Neutron stars join the black hole jet setJune 28, 2007NASA's Chandra X-ray Observatory has revealed an X-ray jet blasting away from a neutron star in a binary system. This discovery may help astronomers understand how neutron stars as well as black holes can generate powerful beams of relativistic particles. The jet was found in Circinus X-1, a system where a neutron star is in orbit around a star several times the mass of the Sun, about 20,000 light years from Earth. A neutron star is an extremely dense remnant of an exploded star consisting of tightly packed neutrons. Many jets have been found originating near black holes - both the supermassive and stellar-mass variety - but the Circinus X-1 jet is the first extended X-ray jet associated with a neutron star in a binary system. This detection shows that the unusual properties of black holes - such as presence of an event horizon and the lack of an actual surface - may not be required to form powerful jets. "Gravity appears to be the key to creating these jets, not some trick of the event horizon," said Sebastian Heinz of the University of Wisconsin at Madison, who led the study. The discovery of this jet with Chandra also reveals how efficient neutron stars can be as cosmic power factories. Heinz and his colleagues estimate that a surprisingly high percentage of the energy available from material falling onto the neutron star is converted into powering the jet. "In terms of energy efficiency across the Universe, this result shows that neutron stars are near the top of the list," said Norbert Schulz, a coauthor from the Massachusetts Institute of Technology in Cambridge. "This jet is almost as efficient as one from a black hole." The Chandra results also help to explain the origin of diffuse lobes of radio emission previously detected around Circinus X-1. The team found the X-ray jets of high-energy particles are powerful enough to create and maintain these balloons of radio-emitting gas. "We've seen enormous radio clouds around supermassive black holes at the centers of galaxies," said Heinz. "What's unusual here is that this pocket-sized version, relatively speaking, is being powered by a neutron star, not a black hole." The main evidence for the newly found jet comes in two extended features in the Chandra data. These two fingers of X-ray emission are separated by about 30 degrees and may represent the outer walls of a wide jet. When overlapped with radio images, these X-ray features, which are at least five light years from the neutron star, closely trace the outline of the radio jet. Another interpretation is that these two features represent two separate, highly collimated jets produced at different times by a precessing neutron star. That is, the neutron star wobbles like a top as it spins and the jet fires at different angles at different times. Jet precession is also consistent with radio observations taken at different times, which show varying orientation angles of the jet. If the precession scenario is correct, Circinus X-1 would possess one of the longest, narrowest jets found in X-ray binary systems to date, representing yet another way in which neutron stars can rival and even outdo their larger black hole relatives. Chandra X-ray Center |
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| Related Neutron Star Current Events and Neutron Star News Articles Carbon atmosphere discovered on neutron star Evidence for a thin veil of carbon has been found on the neutron star in the Cassiopeia A supernova remnant. This discovery, made with NASA's Chandra X-ray Observatory, resolves a ten-year mystery surrounding this object. Fermi telescope caps its first year with a glimpse of space-time During its first year of operations, NASA's Fermi Gamma Ray Space Telescope mapped the extreme sky with unprecedented resolution and sensitivity. Gamma-ray photon race ends in dead heat; Einstein wins this round Racing across the universe for the last 7.3 billion years, two gamma-ray photons arrived at NASA's orbiting Fermi Gamma-ray Space Telescope within nine-tenths of a second of one another. XMM-Newton uncovers a celestial Rosetta stone ESA's XMM-Newton orbiting X-ray telescope has uncovered a celestial Rosetta stone: the first close-up of a white dwarf star, circling a companion star, that could explode into a particular kind of supernova in a few million years. Keck Study Sheds New Light on 'Dark' Gamma-ray Bursts Gamma-ray bursts are the universe's biggest explosions, capable of producing so much light that ground-based telescopes easily detect it billions of light-years away. Rare radio supernova in nearby galaxy is nearest supernova in five years The chance discovery last month of a rare radio supernova - an exploding star seen only at radio wavelengths and undetected by optical or X-ray telescopes - underscores the promise of new, more sensitive radio surveys to find supernovas hidden by gas and dust. Astronomers catch a star being revved-up Researchers have witnessed a star being transformed into an object that spins at almost 600 times a second using telescopes in the USA and the Netherlands, and CSIRO's Parkes telescope in Australia. Star crust 10 billion times stronger than steel, IU physicist finds Research by a theoretical physicist at Indiana University shows that the crusts of neutron stars are 10 billion times stronger than steel or any other of the earth's strongest metal alloys. A young pulsar shows its hand A small, dense object only twelve miles in diameter is responsible for this beautiful X-ray nebula that spans 150 light years. NASA's Fermi Telescope Reveals Best-Ever View of Gamma-Ray Sky A new map combining nearly three months of data from NASA's Fermi Gamma-ray Space Telescope is giving astronomers an unprecedented look at the high-energy cosmos. To Fermi's eyes, the universe is ablaze with gamma rays from sources ranging from within the solar system to galaxies billions of light-years away. More Neutron Star Current Events and Neutron Star News Articles |
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