universe.
As an astrophysicist, I’ve spent two decades modeling how black holes spin, how that creates jets, and how they affect the environment of space around them.
What are black holes?
Black holes are massive, astrophysical objects that use gravity to pull surrounding objects into them. Active black holes have a pancake-shaped structure around them called an accretion disk, which contains hot, electrically charged gas.
The plasma that makes up the accretion disk comes from farther out in the galaxy. When two galaxies collide and merge, gas is funneled into the central region of that merger. Some of that gas ends up getting close to the newly merged black hole and forms the accretion disk.
There is one supermassive black hole at the heart of every massive galaxy.
Black holes and their disks can rotate, and when they do, they drag space and time with them – a concept that’s mind-boggling and very hard to grasp conceptually. But black holes are important to study because they produce enormous amounts of energy that can influence galaxies.
How energetic a black hole is depends on different factors, such as the mass of the black hole, whether it rotates rapidly, and whether lots of material falls onto it. Mergers fuel the most energetic black holes, but not all black holes are fed by gas from a merger. In spiral galaxies, for example, less gas tends to fall into the center, and the central black hole tends to have less energy.
One of the ways they generate energy is through what scientists call “jets” of highly energetic particles. A black hole can pull in magnetic fields and energetic particles surrounding it, and then as the black hole rotates, the magnetic fields twist into a jet that sprays out highly energetic particles.
Magnetic fields twist around the black hole as it rotates to store energy – kind of like when you pull and twist a rubber band. When you release the rubber band, it snaps forward. Similarly, the magnetic fields release their energy by producing these jets.
These jets can speed up or suppress the formation of stars in a galaxy, depending on how the energy is released into the black hole’s host galaxy.
Rotating black holes
Some black holes, however, rotate in a different direction than the accretion disk around them. This phenomenon is called counterrotation, and some studies my colleagues and I have conducted suggest that it’s a key feature governing the behavior of one of the most powerful kinds of objects in the universe: the radio quasar.
Radio quasars are the subclass of black holes that produce the most powerful energy and jets.
You can imagine the black hole as a rotating sphere, and the accretion disk as a disk with a hole in the center. The black hole sits in that center hole and rotates one way, while the accretion disk rotates the other way.
This counterrotation forces the black hole to spin down and eventually up again in the other direction, called corotation. Imagine a basketball that spins one way, but you keep tapping it to rotate in the other. The tapping will spin the basketball down. If you continue to tap in the opposite direction, it will eventually spin up and rotate in the other direction. The accretion disk does the same thing.
Since the jets tap into the black hole’s rotational energy, they are powerful only when the black hole is spinning rapidly. The change from counterrotation to corotation takes at least 100 million years. Many initially counterrotating black holes take billions of years to become rapidly spinning corotating black holes.
So, these black holes would produce powerful jets both early and later in their lifetimes, with an interlude in the middle where the jets are either weak or nonexistent.
When the black hole spins in counterrotation with respect to its accretion disk, that motion produces strong jets that push molecules in the surrounding gas close together, which leads to the formation of stars.
But later, in corotation, the jet tilts. This tilt makes it so that the jet impinges directly on the gas, heating it up and inhibiting star formation. In addition to that, the jet also sprays X-rays across the galaxy. Cosmic X-rays are bad for life because they can harm organic tissue.
For life to thrive, it most likely needs a planet with a habitable ecosystem, and clouds of hot gas saturated with X-rays don’t contain such planets. So, astronomers can instead look for galaxies without a tilted jet coming from its black hole. This idea is key to understanding where intelligence could potentially have emerged and matured in the universe.
Black holes as a guide
By early 2022, I had built a black hole model to use as a guide. It could point out environments with the right kind of black holes to produce the greatest number of planets without spraying them with X-rays. Life in such environments could emerge to its full potential. https://www.youtube.com/embed/b7mTVX9IE0s?wmode=transparent&start=0 Looking at black holes and their role in star formation could help scientists predict when and where life was most likely to form.
Where are such conditions present? The answer is low-density environments where galaxies had merged about 11 billion years ago.
These environments had black holes whose powerful jets enhanced the rate of star formation, but they never experienced a bout of tilted jets in corotation. In short, my model suggested that theoretically, the most advanced extraterrestrial civilization would have likely emerged on the cosmic scene far away and billions of years ago.
David Garofalo, Professor of Physics, Kennesaw State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Discover more from Daily News
Subscribe to get the latest posts sent to your email.
The Knowledge
The Mystical Glow of the Night Sky: Exploring Zodiacal Light
Zodiacal light, seen before sunrise, is sunlight scattering off interplanetary dust in the zodiacal cloud. It represents a cosmic connection, best viewed in dark, clear locations during specific times of the year.
Have you ever looked up at the night sky and noticed a faint glow, gracefully extending from the horizon in a triangular shape? This enchanting phenomenon is known as zodiacal light, often referred to as “false dawn” when it’s visible just before sunrise. While it may seem like a mere trick of the light, the zodiacal light holds a fascinating story about the universe surrounding our planet.
The Science Behind Zodiacal Light
Zodiacal light is the result of sunlight scattering off interplanetary dust, creating a delicate illumination in the night sky. This dust resides in a thick, pancake-shaped cloud known as the zodiacal cloud, which orbits in the ecliptic plane of our Solar System. Ranging from 10 to 300 micrometers in size, these tiny particles have masses that can span from one nanogram to several micrograms. Together, they contribute to what we see as a soft glow, complementing the natural light of a moonless night.
Interestingly, zodiacal light can be seen most effectively in dark locations, far away from the interference of city lights or moonlight. When conditions are perfect—a clear night with minimal light pollution—this soft glow stretches from the direction of the Sun, gracefully illuminating the darker parts of the sky. It’s most prominent in the western sky during spring after sunset and in the eastern sky during autumn before dawn.
The Origins of Cosmic Dust
The source of the dust that creates zodiacal light has long been a subject of exploration and debate. Initially thought to originate from active comet tails or collisions among asteroids, recent research suggests that a significant portion of the dust comes from the gradual fragmentation of dormant comets, specifically those in the Jupiter-family category.
When comets break apart, they send tiny fragments scattering through space. As these particles eventually disintegrate further due to collisions and space weathering, they continue to replenish the zodiacal dust cloud. This dynamic relationship ensures that our view of zodiacal light is not just a fleeting moment, but a persistent feature of our cosmic environment.
Viewing Zodiacal Light: Tips and Tricks
To catch a glimpse of this celestial beauty, timing and location are crucial. For those in mid-latitude regions, the ideal times to observe zodiacal light are during the evenings in spring and mornings in autumn. Choose a spot far from city lights, under a clear and moonless sky. As twilight fades, lean back, breathe in the fresh evening air, and let your eyes adjust to the darkness.
The sight will often reveal a column of light that appears brighter near the horizon and tilts at an angle parallel to the ecliptic. Often mistaken for a glimpse of the Milky Way, zodiacal light offers a serene reminder of the intricate cosmos we inhabit.
The Connection to Gegenschein
Zodiacal light isn’t the only celestial phenomenon related to interplanetary dust. There’s also the gegenschein, or “counterglow,” which is a faint oval glow seen directly opposite the Sun. This unique aspect of zodiacal light and gegenschein adds depth to our understanding of celestial phenomena and invites us to ponder our place in the universe.
A Cosmic Invitation
Zodiacal light is not just a backdrop for the stars; it represents a beautiful, cosmic connection between our planet and the infinity beyond. It serves as a gentle reminder of the fleeting moments in nature—moments that encourage us to pause, look up, and marvel at the intricate dance of light and dust that swirls around us.
So next time you find yourself under a dark sky, take a moment to seek out this enchanting glow. The zodiacal light is waiting, inviting you to experience the magic of our universe. Happy stargazing!
For more information visit these links:
Wikipedia: https://en.wikipedia.org/wiki/Zodiacal_light
Earth-Sky: https://earthsky.org/astronomy-essentials/zodiacal-light-false-dusk-how-to-see-explanation/
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Discover more from Daily News
Subscribe to get the latest posts sent to your email.
astronomy
A Celestial Spectacle: Witness the Rare Planetary Parade on February 28
On February 28, 2025, a rare planetary parade will showcase all seven planets aligning in the night sky. This remarkable event won’t occur again until 2040, making it unmissable.
Planetary Parade
Astronomy enthusiasts and casual stargazers alike have something extraordinary to look forward to at the end of February. For one brief moment, on the evening of February 28, 2025, all seven planets—Mars, Jupiter, Uranus, Venus, Neptune, Mercury, and Saturn—will align in the night sky, creating a captivating planetary parade. This remarkable event marks the last time such an alignment will be visible until 2040, making it an occasion not to be missed.
What to Expect
The planetary parade will unfold shortly after sunset, with each planet showcasing its brilliance against the backdrop of the evening sky. While most of these celestial bodies will shine brighter than even the brightest stars, Uranus and Neptune will likely require binoculars or a telescope for a better view.
Currently, six of the planets are already aligned, but stargazers will have to wait until February 28 for Mercury to make its debut just above the horizon. Dr. Christopher Barnes, a senior lecturer at the University of Derby, explains the visibility details: “Mars will appear in the east, Jupiter and Uranus in the southeast, and Venus, Neptune, and Saturn in the west.”
Viewing Tips
For those wishing to experience this cosmic event, the best time to observe will be just after sunset when the stars begin to appear. Dr. Barnes suggests that even people in urban areas, where light pollution is often an issue, will be able to see most of the planets. However, seeking a location away from city lights will enhance the viewing experience.
The Benefits of Stargazing
Beyond the thrilling visual spectacle, taking time to gaze upon the stars and planets offers numerous benefits for one’s mental and emotional well-being. Dr. Barnes points out that stargazing encourages mindfulness, allowing individuals to detach from the stresses of daily life. “Engaging with the night sky fosters a sense of peace, restoration, and perspective,” he says.
Future Events
After February 28, the next opportunity to see a planetary alignment of five or more planets will occur in late October 2028 and again in February 2034. However, another seven-planet alignment will not be witnessed for another 15 years, making this February a particularly special occasion.
To cater to those unable to view the parade due to unfavorable weather or light pollution, several observatories will provide live streams of the event. This means everyone can partake in this astral celebration from the comfort of their homes.
As we approach February 28, it’s time to mark your calendars for this rare planetary parade. Whether you grab your telescope, plan a trip to a dark-sky location, or tune in to a live stream, don’t miss your chance to witness this extraordinary alignment of the planets, a spectacle that will be remembered long after it fades from view. Prepare to look up and enjoy the wonders of our solar system!
Resources:
Who doesn’t love a parade, especially a planet parade? How and when to see up to 7 planets
Planetary Parade will soon be visible in the evening sky
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Discover more from Daily News
Subscribe to get the latest posts sent to your email.
-
Urbanism2 years agoSignal Hill, California: A Historic Enclave Surrounded by Long Beach
-
News2 years agoDiana Gregory Talks to us about Diana Gregory’s Outreach Services
-
Senior Pickleball Report2 years agoThe Absolute Most Comfortable Pickleball Shoe I’ve Ever Worn!
-
STM Blog2 years agoWorld Naked Gardening Day: Celebrating Body Acceptance and Nature
-
Senior Pickleball Report2 years agoACE PICKLEBALL CLUB TO DEBUT THEIR HIGHLY ANTICIPATED INDOOR PICKLEBALL FRANCHISES IN THE US, IN EARLY 2023
-
Travel2 years agoUnique Experiences at the CitizenM
-
Automotive2 years ago2023 Nissan Sentra pricing starts at $19,950
-
Senior Pickleball Report2 years ago“THE PEOPLE’S CHOICE AWARDS OF PICKLEBALL” – VOTING OPEN