Using a model that places a light black hole in an envelope of dense gas, they get results that match much of what we see in little red dots.
Category: cosmology
These ancient quasars shouldn’t exist so soon after the Big Bang
Scientists have found the oldest quasars ever seen, revealing giant black holes blazing across the universe when it was only 670 million years old. Astronomers have uncovered 31 of the oldest known quasars, including the two earliest ever detected, shining from a time when the universe was only about 670 million years old. Powered by supermassive black holes billions of times the Sun’s mass, these incredibly bright objects challenge scientists’ understanding of how such enormous black holes formed so quickly after the Big Bang.
Quasars rank among the brightest and most powerful objects in the universe. They are fueled by supermassive black holes that consume surrounding material at the centers of galaxies, producing so much energy that they can be seen across billions of light years.
Now, an international team of researchers has identified 31 of the oldest quasars ever discovered, including the two earliest known examples. These extraordinary objects were already shining with the light of roughly a trillion suns when the universe was only about 670 million years old. The discovery, published in Astronomy & Astrophysics, offers an unprecedented glimpse into one of the earliest chapters of cosmic history.
A Map to a Long-Sought Quantum Simulator
The Sachdev-Ye-Kitaev (SYK) model describes information scrambling in black holes and an unusual metallic phase in high-temperature superconductors. Despite those and other far-reaching applications, realizing the model in the lab has been extremely challenging because the particle interactions required are intricate and long-ranged. Now Charles Creffield at the Complutense University of Madrid and his colleagues have detailed how this model could be simulated in existing cold-atom setups [1]. Their strategy provides a practical path to exploring quantum phenomena that are currently confined to theory.
Rather than engineer the requisite particle interactions from the outset, the team started with a much simpler setup emulating the Hubbard model, which is used to understand how electrons moving in a lattice give rise to superconductivity and other phenomena. Ultracold atoms are placed in a one-dimensional optical lattice, where they hop between lattice sites and mutually repel each other when occupying the same site. The lattice is then periodically shaken to make the rate of hopping oscillate in time. This modulation suppresses the atoms’ ordinary motion and generates effective interactions between all the atoms at once, closely resembling the particle behavior of the SYK model.
Using detailed numerical simulations, the researchers went on to show that their Hubbard-based system reproduces several key features of the SYK model, including its characteristic chaotic dynamics and fast spreading of quantum information. The team emphasizes that its approach could be enacted straightforwardly using currently available cold-atom technologies. Such an implementation would offer a controlled, versatile platform for simulating the SYK model and possibly for probing the uncertain physics of quantum chaos and quantum gravity.
Black hole jet may be stirring gas cloud containing early ‘red potato’ galaxy
A black hole may be stirring a “pot” of gas containing a neighboring galaxy in the early universe, according to a new study published in Astronomy & Astrophysics that used observations from NASA’s Chandra X-ray Observatory. The galaxy slowly being “cooked” is named MQN01 J004131.9–493704, but astronomers have nicknamed it the “red potato” because of its appearance in images from NASA’s James Webb Space Telescope.
The red potato galaxy is located about 11.7 billion light-years from Earth at an intersection where gigantic web-like structures of galaxies and gas meet. Astronomers targeted this area with Webb because they knew it contained one of the heaviest concentrations of galaxies and growing supermassive black holes yet identified in the early universe.
Jellyfish nebula may be the scene of two stars going supernova
The star that formed the Jellyfish nebula may have had a partner star that exploded 100,000 years earlier, according to international researchers, who say that this may be the first known discovery of a binary star system in which both stars have gone supernova.
The Jellyfish nebula, known as IC 443, is the remnant of a star exploding in a supernova and leaving behind an expanding cloud of debris. IC 443 is located in the Gemini constellation, approximately 6,000 light-years from Earth, and researchers have now discovered that it occupies the same physical environment as another supernova remnant called G189.6+3.3. The findings are published in the journal Nature Communications.
Supernova remnants are expanding clouds of debris left behind after supernovae (stellar explosions). While hundreds of such remnants are known in our galaxy, identifying relationships between them is difficult, particularly in crowded regions of the Milky Way. IC 443, a remnant in the constellation Gemini approximately 6,000 light-years from Earth, sits close to other astronomical structures and within a complex cloud of gas and dust, making its surrounding region difficult to study.
New radio-burst method helps locate universe’s missing ordinary matter
Stars and galaxies make up much of the universe’s ordinary, observable matter. But for decades, scientists have wrestled with a cosmic conflict: There should be much more.
Physicists have good estimates of how much matter was present in the early universe. Shortly after the Big Bang, roughly 83% of all matter in the universe was composed of invisible dark matter, with ordinary matter making up the rest. And yet, these estimates exceed the amount of ordinary matter seen in stars and galaxies today. Where, then, did all the missing ordinary matter go?
Now MIT scientists, as part of the CHIME/FRB Collaboration, are using far-off radio signals to reveal missing matter in the vast space between galaxies. The team has developed a new method to search out missing matter by combining locations of galaxies with detections of fast radio bursts.
One idea, two cosmic mysteries—linking Little Red Dots and globular clusters
A new study led by astronomers at The University of Texas at Austin proposes a theory that could solve two astronomical riddles at once: the nature of Little Red Dots and the origin of globular clusters. Rather than representing distinct objects, the study suggests that one may instead be the ancestor of the other: Little Red Dots are, in fact, an early form of globular clusters. The findings are published in The Astrophysical Journal Letters.
First detected by the James Webb Space Telescope (JWST) in 2022, Little Red Dots are mysterious objects that appear 600 million years after the Big Bang, only to seemingly disappear 1.5 billion years later. They are compact, luminous and shine with a distinctive combination of red and ultraviolet light.
One theory is that Little Red Dots represent supermassive black holes, enshrouded in dense clouds of gas, that pull young stars into dramatic deaths. This scenario explains many of the objects’ signature properties. However, other scenarios could also fit.
Astronomers spot an extremely rare galaxy mega-merger
Scale in the universe is hard to understand from a purely human perspective. Many times, the math just doesn’t sit well with our brains, which evolved to capture and process data about the world around us rather than grok the complexities of stellar dynamics and galaxy mergers. But every once in a while, astronomers find something that, if we can wrap our heads around the numbers, gives a sense of just how big the universe is.
That is precisely what a new paper, available on the arXiv preprint server from a group of astronomers led by Z.L. Wen of the Chinese Academy of Sciences, hopes to do when it describes a merger of not one, not two, but six supermassive galaxies and the active dynamics they are subject to.
Admittedly, this paper isn’t the one that originally found the cluster. That was done back in 2018 by several all-sky surveys, including the Two Micron All Sky Survey, WISE and SuperCOSMOS. But it was the first to identify that the cluster contained a group of six merging galaxies at its heart. That tidbit was hidden away in Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys data.