15
Dec 11

RXTE detects 'Heartbeat' of smallest Black Hole candidate

Source: NASA

Artist's impression of a black hole's jets. Credit: NASA.

n international team of astronomers has identified a candidate for the smallest-known black hole using data from NASA's Rossi X-ray Timing Explorer (RXTE). The evidence comes from a specific type of X-ray pattern, nicknamed a "heartbeat" because of its resemblance to an electrocardiogram. The pattern until now has been recorded in only one other black hole system.

Named IGR J17091-3624 after the astronomical coordinates of its sky position, the binary system combines a normal star with a black hole that may weigh less than three times the sun's mass. That is near the theoretical mass boundary where black holes become possible.

Gas from the normal star streams toward the black hole and forms a disk around it. Friction within the disk heats the gas to millions of degrees, which is hot enough to emit X-rays. Cyclical variations in the intensity of the X-rays observed reflect processes taking place within the gas disk. Scientists think that the most rapid changes occur near the black hole's event horizon, the point beyond which nothing, not even light, can escape.

Astronomers first became aware of the binary system during an outburst in 2003. Archival data from various space missions show it becomes active every few years. Its most recent outburst started in February and is ongoing. The system is located in the direction of the constellation Scorpius, but its distance is not well established. It could be as close as 16,000 light-years or more than 65,000 light-years away.

The record-holder for wide-ranging X-ray variability is another black hole binary system named GRS 1915+105. This system is unique in displaying more than a dozen highly structured patterns, typically lasting between seconds and hours.(read more)

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14
Dec 11

VLT spots cloud being disrupted by black hole

Source: ESO Science Release eso1151


Simulation of the cloud being disrupted by a black hole.
Image credits: ESO/MPE/Marc Schartmann.

Astronomers using ESO’s Very Large Telescope have discovered a gas cloud with several times the mass of the Earth accelerating fast towards the black hole at the centre of the Milky Way. This is the first time ever that the approach of such a doomed cloud to a supermassive black hole has been observed. The results will be published in the 5 January 2012 issue of the journal Nature.(read more)

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20
Nov 11

Cygnus X-1: Chandra Adds to Black Hole Birth Announcement

Source: Chandra


Credit: Optical: DSS; Illustration: NASA/CXC/M.Weiss

On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. The black hole pulls material from a massive, blue companion star toward it. This material forms a disk (shown in red and orange) that rotates around the black hole before falling into it or being redirected away from the black hole in the form of powerful jets. (read source)

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7
Nov 11

Hubble Directly Observes the Disc Around a Black Hole

Source: ESA/Hubble Science Release heic1116


Image credits:NASA, ESA and J.A. Muñoz (University of Valencia)

A team of scientists has used the NASA/ESA Hubble Space Telescope to observe a quasar accretion disc — a brightly glowing disc of matter that is slowly being sucked into its galaxy’s central black hole. Their study makes use of a novel technique that uses gravitational lensing to give an immense boost to the power of the telescope. The incredible precision of the method has allowed astronomers to directly measure the disc’s size and plot the temperature across different parts of the disc.(read more)

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1
Oct 11

ESA's spacecraft reveals new anatomy around a black hole

Source: ESA


Artist's impression of the central engine of an active galaxy.
Image credits: NASA and M. Weiss (Chandra X-ray Center).

A fleet of spacecraft including ESA's XMM-Newton and Integral have shown unprecedented details close to a supermassive black hole. They reveal huge 'bullets' of gas being driven away from the 'gravitational monster'. (read more)

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2
Sep 11

Chandra Finds Nearest Pair Of Supermassive Black Holes

Source: NASA Chandra


Spiral galaxy NGC 3393.
Image credits: X-ray: NASA/CXC/SAO/G.Fabbiano et al; Optical: NASA/STScI

Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way. Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon. The black holes are located near the center of the spiral galaxy NGC 3393. Separated by only 490 light years, the black holes are likely the remnant of a merger of two galaxies of unequal mass a billion or more years ago. (read more)

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25
Aug 11

Swift satellite spots Black Hole devouring a Star

Source: NASA News/SWIFT


Image credit: NRAO/CfA/Zauderer et al

Two studies appearing in the August 25 issue of th journal Nature provide new insights into a cosmic accident that has been streaming X-rays toward Earth since late March. NASA's Swift satellite first alerted astronomers to intense and unusual high-energy flares from the new source in the constellation Draco. (read more)

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22
Aug 11

Black holes and pulsars could reveal extra dimensions

Source: New Scientist

Making a black hole let go of anything is a tall order. But their grip may slowly weaken if the universe has extra dimensions, something that pulsars could help us to test.

String theory, which attempts to unify all the known forces, calls for extra spatial dimensions beyond the three we experience. Testing the theory has proved difficult, however.

Now John Simonetti of Virginia Tech in Blacksburg and colleagues say black holes orbited by neutron stars called pulsars could do just that - if cosmic surveys can locate such pairings. "The universe contains 'experimental' setups we cannot produce on Earth," he says.

Black holes are predicted to fritter away their mass over time by emitting particles, a phenomenon called Hawking radiation. Without extra dimensions, this process is predicted to be agonisingly slow for run-of-the-mill black holes weighing a few times as much as the sun, making it impossible to measure.

Extra dimensions would give the particles more ways to escape, speeding up the process. This rapid weight loss would loosen a black hole's gravitational grip on any orbiting objects, causing them to spiral outwards by a few metres per year, the team calculates (The Astrophysical Journal, DOI: 10.1088/2041-8205/737/2/l28).

A pulsar orbiting a black hole could reveal this distancing. That's because the lighthouse-like pulses of radiation they emit would vary slightly depending on the size of the star's orbit. (read source)

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30
Jul 11

Black Hole collision may have set off fireworks in the Milky Way

Source: Science Magazine AAAS


Detailed view of the Milky Way's core.
Image credits: NASA/ESA/SSC/ CXC/ STScI

The Milky Way's center houses a supermassive black hole so sleepy that it probably hasn't swallowed a decent meal for years. Yet a growing body of evidence indicates that the now-dormant beast, about as massive as 4 million suns, fueled a firestorm of activity just a few million years ago, including the sustained emission of some of the highest energy radiation in the universe. A new study offers a dramatic explanation for these past fireworks: The sleeping giant woke when a smaller black hole from another galaxy smashed into it.(read more)

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28
Jul 11

Chandra Observatory images gas flowing toward black hole

Source: NASA/Chandra


Composite image of galaxy NGC 3115.
Image credits: X-ray: NASA/CXC/Univ. of Alabama/K. Wong et al; Optical: ESO/VLT.

The flow of hot gas toward a black hole has been clearly imaged for the first time in X-rays. The observations from NASA's Chandra X-ray Observatory will help tackle two of the most fundamental problems in modern astrophysics: understanding how black holes grow and how matter behaves in their intense gravity.

The black hole is at the center of a large galaxy known as NGC 3115, which is located about 32 million light years from Earth. A large amount of previous data has shown material falling toward and onto black holes, but none with this clear a signature of hot gas.

By imaging the hot gas at different distances from this supermassive black hole, astronomers have observed a critical threshold where the motion of gas first becomes dominated by the black hole's gravity and falls inward. This distance from the black hole is known as the "Bondi radius." (read more)

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13
Jul 11

What Activates a Supermassive Black Hole?

Source: ESO Science Release eso1124


COSMOS field imaged by the Canada France Hawaii Telescope (CFHT).
Image credits: CFHT/IAP/Terapix/CNRS/ESO.

 

A new study combining data from ESO’s Very Large Telescope and ESA’s XMM-Newton X-ray space observatory has turned up a surprise. Most of the huge black holes in the centres of galaxies in the past 11 billion years were not turned on by mergers between galaxies, as had been previously thought. (read more)

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20
Jun 11

Chandra finds massive black holes common in early Universe

Source: Chandra X-Ray Observatory


Illustration of Baby Black Hole.
Image credit: NASA/CXC/A.Hobart.

A composite image from NASA's Chandra X-ray Observatory and Hubble Space Telescope (HST) combines the deepest X-ray, optical and infrared views of the sky. Using these images, astronomers have obtained the first direct evidence that black holes are common in the early Universe and shown that very young black holes grew more aggressively than previously thought. (read more)

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17
Jun 11

Black hole caught eating a star, gamma-ray flash hints

Source: National Geographic/Andrew Fazekas


Artist's impression of a star's accretion made by a black hole.
Image credits: Mark A. Garlick, University of Warwick

A huge "belch" of radiation from a supermassive black hole indicates that the cosmic monster recently devoured a star, scientists say.

Earlier this year astronomers spied a burst of high-energy gamma rays emanating from the center of a dwarf galaxy 3.8 billion light-years away. The odd flash, dubbed Sw 1644+57, is one is the brightest and longest gamma ray bursts (GRBs) yet seen. (read more)

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13
Jun 11

Nearby galaxy boasts two monster black holes, both active

Source: NASA-SWIFT


Markarian 739 in visible light.
Image credit: SDSS.

A study using NASA's Swift satellite and the Chandra X-ray Observatory has found a second supersized black hole at the heart of an unusual nearby galaxy already known to be sporting one.

The galaxy, which is known as Markarian 739 or NGC 3758, lies 425 million light-years away toward the constellation Leo. Only about 11,000 light-years separate the two cores, each of which contains a black hole gorging on infalling gas.

The study will appear in a forthcoming issue of The Astrophysical Journal Letters.(read more)

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24
May 11

Black holes spin faster and faster

Source: Royal Astronomical Society


Artist’s impression of  jets emerging from a supermassive black hole.
Credit: Dana Berry / STScI

Two UK astronomers have found that the giant black holes in the centre of galaxies are on average spinning faster than at any time in the history of the Universe. Dr Alejo Martinez-Sansigre of the University of Portsmouth and Prof. Steve Rawlings of the University of Oxford made the new discovery by using radio, optical and X-ray data. They publish their findings in the journal Monthly Notices of the Royal Astronomical Society.(read more)

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21
May 11

Radio Telescopes capture best-ever snapshot of Black Hole Jets

Source: NASA News


Jets and radio-emitting lobes emanating from Centaurus A's central black hole.
Image credits: ESO/WFI (visible); NASA/CXC/CfA/R.Kraft et al. (X-ray);
MPIfR/ESO/APEX/A.Weiss et al. (microwave);

An international team, using radio telescopes located throughout the Southern Hemisphere has produced the most detailed image of particle jets erupting from a supermassive black hole in a nearby galaxy.

The new image shows a region less than 4.2 light-years across -- less than the distance between our sun and the nearest star. Radio-emitting features as small as 15 light-days can be seen, making this the highest-resolution view of galactic jets ever made. The study will appear in the June issue of Astronomy and Astrophysics and is available online.(read more)

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24
Mar 11

Integral spots matter a millisecond from doom

Source: ESA


Artist's impression of the Cygnus X-1 black hole system. Credits: ESA.

ESA’s Integral gamma-ray observatory has spotted extremely hot matter just a millisecond before it plunges into the oblivion of a black hole. But is it really doomed? These unique observations suggest that some of the matter may be making a great escape.(read more)

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10
Feb 11

Arp 147: Giant Ring of Black Holes

Source: NASA/Chandra


Arp 147 contains a spiral galaxy (right) that collided with an elliptical galaxy (left), triggering a wave of star formation.
Image credits: X-ray: NASA/CXC/MIT/S.Rappaport et al, Optical: NASA/STScI

Just in time for Valentine's Day comes a new image of a ring -- not of jewels -- but of black holes. This composite image of Arp 147, a pair of interacting galaxies located about 430 million light years from Earth, shows X-rays from the NASA's Chandra X-ray Observatory (pink) and optical data from the Hubble Space Telescope (red, green, blue) produced by the Space Telescope Science Institute (STScI). (read more)

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28
Dec 10

How Often do Giant Black Holes Become Hyperactive?

Source: NASA/Chandra


Composite images of galaxies Abell 644, left, and galaxy SDSS J1021+131.
Image credit: X-ray: NASA/CXC/Northwestern Univ/D.Haggard et al. Optical: SDSS

A new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. This discovery clarifies how supermassive black holes grow and could have implications for how the giant black hole at the center of the Milky Way will behave in the future.

Most galaxies, including our own, are thought to contain supermassive black holes at their centers, with masses ranging from millions to billions of times the mass of the Sun. For reasons not entirely understood, astronomers have found that these black holes exhibit a wide variety of activity levels: from dormant to just lethargic to practically hyper.

The most lively supermassive black holes produce what are called "active galactic nuclei," or AGN, by pulling in large quantities of gas. This gas is heated as it falls in and glows brightly in X-ray light. (read more)

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17
Nov 10

Youngest-Ever Nearby Black Hole Discovered

Credit: NASA Science


This composite image shows a supernova within the galaxy M100 that may contain the youngest known black hole in our cosmic neighborhood. In this image, Chandra’s X-rays are colored gold, while optical data from ESO’s Very Large Telescope are shown in red, green, and blue, and infrared data from Spitzer are red. The location of the supernova, known as SN 1979C, is labeled. Image credits: X-ray: NASA/CXC/SAO/D.Patnaude et al, Optical: ESO/VLT, Infrared: NASA/JPL/Caltech

Astronomers using NASA's Chandra X-ray Observatory have found evidence of the youngest black hole known to exist in our cosmic neighborhood. The 30-year-old object provides a unique opportunity to watch a black hole develop from infancy. (read more)

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