Tag

Black Holes

All articles tagged with #black holes

space4 hours ago•105 min saved

Nearby ravenous black hole mirrors early-universe feeding frenzy

Astronomers observe a supermassive black hole at the center of SDSS J110546.07+145202.4 (about 1.8 billion light-years away) in a rapid accretion phase, launching jets and causing a roughly 20-fold increase in radio brightness over about eight years. The behavior resembles the vigorous feeding seen in the early universe, providing a nearby laboratory to study extreme accretion physics and jet production. The finding, published in The Astrophysical Journal (May), suggests such rapidly changing radio galaxies could help fill gaps in our understanding of early galaxy growth, with future SKA surveys expected to identify more transients.

via Space|

#accretion #black-holes #early-universe

science12 hours ago•3 min saved

Some Black Holes May Be Born From Earlier Black Hole Mergers

A new analysis of 155 binary black-hole mergers detected by LIGO/Virgo/KAGRA finds about 14% could be second-generation black holes formed from prior mergers, suggesting hierarchical mergers occur in dense stellar environments and can create unusually massive BHs in the 40+ solar-mass range, challenging simple stellar-collapse narratives and raising questions about their true origins.

via Gizmodo|

#black-holes #gravitational-waves #hierarchical-mergers

space2 days ago•119 min saved

Euclid finds two ancient quasars, each shining with a trillion suns

The European Space Agency's Euclid space telescope has spotted 31 newly identified quasars dating to the universe's first 770 million years, including the two oldest known at redshifts 7.77 and 7.69, each radiating about a trillion suns. The discoveries, published in Astronomy & Astrophysics, double the number of quasars known from that era and shed light on how supermassive black holes formed so rapidly after the Big Bang. Euclid's wide-field survey will uncover hundreds more, helping create the largest 3D map of the universe and revealing how early galaxies and black holes evolved.

via Live Science|

#black-holes #early-universe #euclid-telescope

astronomy4 days ago•11 min saved

Second-Generation Black Holes: Gravitational Waves Hint at Hierarchical Mergers

Analyses of GWTC-4.0 from multiple groups converge on a high-mass subpopulation of merging black holes consistent with hierarchical mergers, where at least one black hole is the remnant of a prior merger. Second-generation black holes should be roughly twice as massive as first-generation ones, with spins near 0.7 and random orientations; a transition around 40–45 solar masses marks the shift from low-spin to higher-spin populations. These results, obtained with diverse population models focusing on effective spins, bolster the case that dense environments produce recycled black holes and have implications for the mass gap and black-hole growth, with sharper insights expected as detectors improve.

via American Physical Society|

#astronomy #black-holes #gravitational-waves

science4 days ago•121 min saved

Direct-wave signal near a black hole horizon opens a new window on gravity

Researchers analyzed a very strong gravitational-wave event (GW250114) detected by LIGO on Jan. 14, 2025 and found evidence of a “direct wave” produced from near the horizon of the newly formed black hole. The signal, matching theoretical predictions, could allow astronomers to study the region just outside the event horizon using gravitational waves, potentially testing general relativity and informing ideas about quantum gravity and the black hole information paradox. However, the claim rests on a single observation, so further detections are needed to confirm this as a universal feature of black hole mergers.

via Live Science|

#black-holes #event-horizon #gravitational-waves

science7 days ago•7 min saved

Lab Light Reveals Direct Hawking Backreaction in Black-Hole Analog

Physicists used ultrafast laser pulses in a patterned optical fiber to create a black-hole analog that emits Hawking radiation and, for the first time, observed backreaction: a tiny energy shift in the initiating pulse caused by the radiation. The study suggests a direct, biquadratic interaction mechanism, helping explain how Hawking radiation could arise in gravity, though real black holes remain unobservable. If the same mechanism appears in other analogs, it could inform the black hole information paradox.

via ScienceAlert|

#analog-experiments #backreaction #black-holes

science8 days ago•14 min saved

JWST’s Early Universe Puzzles Fuel Fresh Theories

JWST observations of the infant universe reveal unexpectedly large black holes and bright, diverse galaxies, prompting competing theories from large seed black holes and super-Eddington growth to direct-collapse scenarios and naked black holes; researchers are refining models with new simulations and MIRI data, as they work to determine which explanations best fit the early cosmos and the process of reionization.

via Quanta Magazine|

#black-holes #cosmology #early-galaxies

space-and-spaceflight9 days ago•17 min saved

Gravastar Idea: A Dark-Energy ‘Mini-Universe’ Inside a Black Hole Mimic

Physicists propose gravastars—ultra-compact stars with a thin shell of ordinary matter and an interior powered by dark energy—that externally resemble black holes but lack singularities or event horizons. A new model shows how such objects could form from gravitational collapse and, in the process, trigger a Big Bang–like expansion inside a self-contained mini-universe. The scenario hinges on ideal, finely tuned conditions and does not replace black holes as the default outcome of collapse.

via Gizmodo|

#black-holes #dark-energy #general-relativity

science10 days ago•15 min saved

Direct waves from the loudest GW reveal a black hole’s horizon spin and gravity

The January 14, 2025 gravitational-wave event GW250114 was the loudest yet and contained a previously unread signal, the direct wave, emitted from just outside the remnant black hole’s horizon. By decoding this signal, researchers measured the horizon’s rotation frequency and surface gravity, finding results that match Kerr black-hole predictions and enabling horizon-focused tests of general relativity. This marks a new era of direct horizon metrology in gravitational-wave astronomy as detector sensitivity improves.

via Space Daily|

#black-holes #event-horizon #gravitational-waves

space11 days ago•5 min saved

Star Collapse May Forge a Mini-Universe: Gravastars as Black Hole Alternatives

A new study proposes gravastars—ultra-compact objects formed when collapsing stars create a miniature universe inside, with dark-energy interiors that halt collapse and mimic black holes without horizons or singularities—offering a GR-consistent alternative to black holes. Yet the mechanism requires fine-tuning, questions of stability remain, and it’s unclear how such objects could be distinguished observationally; formation remains a key open problem.

via Universe Today|

#black-holes #but-we-only-need-five-ensure-only-five-so-remove-extra #cosmology

space14 days ago•97 min saved

Loudest Gravitational-Wave Burst Maps Black Hole Event Horizon

Researchers analyzing GW250114—the loudest binary black hole merger detected by LIGO, Virgo, and KAGRA—identified a new component called direct waves and used it to probe the remnant black hole's horizon, measuring its rotation frequency and surface gravity; the work, published in Nature, could enable future tests of general relativity and deepen our understanding of what happens at a black hole's edge.

via Space|

#black-holes #event-horizon #gravitational-waves

space16 days ago•8 min saved

Euclid’s Milky Way Preview Boosts Roman’s Galactic Bulge Survey

ESA’s Euclid captured a Milky Way core snapshot to precede NASA’s Roman Space Telescope’s deep Galactic Bulge survey. By adding Euclid’s one-day preview to Roman’s planned observations, scientists will extend the survey window, improve Milky Way mapping, and enhance the detection of microlensing events that can reveal exoplanets and wandering stellar-mass black holes.

via NASA (.gov)|

#black-holes #euclid #microlensing

science16 days ago•22 min saved

Direct-wave signal exposes horizon physics in GW250114

Researchers report observational evidence of a direct-wave component in GW250114 from a binary-black-hole merger. The direct wave oscillates near twice the remnant horizon’s rotation rate and damps according to surface gravity, imprinting frame-dragging from the Kerr black hole and matching theoretical predictions. This new channel enables direct probing of near-horizon physics in strong gravity.

via Nature|

#black-holes #frame-dragging #gravitational-waves

space20 days ago•96 min saved

Echo mapping hints dark matter clusters around supermassive black holes

Astronomers used reverberation (echo) mapping to probe gas around supermassive black holes in 14 galaxies, finding in five cases that the enclosed mass increases with distance from the SMBH beyond what visible matter can explain. The results hint at dark matter clustering around SMBHs like Sagittarius A* and M87, offering a new method to study dark matter environments, though the findings are preliminary and not conclusive.

via Space|

#black-holes #dark-matter #echo-mapping

space22 days ago•97 min saved

Black holes' delayed radio burps decoded

Scientists reveal that the delayed radio bursts from tidal disruption events (stars torn apart by supermassive black holes) occur when the black hole’s feeding rate is either too fast or too slow, ejecting gas that slams into surrounding material to produce radio emissions. By combining decades of VLA radio data with optical/UV and X-ray follow-ups for 31 well-tracked TDEs (from a larger sample of 91 candidates), researchers mapped the actual gas consumption over time and linked late flares to two feeding-rate extremes. A helium emission signature in early spectra also signals a delayed disk formation. The study suggests a two-to-six-year window after discovery to detect these late emissions and shows the mechanism works across vastly different black-hole masses, helping scientists optimize telescope time.

via Space|

#astronomy #black-holes #radio-astronomy