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"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All posts tagged under »BLACK HOLES«
Birth of a black hole?
A new kind of cosmic flash may reveal something never seen before: the birth of a black hole. When a massive star exhausts its fuel, it collapses under its own gravity and produces a black hole, an object so dense that not even light can escape its gravitational grip. According to a new analysis by […]
Gravity-less toy black hole solves cosmic puzzles
March 26, 2013
With a pull so strong not even light escapes, a black hole is defined by its gravity. But now a model that ignores gravity is proving surprisingly useful for pinning down how these cosmic giants work. Black holes are where big ideas in cosmology, such as gravity and quantum mechanics, collide. That makes them great […]
Charged Black Hole Remnants at the LHC
March 16, 2013
G.L. Alberghi, L. Bellagamba, X. Calmet, R. Casadio, O. Micu We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished […]
Ultrarelativistic Black Hole Formation
March 13, 2013
William E. East, Frans Pretorius We study the ultrarelativistic head-on collision of equal mass particles, modeled as self-gravitating fluid spheres, by numerically solving the coupled Einstein-hydrodynamic equations. We focus on cases well within the kinetic energy dominated regime, where between 88-92% (γ=8 to 12) of the initial net energy of the spacetime resides in the […]
A black-hole mass measurement …
January 31, 2013
… from molecular gas kinematics in NGC4526 Timothy A. Davis, Martin Bureau, Michele Cappellari, Marc Sarzi & Leo Blitz The masses of the supermassive black holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black holes may evolve together. The number of reliably measured black-hole […]
Black Hole Complementarity and the Harlow-Hayden Conjecture
January 22, 2013
Leonard Susskind Black hole complementarity, as originally formulated in the 1990′s by Preskill, ‘t Hooft, and myself is now being challenged by the Almheiri-Marolf-Polchinski-Sully firewall argument. The AMPS argument relies on an implicit assumption—the “proximity postulate—which says that the interior of a black hole must be constructed from degrees of freedom that are physically near […]
Multidimensional black holes get electric when flexed
December 17, 2012
Bending a black hole can juice it up. In extra dimensions, a black hole behaves like a fluid and a solid at the same time, and flexing the solid form may generate an electric field. Although these effects exist only in the theoretical realm, the underlying equations could help us puzzle out some of the […]
Common physics among black holes
December 13, 2012
A Universal Scaling for the Energetics of Relativistic Jets from Black Hole Systems R. S. Nemmen, M. Georganopoulos, S. Guiriec, E. T. Meyer, N. Gehrels, R. M. Sambruna Black holes generate collimated, relativistic jets, which have been observed in gamma-ray bursts (GRBs), microquasars, and at the center of some galaxies [active galactic nuclei (AGN)]. How […]
A Multi-Wavelength View of Radio Galaxy Hercules-A
November 29, 2012
Spectacular jets powered by the gravitational energy of a supermassive black hole in the core of the elliptical galaxy Hercules A illustrate the combined imaging power of two of astronomy’s cutting-edge tools, the Hubble Space Telescope’s Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New […]
Biggest Black Hole Blast Discovered
November 28, 2012
Astronomers using ESO’s Very Large Telescope (VLT) have discovered a quasar with the most energetic outflow ever seen, at least five times more powerful than any that have been observed to date. Quasars are extremely bright galactic centres powered by supermassive black holes. Many blast huge amounts of material out into their host galaxies, and […]
Thermodynamics of a Black Hole with Moon
November 13, 2012
Samuel E. Gralla, Alexandre Le Tiec For a rotating black hole perturbed by a particle on the “corotating” circular orbit (angular velocity equal to that of the event horizon), the black hole remains in equilibrium in the sense that the perturbed event horizon is a Killing horizon of the helical Killing field. The associated surface […]
NASA’s NuSTAR Spots Flare From Milky Way’s Black Hole
October 23, 2012
PASADENA, Calif. – NASA’s newest set of X-ray eyes in the sky, the Nuclear Spectroscopic Telescope Array (NuSTAR), has caught its first look at the giant black hole parked at the center of our galaxy. The observations show the typically mild-mannered black hole during the middle of a flare-up. “We got lucky to have captured […]
Ripping a hole in space and time
October 6, 2012
By Kenneth Macdonald In an unassuming laboratory at Heriot-Watt University in Edinburgh, they are ripping a hole in the fabric of space and time. Not too far away, they are working with information that can mean two things at once. They are two separate studies, but what they have in common is the interaction of […]
Heavy photons are too light to be behind dark matter
September 15, 2012
SADLY, dark matter is not made of light. That may sound obvious, but many physicists were hoping that photons – particles of light – could help us to piece together the nature of the mysterious stuff thought to make up 85 per cent of the universe’s matter. Instead, readings from Vitor Cardoso of the Technical […]
A Sky Chock-Full of Black Holes
August 29, 2012
Read more: NASA’s WISE Survey Uncovers Millions of Black Holes
Space-time ripples record black hole crashes
August 19, 2012
Did monster black holes pull the first galaxies together, or were they born inside those galaxies? It’s a long-standing mystery. Now a new analysis of the gravitational ripples from colliding black holes could reveal the answer by helping astronomers reconstruct a crash rather than just surveying its aftermath. Most large galaxies we see have supermassive black holes […]
Most distant black hole ‘heard’ munching star
August 3, 2012
by Kelly Oakes The wobbles in energy produced as a black hole consumes a star have been detected from further away than ever before. Because they are so regular, their discoverer likes to think of the wobbles as a kind of sound. “We are able to metaphorically hear a star being devoured by a supermassive […]
Flaring black holes may solve cosmic ray puzzle
July 30, 2012
WHERE do ultra high-energy cosmic rays come from? These charged particles zoom to Earth from outer space, but why is a mystery. Now a possible source – gamma-ray bursts, which seemed to have been ruled out – have received a new lease of life. Gamma-ray bursts are usually created by exploding stars, which produce neutrinos. […]
How Black Holes Shape the Galaxies, Stars and Planets around Them
July 17, 2012
The matter-eating beast at the center of the Milky Way may actually account for Earth’s existence and habitability Black holes, such as the four-million-solar-mass lurker at the center of our galaxy, are not simply consumers. They also radiate copious amounts of energy as they devour nearby matter. A black hole’s feeding habits can have a […]
Black Holes as Particle Detectors
June 18, 2012
Finding new particles usually requires high energies — that is why huge accelerators have been built, which can accelerate particles to almost the speed of light. But there are other creative ways of finding new particles: At the Vienna University of Technology, scientists presented a method to prove the existence of hypothetical “axions.” These axions […]
Cosmic climate change may have stunted black holes
June 10, 2012
A WARMING of the early universe caused by the greediest of black holes could have stunted the growth of the rest. Astronomical surveys suggest that supermassive black holes weighing a billion times more than the sun had formed before the universe was a billion years old. The seeds for these behemoths are thought to be […]
CID-42: Exceptional Properties
June 5, 2012
The galaxy at the center of this image contains an X-ray source, CID-42, with exceptional properties. After combining data from several telescopes — including NASA’s Chandra X-ray Observatory — researchers think that CID-42 contains a massive black hole being ejected from its host galaxy at several million miles per hour. The main panel is a […]
From black holes to strange metals
June 2, 2012
Hong Liu Ever since the end of the Stone Age, metals have fascinated humankind and have been vital in the development of civilization. More recently, physicists have been fascinated by a new class of “strange” metals, discovered two decades ago, whose exotic properties challenge fundamental notions of condensed-matter physics. In this Quick Study I describe […]
Black Hole Caught Red-Handed in a Stellar Homicide
May 2, 2012
This computer simulation shows a star being shredded by the gravity of a massive black hole. Some of the stellar debris falls into the black hole and some of it is ejected into space at high speeds. The areas in white are regions of highest density, with progressively redder colors corresponding to lower-density regions. The […]
Chandra Sees Remarkable Outburst From Old Black Hole
April 30, 2012
An extraordinary outburst produced by a black hole in a nearby galaxy has provided direct evidence for a population of old, volatile stellar black holes. The discovery, made by astronomers using NASA’s Chandra X-ray Observatory, provides new insight into the nature of a mysterious class of black holes that can produce as much energy in […]
Footprints of Higher-Dimensional Decaying Black Holes
April 12, 2012
Panagiota Kanti We review the current results for the emission of Hawking radiation by a higher-dimensional black hole during the Schwarzschild and the spin-down phases. We discuss particularly the role of the angular variation of the emitted radiation on the brane during the latter phase, the radiation spectra for gravitons in the bulk, and the […]
Is it possible to create a quantum electromagnetic “black hole” at the LHC?
April 7, 2012
Igor I. Smolyaninov As demonstrated by Chernodub, strong magnetic field forces vacuum to develop real condensates of electrically charged rho mesons, which form an anisotropic inhomogeneous superconducting state similar to Abrikosov vortex lattice. As far as electromagnetic field behaviour is concerned, this state of vacuum constitutes a hyperbolic metamaterial [1]. Here we demonstrate that spatial […]
Earth has little to fear from a black hole attack
March 30, 2012
Detectable seismic consequences of the interaction of a primordial black hole with Earth Yang Luo, Shravan Hanasoge, Jeroen Tromp, Frans Pretorius Galaxies observed today are likely to have evolved from density perturbations in the early universe. Perturbations that exceeded some critical threshold are conjectured to have undergone gravitational collapse to form primordial black holes (PBHs) at […]
Black holes and the LHC: A review
March 24, 2012
Seong Chan Park In low-scale gravity models, a particle collider with trans-Planckian collision energies can be an ideal place for producing black holes because a large amount of energy can be concentrated at the collision point, which can ultimately lead to black hole formation. In this article, the theoretical foundation for microscopic higher dimensional black […]
Discovery of an exotic galaxy, Speca
March 21, 2012
Speca – An Intriguing Look Into The Beginning Of A Black Hole Jet Its catalog number is NGC 3801, but its name is SPECA – a Spiral-host Episodic radio galaxy tracing Cluster Accretion. That’s certainly a mouthful of words for this unusual galaxy, but there’s a lot more going on here than just its name. […]
Search for microscopic black holes in pp collisions …
March 10, 2012
… at sqrt(s) = 7 TeV CMS Collaboration A search for microscopic black holes in pp collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 4.7 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. Events with large total transverse energy have […]
How fast black holes spin in quasars
March 9, 2012
Umberto Maio, Massimo Dotti, Margarita Petkova, Albino Perego, Marta Volonteri Mass and spin are often referred to as the two `hairs’ of astrophysical black holes, as they are the only two parameters needed to completely characterize them in General Relativity. The interaction between black holes and their environment is where complexity lies, as the relevant […]
Ultra-fast Outflows Help Monster Black Holes Shape Their Galaxies
February 28, 2012
curious correlation between the mass of a galaxy’s central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. An international team led by Francesco Tombesi at NASA’s Goddard Space Flight Center in Greenbelt, Md., now has identified a new type of black-hole-driven […]
Primordial seeds of supermassive black holes
February 25, 2012
Masahiro Kawasaki, Alexander Kusenko, Tsutomu T. Yanagida Supermassive black holes exist in the centers of galaxies, including Milky Way, but there is no compelling theory of their formation. Furthermore, observations of quasars imply that supermassive black holes have already existed at some very high redshifts, suggesting the possibility of their primordial origin. In a class […]
NASA’s Chandra Finds Fastest Wind From Stellar-Mass Black Hole
February 21, 2012
Astronomers using NASA’s Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding how this type of black hole behaves. The record-breaking wind is moving about 20 million mph, or about 3 percent of the speed of light. This […]
How to Take a Picture of a Black Hole
February 17, 2012
First, build a telescope the size of planet Earth ….. The Event Horizon Telescope (EHT) is an international project aimed at taking the first picture of a black hole, specifically of Sagittarius A*, the site of the black hole that is believed to be lurking at the center of our Milky Way galaxy….. ….. Getting there will […]
Black hole came from a shredded galaxy
February 15, 2012
This spectacular edge-on galaxy, called ESO 243-49, is home to an intermediate-mass black hole that may have been stripped off of a cannibalized dwarf galaxy. The estimated 20,000-solar-mass black hole lies above the galactic plane. This is an unlikely place for such a massive back hole to exist, unless it belonged to a small galaxy […]
‘Starbursts’ and black holes lead to biggest galaxies
January 25, 2012
Frenetic star-forming activity in the early Universe is linked to the most massive galaxies in today’s cosmos, new research suggests. This “starbursting” activity when the Universe was just a few billion years old appears to have been clamped off by the growth of supermassive black holes. An international team gathered hints of the mysterious “dark […]
Black Hole Remnants at the LHC
January 17, 2012
L. Bellagamba, R. Casadio, R. Di Sipio, V. Viventi We investigate possible signatures of black hole events at the LHC in the hypothesis that such objects will not evaporate completely, but leave a stable remnant. For the purpose of defining a reference scenario, we have employed the publicly available Monte Carlo generator CHARYBDIS2, in which […]
New telescope array will capture the first-ever photograph of a black hole
January 16, 2012
A new telescope array could allow scientists to photograph a black hole for the first time – teaming up 50 radio telescopes around the world into a global telescope that will capture the ‘shadow’ of a black hole for the first time. Scientists will meet on Wednesday 18th to discuss the project, which will also […]
Black holes without spacelike singularities
January 14, 2012
Mihalis Dafermos It is shown that for small, spherically symmetric perturbations of asymptotically flat two-ended Reissner-Nordstrom data for the Einstein-Maxwell-real scalar field system, the boundary of the dynamic spacetime which evolves is globally represented by a bifurcate null hypersurface across which the metric extends continuously. Under additional assumptions, it is shown that the Hawking mass […]
The fastest way to circle a black hole
January 4, 2012
Shahar Hod Black-hole spacetimes with a “photonsphere”, a hypersurface on which massless particles can orbit the black hole on circular null geodesics, are studied. We prove that among all possible trajectories (both geodesic and non-geodesic) which circle the central black hole, the null circular geodesic is characterized by the shortest possible orbital period as measured […]
Type III Dyson Sphere of Highly Advanced Civilizations ….
December 27, 2011
… around a Super Massive Black Hole Makoto Inoue, Hiromitsu Yokoo We describe a new system for a society of highly advanced civilizations around a super massive black hole (SMBH), as an advanced Type III “Dyson Sphere“, pointing out an efficient usage of energy for the advanced civilizations. SMBH also works as a sink for […]
NASA | RXTE Detects ‘Heartbeat’ Of Smallest Black Hole Candidate
December 19, 2011
http://youtu.be/YlHS-JlkYPI This animation compares the X-ray ‘heartbeats’ of GRS 1915 and IGR J17091, two black holes that ingest gas from companion stars. GRS 1915 has nearly five times the mass of IGR J17091, which at three solar masses may be the smallest black hole known. A fly-through relates the heartbeats to hypothesized changes in the […]
A gas cloud on its way toward the super-massive black hole in the Galactic Centre
December 14, 2011
Researchers have spotted a giant gas cloud spiralling into the supermassive black hole at our galaxy’s centre. Though it is known that black holes draw in everything nearby, it will be the first chance to see one consume such a cloud. As it is torn apart, the turbulent area around the black hole will become […]
Early Black Holes Grew Big Eating Cold, Fast Food
December 12, 2011
PITTSBURGH — Researchers at Carnegie Mellon University’s Bruce and Astrid McWilliams Center for Cosmology have discovered what caused the rapid growth of early supermassive black holes – a steady diet of cold, fast food. Computer simulations, completed using supercomputers at the National Institute for Computational Sciences and the Pittsburgh Supercomputing Center and viewed using GigaPan […]
Any black holes at the LHC?
December 3, 2011
Jonas Mureika, Piero Nicolini, Euro Spallucci We introduce analytical quantum gravity modifications of the production cross section for terascale black holes by employing an effective ultraviolet cut off ℓ. We find the new cross sections approach the usual “black disk” form at high energy, while they differ significantly near the fundamental scale from the standard […]
NASA’s Chandra Contributes to Black Hole Birth Announcement
November 17, 2011
New details about the birth of a famous black hole that took place millions of years ago have been uncovered, thanks to a team of scientists who used data from NASA’s Chandra X-ray Observatory as well as from radio, optical and other X-ray telescopes. Over three decades ago, Stephen Hawking placed — and eventually lost […]
Black hole noms: planetary treats for the galactic monster
November 9, 2011
What do black holes eat? And do supermassive black holes have fiercer appetites? Let’s remind ourselves of the facts. Lurking at the centre of the Milky Way is a monster, a giant black hole with a mass four million times that of the sun. With its immense gravitational pull, Galactic Central is a very dangerous place, with […]
May 4, 2013
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