MessageToEagle.com -
A cosmic "ghost" lurking around a distant supermassive black hole provides astronomers with valuable information about the early Universe.
We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge
University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something -
in this case what was happening in this galaxy billions of year ago."
The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over
10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate.
Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its
central black hole in the form of jets of energetic particles traveling at almost the speed of light.
When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years,
the radio signal faded from view as the electrons radiated away their energy.
However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang -
the cosmic background radiation.
Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band.
This process produces an extended X-ray source that lasts for another 30 million years or so.
"This ghost tells us about the black hole's eruption long after it has died," said co-author Scott Chapman, also of Cambridge University.
"This means we don't have to catch the black holes in the act to witness the big impact they have."
This is the first X-ray ghost ever seen after the demise of radio-bright jets. Astronomers have observed extensive X-ray emission with a similar origin,
but only from galaxies with radio emission on large scales, signifying continued eruptions. In HDF 130, only a point source is detected in radio images,
coinciding with the massive elliptical galaxy seen in its optical image. This radio source indicates the presence of a growing supermassive black hole.
HDF is a diffuse X-ray source located over 10 billion light years away.
This ghostly source was generated by a powerful eruption from a supermassive black hole in a large galaxy.
Such X-ray ghosts last longer than the original black hole eruptions allowing the impact of these outbursts to be more easily studied.
Credit: X-ray (NASA/CXC/IoA/A.Fabian et al.); Optical (SDSS), Radio (STFC/JBO/MERLIN)
"This result hints that the X-ray sky should be littered with such ghosts," said co-author Caitlin Casey, also of Cambridge, "especially if black
hole eruptions are as common as we think they are in the early Universe."
The power contained in the black hole eruption was likely to be considerable, equivalent to about a billion supernovas. The energy is dumped into
the surroundings and transports and heats the gas.
"Even after the ghost disappears, most of the energy from the black hole's eruption remains", said Fabian. "Because they're so powerful, these
eruptions can have profound effects lasting for billions of years."
The details of Chandra's data of HDF 130 helped secure its true nature. For example, in X-rays, HDF 130 has a cigar-like shape that extends for
some 2.2 million light years. The linear shape of the X-ray source is consistent with the shape of radio jets and not with that of a galaxy cluster,
which is expected to be circular. The energy distribution of the X-rays is also consistent with the interpretation of an X-ray ghost.
20,000-Solar-Mass Black Hole Found At The Core
Of A Now-Destroyed Dwarf Galaxy
The formation of stellar-mass black holes through the collapse of massive stars is well accepted. However, it is not yet completely
clear how the supermassive objects are formed.
They may form through the merger of smaller, intermediate-mass black holes (IMBHs) weighing hundreds to thousands of suns.
Black Holes With No 'Table Manners' Eat Two Courses At Once!
It is still unknown how the supermassive black holes (SMBH) in galaxy centres accrete gas and grow.
Researchers from the University of Leicester (UK) and Monash University in Australia have investigated how some black holes got so big so fast that they are billions of times heavier than the sun.
Cosmic Robbers: Black Hole Jets May Cause
Galaxy NGC 3801 To Die And Lose Its Stars
Armchair explorers of the cosmos can now have at their fingertips the nearly 2,000 distant planetary systems discovered by NASA's Kepler Mission.
Now available for free from the iTunes App Store, Kepler Explorer was developed through the OpenLab initiative at UC Santa Cruz,
which brought together faculty and students in astrophysics, art, and technology for a summer institute last year.
New Kepler Explorer:
View The 1,790 Distant Planetary Systems - For Free!
Armchair explorers of the cosmos can now have at their fingertips the nearly 2,000 distant planetary systems discovered by NASA's Kepler Mission.
Now available for free from the iTunes App Store, Kepler Explorer was developed through the OpenLab initiative at UC Santa Cruz,
which brought together faculty and students in astrophysics, art, and technology for a summer institute last year.
Warp-Speed Planets Are Some Of The Fastest Objects In The Milky Way
Warped planets are some of the fastest objects in the Milky Way and they zoom through space near the speed of light.
Some years ago astronomers were astonished when they they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour.
The discovery intrigued theorists, who wondered: If a star can get tossed outward at such an extreme velocity, could the same thing happen to planets?
Though the universe is filled with billions upon billions of stars, the discovery of a single variable star in 1923 altered the
course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.
Bright Star In The Constellation Lyra Is Cooler Than The Human Body
The coldest class of stars have temperatures as cool as the human body.
Astronomers hunted these dark orbs, termed Y dwarfs, for more than a decade without success.
When viewed with a visible-light telescope, they are nearly impossible to see.
Thermonuclear Burning In A Neutron Star Detected For The First Time!
It's a very important discovery!
For the first time, an international team of scientists have detected all phases of thermonuclear burning in a
neutron star, located close to the center of the galaxy in the globular cluster Terzan 5.
MessageToEagle.com -
A cosmic "ghost" lurking around a distant supermassive black hole provides astronomers with valuable information about the early Universe.
The formation of stellar-mass black holes through the collapse of massive stars is well accepted. However, it is not yet completely
clear how the supermassive objects are formed.
They may form through the merger of smaller, intermediate-mass black holes (IMBHs) weighing hundreds to thousands of suns.
It is still unknown how the supermassive black holes (SMBH) in galaxy centres accrete gas and grow.
Researchers from the University of Leicester (UK) and Monash University in Australia have investigated how some black holes got so big so fast that they are billions of times heavier than the sun.
Armchair explorers of the cosmos can now have at their fingertips the nearly 2,000 distant planetary systems discovered by NASA's Kepler Mission.
Now available for free from the iTunes App Store, Kepler Explorer was developed through the OpenLab initiative at UC Santa Cruz,
which brought together faculty and students in astrophysics, art, and technology for a summer institute last year.
Armchair explorers of the cosmos can now have at their fingertips the nearly 2,000 distant planetary systems discovered by NASA's Kepler Mission.
Now available for free from the iTunes App Store, Kepler Explorer was developed through the OpenLab initiative at UC Santa Cruz,
which brought together faculty and students in astrophysics, art, and technology for a summer institute last year.
Warped planets are some of the fastest objects in the Milky Way and they zoom through space near the speed of light.
Some years ago astronomers were astonished when they they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour.
The discovery intrigued theorists, who wondered: If a star can get tossed outward at such an extreme velocity, could the same thing happen to planets?
Though the universe is filled with billions upon billions of stars, the discovery of a single variable star in 1923 altered the
course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.
The coldest class of stars have temperatures as cool as the human body.
Astronomers hunted these dark orbs, termed Y dwarfs, for more than a decade without success.
When viewed with a visible-light telescope, they are nearly impossible to see.
It's a very important discovery!
For the first time, an international team of scientists have detected all phases of thermonuclear burning in a
neutron star, located close to the center of the galaxy in the globular cluster Terzan 5.