Mystery Resolved: Black Hole Feeding and Feedback at the Center of an Active Galaxy

Fig. 1
An illustration depicting the distribution of interstellar medium in the active galactic nucleus based on the results of this observation.
Illustration Credit: ©ALMA (ESO/NAOJ/NRAO), T. Izumi et al.

An international research team led by Takuma Izumi, an assistant professor at the National Astronomical Observatory of Japan, has observed in high resolution (approximately 1 light year) the active galactic nucleus of the Circinus Galaxy - one of the closest major galaxies to the Milky Way. The observation was made possible by the Atacama Large Millimeter/Submillimeter Array (ALMA) astronomical observatory in Chile.

This breakthrough marks the world's first quantitative measurement at this scale of gas flows and their structures of a nearby supermassive black hole in all phase gases, including plasma, atomic, and molecular. Such high resolution allowed the team to team to capture the accretion flow heading towards the supermassive black hole, revealing that this accretion flow is generated by a physical mechanism known as 'gravitational instability.' Furthermore, the team also found that a significant portion of this accretion flow does not contribute to the growth of the black hole. Instead, most of the gas is expelled from the vicinity of the black hole as atomic or molecular outflows, and returns to the gas disk to participate again into an accretion flow towards the black hole, much like how water gets recycled in a water fountain. These findings represent a crucial advancement towards a greater understanding of the growth mechanisms of supermassive black holes.

Jurassic worlds might be easier to spot than modern Earth

Modeling by Cornell astronomers finds that telescopes could more easily detect an exoplanet with higher levels of atmospheric oxygen than modern Earth, as existed during the dinosaur age.
Illustration Credit: Rebecca Payne/Carl Sagan Institute

Might a tyrannosaur roam on Trappist-1e, a protoceratops on Proxima Centauri b, or a quetzalcoatlus on Kepler 1047c?

Things may not have ended well for dinosaurs on Earth, but Cornell astronomers say the “light fingerprint” of the conditions that enabled them to emerge here – including abundant atmospheric oxygen – provides a crucial missing piece in our search for signs of life on planets orbiting other stars.

Modeling by Cornell astronomers finds that telescopes could more easily detect an exoplanet with higher levels of atmospheric oxygen than modern Earth, as existed during the dinosaur age.

Their analysis of the most recent 540 million years of Earth’s evolution, known as the Phanerozoic Eon, finds that telescopes could better detect potential chemical signatures of life in the atmosphere of an Earth-like exoplanet more closely resembling the age the dinosaurs inhabited than the one we know today.

Two key biosignature pairs – oxygen and methane, and ozone and methane – appeared stronger in models of Earth roughly 100 million to 300 million years ago, when oxygen levels were significantly higher. The models simulated the transmission spectra, or light fingerprint, generated by an atmosphere that absorbs some colors of starlight and lets others filter through, information scientists use to determine the atmosphere’s composition.

Giant planets cast a deadly pall

Artist's depiction of a star system that is crowded with giant planets.
Illustration Credit: NASA/Dana Berry

Giant gas planets can be agents of chaos, ensuring nothing lives on their Earth-like neighbors around other stars. New studies show, in some planetary systems, the giants tend to kick smaller planets out of orbit and wreak havoc on their climates. 

Jupiter, by far the biggest planet in our solar system, plays an important protective role. Its enormous gravitational field deflects comets and asteroids that might otherwise hit Earth, helping create a stable environment for life. However, giant planets elsewhere in the universe do not necessarily protect life on their smaller, rocky planet neighbors. 

A new Astronomical Journal paper details how the pull of massive planets in a nearby star system are likely to toss their Earth-like neighbors out of the “habitable zone.” This zone is defined as the range of distances from a star that is warm enough for liquid water to exist on a planet’s surface, making life possible.

Unlike most other known solar systems, the four giant planets in HD 141399 are farther from their star. This makes it a good model for comparison with our solar system where Jupiter and Saturn are also relatively far from the sun.  

“It’s as if they have four Jupiters acting like wrecking balls, throwing everything out of whack,” said Stephen Kane, UC Riverside astrophysicist and author of the journal paper. 

Sheffield astronomers help to confirm heaviest elements in the Universe are formed in kilonovae

The Gamma-Ray Burst (GRB) 230307A and its associated kilonova explosion.
Image Credit: NASA, ESA, CSA, STScI, A. Levan (Radboud University and University of Warwick)

Astrophysicists are one step closer to understanding how the heaviest chemical elements are created in the universe, thanks to a camera designed and built at the University of Sheffield.

Scientists from the Astrophysics Group at the University of Sheffield observed the merger of two dense neutron stars, known as a kilonova, in a spiral galaxy a billion light years away

The discovery of the kilonova, only the second one to be observed, was made possible thanks to observations with the University of Sheffield’s camera ULTRACAM mounted on the New Technology Telescope at the European Southern Observatory in Chile

Kilonovae are important because their explosions are believed to form the heaviest elements in the periodic table, including most of the gold, platinum and uranium found on Earth

Astrophysicists are one step closer to understanding how the heaviest chemical elements are created in the universe, thanks to a camera designed and built at the University of Sheffield.

Venus had Earth-like plate tectonics billions of years ago

Photo Credit: NASA/JPL

A new study found that Venus, a scorching wasteland of a planet according to scientists, may have once had tectonic plate movements similar to those believed to have occurred on early Earth, a new study found. The finding sets up tantalizing scenarios regarding the possibility of early life on Venus, its evolutionary past and the history of the solar system.

Writing in Nature Astronomy, a team of scientists led by Brown University researchers describes using atmospheric data from Venus and computer modeling to show that the composition of the planet’s current atmosphere and surface pressure would only have been possible as a result of an early form of plate tectonics, a process critical to life that involves multiple continental plates pushing, pulling and sliding beneath one another.

On Earth, this process intensified over billions of years, forming new continents and mountains, and leading to chemical reactions that stabilized the planet’s surface temperature, resulting in an environment more conducive to the development of life.

Deep learning speeds up galactic calculations

A more efficient simulation.
During a supernova simulation, (left) shows the prediction by a current simulation method. (right) shows the prediction by 3D-MIM, which looks close enough to the that of the current leading method, but it takes far less time to execute, saving time, energy and costs for computing time.
Image Credit: ©2023 Hirashima et al.
(CC-BY-ND)

Supernovae, exploding stars, play a critical role in the formation and evolution of galaxies. However, key aspects of them are notoriously difficult to simulate accurately in reasonably short amounts of time. For the first time, a team of researchers, including those from The University of Tokyo, apply deep learning to the problem of supernova simulation. Their approach can speed up the simulation of supernovae, and therefore of galaxy formation and evolution as well. These simulations include the evolution of the chemistry which led to life.

When you hear about deep learning, you might think of the latest app that sprung up this week to do something clever with images or generate humanlike text. Deep learning might be responsible for some behind-the-scenes aspects of such things, but it’s also used extensively in different fields of research. Recently, a team at a tech event called a hackathon applied deep learning to weather forecasting. It proved quite effective, and this got doctoral student Keiya Hirashima from the University of Tokyo’s Department of Astronomy thinking.

Astronomers detect most distant fast radio burst to date

This artist’s impression (not to scale) illustrates the path of the fast radio burst FRB 20220610A, from the distant galaxy where it originated all the way to Earth, in one of the Milky Way’s spiral arms. The source galaxy of FRB 20220610A, pinned down thanks to ESO’s Very Large Telescope, appears to be located within a small group of interacting galaxies. It’s so far away its light took eight billion years to reach us, making FRB 20220610A the most distant fast radio burst found to date. 
Full Size Image
Credit: ESO/M. Kornmesser

An international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This 'fast radio burst' (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our Sun’s total emission over 30 years.

The discovery of the burst, named FRB 20220610A, was made in June last year by the ASKAP radio telescope in Australia and it smashed the team’s previous distance record by 50 percent.

“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published today in Science. “Then we used [ESO’s VLT] in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies.”

New patterns in Sun’s layers could help scientists solve solar mystery

In this image, the fine-structure of the quiet Sun is observed at its surface or photosphere.
Image Credit: NSF/AURA/NSO

Astronomers are one step closer to understanding one of the most enduring solar mysteries, having captured unprecedented data from the Sun’s magnetic field.

New research from an international team may explain one of the biggest conundrums in astrophysics – why the outermost layer of the Sun’s atmosphere is hotter than the surface

Groundbreaking data collected from the world's most powerful solar telescopes shows a snake-like pattern in the Sun’s magnetic fields that could contribute to the heating of the Sun’s outermost atmosphere

The project, which includes scientists across a wide range of institutions on both sides of the Atlantic Ocean, has opened new avenues in solar physics

Astronomers are one step closer to understanding one of the most enduring solar mysteries, having captured unprecedented data from the Sun’s magnetic field.

A new lens” into the Universe’s most energetic particles

An example of a cosmic-ray extensive air shower recorded by the Subaru Telescope. The highlighted tracks, which are mostly aligned in similar directions, show the shower particles induced from a high-energy cosmic ray. 
Image Credit: National Astronomical Observatory of Japan, Hyper Suprime-Cam (HSC) Collaboration

Showers in bathrooms bring us comfort; showers from space bring astrophysicists joy. Osaka Metropolitan University scientists have observed, with their novel method, cosmic-ray extensive air showers with unprecedented precision, opening the door to new insights into the Universe’s most energetic particles.

When a high energy cosmic ray collides with the Earth's atmosphere, it generates an enormous number of particles known as an extensive air shower. A research team led by Associate Professor Toshihiro Fujii from the Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics at Osaka Metropolitan University, along with graduate student Fraser Bradfield, has discovered that the prime-focus wide field camera mounted on the Subaru Telescope, situated atop the Mauna Kea volcano in Hawaii, can capture these extensive air showers with extremely high resolution.

“Starquakes” could explain mystery signals

Earthquake map. Data on earthquakes was taken from Japan’s Kanto region (including Tokyo and Narita) and Izumo in the Chugoku region (north of Hiroshima). Black dots represent the epicenters of earthquakes recorded between May 6, 2010, and December 31, 2012.
Image Credit: ©2023 T. Totani & Y. Tsuzuki

Fast radio bursts, or FRBs, are an astronomical mystery, with their exact cause and origins still unconfirmed. These intense bursts of radio energy are invisible to the human eye, but show up brightly on radio telescopes. Previous studies have noted broad similarities between the energy distribution of repeat FRBs, and that of earthquakes and solar flares. However, new research at the University of Tokyo has looked at the time and energy of FRBs and found distinct differences between FRBs and solar flares, but several notable similarities between FRBs and earthquakes. This supports the theory that FRBs are caused by “starquakes” on the surface of neutron stars. This discovery could help us better understand earthquakes, the behavior of high-density matter and aspects of nuclear physics.

The vastness of space holds many mysteries. While some people dream of boldly going where no one has gone before, there is a lot we can learn from the comfort of Earth. Thanks to technological advances, we can explore the surface of Mars, marvel at Saturn’s rings and pick up mysterious signals from deep space. Fast radio bursts are hugely powerful, bright bursts of energy which are visible on radio waves. First discovered in 2007, these bursts can travel billions of light years but typically last mere thousandths of a second. It has been estimated that as many as 10,000 FRBs may happen every day if we could observe the whole sky. While the sources of most bursts detected so far appear to emit a one-off event, there are about 50 FRB sources which emit bursts repeatedly.

Researchers capture first-ever afterglow of huge planetary collision in outer space

Image shows a visualization of the huge, glowing planetary body produced by a planetary collision. In the foreground, fragments of ice and rock fly away from the collision and will later cross in between Earth and the host star which is seen in the background of the image.
Illustration Credit: Mark Garlick

A chance social media post by an eagle-eyed amateur astronomer sparked the discovery of an explosive collision between two giant planets, which crashed into each other in a distant space system 1,800 light years away from planet Earth.

The study, published today in Nature, reports the sighting of two ice giant exoplanets colliding around a sun-like star, creating a blaze of light and plumes of dust. Its findings show the bright heat afterglow and resulting dust cloud, which moved in front of the parent star dimming it over time.

The international team of astronomers was formed after an enthusiast viewed the light curve of the star and noticed something strange. It showed the system doubled in brightness at infrared wavelengths some three years before the star started to fade in visible light.

Co-lead author Dr Matthew Kenworthy, from Leiden University, said: “To be honest, this observation was a complete surprise to me. When we originally shared the visible light curve of this star with other astronomers, we started watching it with a network of other telescopes.

Stellar fountain of youth with turbulent formation history in the center of our galaxy

A multi-wavelength view of the surroundings of the supermassive black hole SgrA * (yellow X). The stars are red, the dust is blue. Many of the young stars in the IRS13 star cluster are covered by dust or covered by the bright stars.
Credits: Florian Peißker / University of Cologne

An international team led by Dr Florian Peißker at the University of Cologne’s Institute of Astrophysics has analyzed in detail a young star cluster in the immediate vicinity of the super massive black hole Sagittarius A* (Sgr A*) in the center of our galaxy and showed that it is significantly younger than expected. This cluster, known as IRS13, was discovered more than twenty years ago, but only now has it been possible to determine the cluster members in detail by combining a wide variety of data – taken with various telescopes over a period of several decades. The stars are a few 100,000 years old and therefore extraordinarily young for stellar conditions. By comparison, our sun is about 5 billion years old. Due to the high-energy radiation as well as the tidal forces of the galaxy, it should in fact not be possible for such a large number of young stars to be in the direct vicinity of the super massive black hole. The study was conducted under the title ‘The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. I. Detection of a Rich Population of Dusty Objects in the IRS13 Cluster’ and has now appeared in The Astrophysical Journal.

Astronomers Discover First Step Toward Planet Formation

An image of the radio wave strength at a wavelength of 1.3 mm of the disk around the star DG Taurus, observed with ALMA. Unlike older protostellar disks, ring-like structures have not yet formed, suggesting that the disk is at the stage just before planet formation.
Image Credit: ALMA (ESO/NAOJ/NRAO), S. Ohashi et al.

An international research team led by Project Assistant Professor Satoshi Ohashi of the National Astronomical Observatory of Japan (NAOJ) has conducted high-resolution and multi-wavelength observations of a protoplanetary disk around a relatively young protostar, DG Taurus (DG Tau), using ALMA* to study the structure of the disk and the size and amount of dust, the material for planets. Associate Professor Okuzumi from Tokyo Institute of Technology (Tokyo Tech) participated in this research as a team member. As a result, the team succeeded in capturing the conditions on the eve of planet formation, as the disk was smooth with no signature of planets. They also found that the dust had grown significantly in the outer part of the disk and that the dust concentration was higher than normal in the inner part of the disk. With these results, the first step in the process of planet formation has been revealed.

Study suggests large mound structures on Kuiper belt object Arrokoth may have common origin

The large mound structures that dominate one of the lobes of the Kuiper belt object Arrokoth are similar enough to suggest a common origin, according to a new study led by Southwest Research Institute (SwRI) Planetary Scientist and Associate Vice President Dr. Alan Stern.
Graphic Credit: Courtesy of SwRI

A new study led by Southwest Research Institute (SwRI) Planetary Scientist and Associate Vice President Dr. Alan Stern posits that the large, approximately 5-kilometer-long mounds that dominate the appearance of the larger lobe of the pristine Kuiper Belt object Arrokoth are similar enough to suggest a common origin. The SwRI study suggests that these “building blocks” could guide further work on planetesimal formational models. Stern presented these findings this week at the American Astronomical Society’s 55th Annual Division for Planetary Sciences (DPS) meeting in San Antonio. These results are now also published in the peer-reviewed Planetary Science Journal.

NASA’s New Horizons spacecraft made a close flyby of Arrokoth in 2019. From those data, Stern and his coauthors identified 12 mounds on Arrokoth’s larger lobe, Wenu, which are almost the same shape, size, color and reflectivity. They also tentatively identified three more mounds on the object’s smaller lobe, Weeyo..

Two-decade monitoring of M87 unveils a precessing jet connecting to a spinning black hole

Schematic representation of the tilted accretion disk model. The black hole spin axis is assumed to align vertically. The jet direction stands almost perpendicular to the disk plane. The misalignment between the black hole spin axis and disk rotation axis triggers the precession of disk and jet.
Illustration Credit: Yuzhu Cui et al. (2023), Intouchable Lab@Openverse and Zhejiang Lab.

In a tale of cosmic patience spanning more than two decades, it has been discovered that the nearby radio galaxy M87, located 55 million light-years from the Earth and harboring a black hole 6.5 billion times more massive than the Sun, exhibits an oscillating jet. This investigation found the jet swinging up and down with an amplitude of about 10 degrees.

The international collaboration team consisting of researchers from 45 institutions around the world, including Dr. Satoko Sawada-Satoh of Osaka Metropolitan University’s Graduate School of Science, analyzed data observed from 2000 to 2022. They unveiled a recurring 11-year cycle in the precessing motion of the jet base, as predicted by Einstein’s general relativity. This work successfully linked the dynamics of the jet with the central supermassive black hole, offering evidence for the existence of M87’s black hole spin.

Extreme Weight Loss: Star Sheds Unexpected Amounts of Mass Just Before Going Supernova

Artist's conception of pre-explosion mass loss by the progenitor star of SN 2023ixf. In the year prior to going supernova the red supergiant star now known as SN 2023ixf shed an unexpected amount of mass equivalent to the mass of the Sun. This artist's conception illustrates what the final stages of mass loss might have looked like before the star exploded. 
Illustration Credit: Melissa Weiss/CfA

A newly discovered nearby supernova whose star ejected up to a full solar mass of material in the year prior to its explosion is challenging the standard theory of stellar evolution. The new observations are giving astronomers insight into what happens in the final year prior to a star’s death and explosion.

SN 2023ixf is a new Type II supernova discovered in May 2023 by amateur astronomer Kōichi Itagaki of Yamagata, Japan shortly after its progenitor, or origin star, exploded. Located about 20 million light-years away in the Pinwheel Galaxy, SN 2023ixf's proximity to Earth, the supernova's extreme brightness, and its young age make it a treasure trove of observable data for scientists studying the death of massive stars in supernova explosions.

Type II or core-collapse supernovae occur when red supergiant stars at least eight times, and up to about 25 times the mass of the Sun, collapse under their own weight and explode. While SN 2023ixf fits the Type II description, follow-up multi-wavelength observations led by astronomers at the Center for Astrophysics | Harvard & Smithsonian (CfA), and using a wide range of CfA's telescopes, have revealed new and unexpected behavior.

Pass the salt: This space rock holds clues as to how Earth got its water

Asteroid Itokawa as seen by the Hayabusa spacecraft. The peanut-shaped S-type asteroid measures approximately 1,100 feet in diameter and completes one rotation every 12 hours.
Photo Credit: JAXA

The discovery of tiny salt grains in an asteroid sample brought to Earth by the Japanese Hayabusa spacecraft provides strong evidence that liquid water may be more common in the solar system's largest asteroid population than previously thought.

Sodium chloride, better known as table salt, isn't exactly the type of mineral that captures the imagination of scientists. However, a smattering of tiny salt crystals discovered in a sample from an asteroid has researchers at the University of Arizona Lunar and Planetary Laboratory excited, because these crystals can only have formed in the presence of liquid water.

Even more intriguing, according to the research team, is the fact that the sample comes from an S-type asteroid, a category known to mostly lack hydrated, or water-bearing, minerals. The discovery strongly suggests that a large number of asteroids hurtling through the solar system may not be as dry as previously thought. The finding, published in Nature Astronomy, gives renewed push to the hypothesis that most, if not all, water on Earth may have arrived by way of asteroids during the planet's tumultuous infancy.

Zega and lead study author Shaofan Che, a postdoctoral fellow at the Lunar and Planetary Laboratory, performed a detailed analysis of samples collected from asteroid Itokawa in 2005 by the Japanese Hayabusa mission and brought to Earth in 2010. 

New Keck Observatory Instrument Sets Its Sights on Turtle Nebula

The Keck and Subaru observatories atop Maunakea summit in Hawaiʻi.
Photo Credit: Tracey Parmley Nuki

A new instrument for studying a web of filaments that connects galaxies across the universe has captured its first image, a milestone known in astronomy as "first light." The Keck Cosmic Reionization Mapper (KCRM) at the W.M. Keck Observatory atop Maunakea summit in Hawaiʻi, will provide detailed maps of gas around dying stars and other cosmic objects, and it will map the so-called cosmic web that links and feeds galaxies. The instrument was recently installed next to its partner, the Keck Cosmic Web Imager (KCWI), which began operations in 2017.

"I envisioned this instrument as a two-armed imaging spectrograph back in 2007, based on our Palomar Cosmic Web Imager, but it was a long road to get the funding, so we split the instrument into two halves," says Christopher Martin, the instrument's principal investigator and a professor of physics at Caltech. "KCWI was already doing phenomenal science with one arm tied behind its back, so now it's off to the races. It is fitting that our first-light image shows two ‘arms' of the turtle nebula. We would not have made it without the work of our fantastic instrument team and support from Caltech, the Keck Observatory, the National Science Foundation, and a generous anonymous donor."

Elusive planets play “hide and seek” with CHEOPS

Artist's impression of CHEOPS.
Illustration Credit: ESA / ATG medialab

With the help of the CHEOPS space telescope an international team of European astronomers managed to clearly identify the existence of four new exoplanets. The four mini-Neptunes are smaller and cooler, and more difficult to find than the so-called Hot Jupiter exoplanets which have been found in abundance. Two of the four resulting papers are led by researchers from the University of Bern and the University of Geneva who are also members of the National Centre of Competence in Research (NCCR) PlanetS.

CHEOPS is a joint mission by the European Space Agency (ESA) and Switzerland, under the leadership of the University of Bern in collaboration with the University of Geneva. Since its launch in December 2019, the extremely precise measurements of CHEOPS have contributed to several key discoveries in the field of exoplanets.

NCCR PlanetS members Dr. Solène Ulmer-Moll of the Universities of Bern and Geneva, and Dr. Hugh Osborn of the University of Bern, exploited the unique synergy of CHEOPS and the NASA satellite TESS, in order to detect a series of elusive exoplanets. The planets, called TOI 5678 b and HIP 9618 c respectively, are the size of Neptune or slightly smaller with 4.9 and 3.4 Earth radii. The respective papers have just been published in the journals Astronomy & Astrophysics and Monthly Notices of the Royal Astronomical Society. Publishing in the same journals, two other members of the international team, Amy Tuson from the University of Cambridge (UK) and Dr. Zoltán Garai from the "ELTE Gothard Astrophysical Observatory (Hungary), used the same technique to identify two similar planets in other systems.

‘Hot Jupiters’ may not be orbiting alone

Indiana University assistant professor of astronomy Songhu Wang.
Photo Credit: James Brosher, Indiana University

Research led by an Indiana University astronomer challenges longstanding beliefs about the isolation of “hot Jupiters” and proposes a new mechanism for understanding the exoplanets’ evolution.

While our Jupiter is far away from the sun, hot Jupiters are gas giant planets that closely orbit stars outside our solar system for an orbital period of less than 10 days. Previous studies suggested they rarely have any nearby companion planets, leading scientists to believe that hot Jupiters formed and evolved through a violent process that expelled other planets from the area as they moved closer to their host stars. The research team’s findings reveal that hot Jupiters do not always orbit alone.

“Our research shows that at least a fraction of hot Jupiters cannot form through a violent process,” said Songhu Wang, assistant professor of astronomy in the College of Arts and Sciences. “This is a significant contribution to advance our understanding of hot Jupiter formation, which can help us learn more about our own solar system.”