IAU Commission X1

NASA’s Hubble Identifies One of Darkest Known Galaxies

Using the NASA/ESA Hubble Space Telescope, astronomers have identified an exceptionally faint galaxy, known as Candidate Dark Galaxy-2 (CDG-2), that appears to be nearly invisible except for a few surrounding globular star clusters. By combining Hubble’s sharp imaging with data from ESA’s Euclid and the Subaru Telescope, researchers confirmed the presence of a diffuse glow indicating an underlying galaxy that is overwhelmingly dominated by dark matter, making it one of the darkest known galaxies ever discovered. This finding, enabled by advanced statistical techniques to detect faint structures, offers new insights into the hidden population of dark matter-rich galaxies in the nearby universe.

An International Team of Astronomers Led by Umass Amherst May Have Just Found One of the Missing Links in Galaxy Evolution

An international team of astronomers has uncovered a previously unknown population of dusty, star-forming galaxies that existed just about one billion years after the Big Bang. These ancient galaxies, identified through a combination of ALMA’s submillimeter data and James Webb Space Telescope observations, may represent a “missing link” in the evolutionary sequence between ultrabright early galaxies and much older quiescent ones, challenging current models of how galaxies formed and evolved in the early universe.

Silent Giants, Hidden Fuel: ALMA Reveals Surprising Diversity of Dust and Gas in Quiescent Galaxies

New observations with the ALMA have revealed that massive quiescent galaxies, long thought to be “red and dead” with little dust or gas, actually display a surprising diversity in their reservoirs of cold dust and molecular gas even billions of years after they stop forming stars. Some of these “silent giants” retain significant amounts of fuel for star formation, while others are nearly depleted, indicating that the processes governing the evolution of dust and gas after quenching can vary widely and are more complex than previously assumed. This challenges traditional models of how galaxies age and suggests new pathways for understanding the late stages of galaxy evolution.

Cosmic predators: How supermassive black holes slow star growth in nearby galaxies

A recent study led by astronomers at the University of Arizona shows that intense radiation from active supermassive black holes, especially when they appear as bright quasars, can suppress the formation of new stars not only in their own galaxies but also in neighboring ones across millions of light years. By analysing data from the James Webb Space Telescope, the team found that galaxies near a powerful quasar exhibit weaker indicators of recent star formation, suggesting that these “cosmic predators” influence galaxy growth on intergalactic scales and reshape our understanding of galaxy evolution.

James Webb Space Telescope finds an early‑universe galaxy collision no one expected

Using observations from the James Webb Space Telescope (JWST), astronomers have discovered evidence of a galaxy collision in the early universe that challenges current models of how structures formed shortly after the Big Bang. The interacting galaxies, seen when the universe was less than a billion years old, show features that suggest a surprisingly advanced dynamical state for such ancient systems. This unexpected encounter provides new insights into the complexity of early galaxy assembly and highlights JWST’s power to uncover the hidden processes shaping the young cosmos.

New Event Horizon Telescope Results Trace M87 Jet Back to Its Black Hole

Using enhanced 2021 observations from the global Event Horizon Telescope network, astronomers have traced the enormous jet emanating from the supermassive black hole at the center of the galaxy M87 back to its likely launch point near the black hole’s glowing ring of emission. By incorporating new telescope baselines, including the powerful ALMA array, the team bridged the gap between the black hole’s immediate surroundings and the large-scale jet, offering fresh clues about how such jets are powered and launched.

NASA Telescopes Spot Surprisingly Mature Cluster in Early Universe

NASA’s Chandra X-ray Observatory, in combination with the James Webb Space Telescope, observed one of the earliest known galaxy protoclusters, JADES-ID1, forming just about a billion years after the Big Bang. This massive structure—about 20 trillion times the mass of the Sun—challenges existing theories of how quickly the largest cosmic systems assembled and offers new insights into the early growth of galaxy clusters.

New Discovery Challenges Evolution of Galaxy Clusters

Using ALMA, astronomers have detected the earliest known hot intracluster gas in a forming galaxy cluster when the Universe was only ~1.4 billion years old, revealing a much hotter and more energetic environment than expected and challenging current models of cluster growth. This young cluster hosts numerous starburst galaxies and active supermassive black holes, offering new clues into how massive structures assemble and evolve in the early cosmos.

Young Galaxies Grow Up Fast

A new multi‑wavelength survey of 18 distant galaxies around 12.5 billion light‑years away reveals that young galaxies matured much more rapidly than expected, showing high levels of heavy elements and developed structures at an early cosmic epoch. These observations challenge traditional views of galaxy growth and offer fresh insight into how stars, gas, and supermassive black holes evolved in the first billion years after the Big Bang.

Hidden Giants of the Early Universe: NSF NRAO Telescopes Help Reveal Divergent Fates of the Most Massive Galaxies

Astronomers using ALMA and the NSF’s Very Large Array have uncovered that the most ultramassive galaxies just 1–2 billion years after the Big Bang follow divergent evolutionary paths: while most truly quenched their star formation early, some continue forming stars hidden by dust. These results show that powerful feedback and cold‑gas depletion play key roles in halting star birth in the Universe’s largest early galaxies.

Radio Black Hole Trio Lights Up in Rare Galaxy Merger

Astronomers have confirmed a rare system, J1218/1219+1035, where three galaxies in the process of merging each host a radio‑bright, actively accreting supermassive black hole, making it the first known triple radio AGN observed with synchronized jet activity. This discovery provides a unique laboratory to study how galaxy collisions fuel black hole growth and shape cosmic evolution.

Bright Blue Cosmic Outbursts Likely Caused by Large Black Holes Shredding Massive Companions

Analysis of the brightest luminous fast blue optical transient (LFBOT) yet observed shows that these mysterious cosmic flashes are likely caused by intermediate‑mass black holes tearing apart massive stellar companions, rather than by standard supernova explosions. This discovery clarifies the physical origin of these brief yet extremely energetic events and offers new insight into the variety of stellar catastrophes astronomers encounter across the universe.

NASA IXPE's Longest Observation to Date Solves Viral Black Hole Jets Mystery

An international team using NASA’s IXPE and Chandra X‑ray Observatory has identified the long‑sought origin of X‑rays in the powerful jet of the active galaxy 3C 84 in the Perseus Cluster, favoring a synchrotron self‑Compton mechanism over competing models. The results resolve a decades‑old mystery about how X‑ray jet emission arises in this iconic supermassive black hole system.

NASA's Chandra Finds Small Galaxies May Buck the Black Hole Trend

A new study using over two decades of Chandra X‑ray data finds that only about 30 % of dwarf galaxies likely host supermassive black holes, significantly lower than in massive galaxies, where more than 90 % show clear central black hole signatures. This challenges the assumption that most galaxies contain giant black holes and offers new insights into how supermassive black holes form and evolve across cosmic history.

Astronomers Discover Fastest-Evolving Radio Signals Ever Observed from Black Hole Tearing Apart Star

Astronomers have observed the first off-center tidal disruption event, a star torn apart by a black hole, producing double radio bursts and showing the fastest-evolving radio signals ever recorded.

NASA's Chandra Finds Black Hole With Tremendous Growth

Astronomers, using NASA’s Chandra X-ray Observatory, have found a supermassive black hole, RACS J0320-35, growing at one of the fastest rates ever observed—about 2.4 times the Eddington limit. This quasar, located 12.8 billion light-years away, will help scientists understand how early black holes formed, how they reach enormous masses so quickly, and how rapid growth may trigger high-speed particle jets.

Astronomers Catch Supermassive Black Hole in the Act of “Waking Up”

Using, NSF, VLBA and VLA, astronomers captured a supermassive black hole in the CHIPS 1911+4455 cluster just as it re-awakened from dormancy, launching its first plasma jets only ~1,000 years ago. This rare “infant” stage offers a unique opportunity to study how black holes begin influencing the evolution of their host galaxies.

Record-Breaking Cosmic Structure Discovered in Colossal Galaxy Cluster

Scientists have discovered an enormous galaxy cluster, PLCK G287.0+32.9, surrounded by the largest known cloud of high-energy particles—stretching over 20 million light-years. This record-breaking structure sheds new light on how turbulence and shock waves in galaxy clusters can sustain powerful radio emissions over billions of years.

NASA's Hubble, Chandra Spot Rare Type of Black Hole Eating a Star"

NASA’s Hubble and Chandra telescopes have identified a tantalizing candidate for an intermediate‑mass black hole, named NGC 6099 HLX‑1, located roughly 450 million light‑years away. The object appears to be tearing apart a passing star (a tidal disruption event), producing intense X-rays and optical light that signal the rare feeding behavior of this cosmic middle‑weight black hole.

NASA Webb 'Pierces' Bullet Cluster, Refines Its Mass"

A stunning new image of the Bullet Cluster, combining data from NASA’s Chandra X-ray Observatory and the James Webb Space Telescope, reveals a detailed view of the separation between hot gas, dark matter, and galaxies. This visualization offers new insights into the cluster’s mass distribution and strengthens constraints on the behavior of dark matter during cosmic collisions.
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NASA's Chandra Sees Surprisingly Strong Black Hole Jet at Cosmic "Noon"

A powerful jet from a distant black hole, observed with the Chandra X-ray Observatory and the VLA, offers a rare glimpse into the early Universe. Illuminated by the afterglow of the Big Bang, this jet dates back to “cosmic noon”, when galaxies and black holes were growing at their fastest.

NASA Telescopes Tune Into a Black Hole Prelude, Fugue

NASA has released three new sonifications that explore different stages of black hole evolution. These include WR 124, a massive star potentially collapsing into a black hole; SS 433, a binary system emitting X-rays; and Centaurus A, a galaxy with a supermassive black hole launching a jet across its span.

NASA's Hubble Pinpoints Roaming Massive Black Hole

Researchers have discovered a rare, wandering supermassive black hole devouring a star in a galaxy 600 million light-years away. Unlike typical tidal disruption events that occur at galactic centers, this event was observed 2,600 light-years from the galaxy's core, indicating the presence of a second, offset black hole.

Webb Maps Full Picture of How Phoenix Galaxy Cluster Forms

Researchers have resolved the mystery of the Phoenix Galaxy Cluster's high star formation rate by utilizing data from the James Webb Space Telescope and other observatories. They discovered that intermediary warm gas within cavities tracing the very hot gas reconciles the cooling and star-formation rates.

This Quasar May Have Helped Turn the Lights on for the Universe

The newly discovered quasar J1429+5447 in the early universe, with its rapid X-ray brightening, reveals a powerful jet pointed toward Earth. This rare finding provides key insights into reionization and the mysterious growth of supermassive black holes.

NASA’s Swift Studies Gas-Churning Monster Black Holes

Swift Observatory has discovered two supermassive black holes disrupting a gas cloud at the center of a distant galaxy, producing periodic flares as they orbit each other. The event is identified as the tidal disruption of a massive gas cloud, offering new insights into black hole interactions and galaxy evolution.

Celebrate NASA’s Chandra 25th Anniversary

NASA’s Chandra X-ray Observatory marks 25 years in space with the release of 25 stunning new images, showcasing its unparalleled view of the universe. From black holes to exploding stars, Chandra continues to revolutionize our understanding of the cosmos.