SRON: Extreme gravity effects revealed by oxygen

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bystander
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SRON: Extreme gravity effects revealed by oxygen

Post by bystander » Mon Jun 21, 2010 8:31 pm

Extreme gravity effects revealed by oxygen for the first time
Netherlands Institute for Space Research (SRON) - 21 June 2010
Neutron star 'eats' oxygen-rich white dwarf in a peculiar binary system

Astronomers from SRON Netherlands Institute for Space Research and Utrecht University have found blurred oxygen signatures in the X-rays from a neutron star that 'eats' a white dwarf. For the first time the effects of extreme gravity are revealed by oxygen instead of iron atoms. The results of the research appear in the Monthly Notices of the Royal Astronomical Society (MNRAS).

Although strong gravity near neutron stars and black holes has been studied before in a similar way, this result is unique. Until now, only blurred X-ray signatures of iron atoms have been observed in the X-rays from a neutron star. However, the characteristics of these so called 'iron lines' are disputed, which makes them less suited for extreme gravity field measurements.

The neutron star has been studied before but now Oliwia Madej, PhD student at Utrecht University and SRON, has found blurred oxygen signatures in the X-rays from the star. She made this discovery in an archival observation performed by ESA’s XMM-Newton observatory, which is equipped with the SRON reflection grating spectrometer (RGS) that is extemely sensitive in these particular wavelenghts. The research was carried out under supervision of SRON researcher Peter Jonker.

The neutron star that the astronomers observed is part of a binary system called 4U 0614+091. In the binary, the neutron star and a white dwarf closely orbit each other in roughly 50 minutes. The white dwarf - basically a burnt out star - orbits at such a small distance from the neutron star that the oxygen-rich gas is pulled off the dwarf and starts closely swirling around the neutron star in a disk.
Extreme gravity

'Normally, hot oxygen atoms emit X-rays at a specific energy,' Madej explains. 'But because of the extreme gravity and the hot gas in the disk around the neutron star, this oxygen signature in the X-ray data is blurred.' From the shape of the blur Madej tried to estimate the inner radius of the oxygen-rich disk around the neutron star, which should give an idea of the maximum radius that the neutron star could possibly have.

'Unfortunately, the current data are not yet good enough to give a definitive answer on the size of a neutron star,' Peter Jonker admits. 'To determine this in greater detail we need more observation time. And when we find the signature of iron molecules as well, we can now compare the characteristics of the two emission lines. Measured together, uncertainties about the measurements of the iron line can be taken away, which will guide the interpretation in other systems where only iron has been seen. All in all our observations are definitely an important step on the way towards a better understanding of the extreme conditions around and inside a neutron star.'

Neutron star

Neutron stars – shaped out of the collapsing cores of massive stars - are the most compact objects with a surface in the universe. A neutron star has a slightly higher mass compared to a white dwarf, but the matter is squeezed into a ball of only 10-20 km in diameter. At these high densities, normal atoms cannot exist anymore. Anything denser would collapse into a black hole. Therefore, astronomers are very interested in the state of the matter inside a neutron star.
A relativistically broadened O VIII Lyalpha line in the ultra-compact X-ray binary 4U 0614+091

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"Sucking all the oxygen out of the room"

Post by neufer » Mon Jun 21, 2010 9:03 pm

http://en.wikipedia.org/wiki/Retroville wrote:
The Adventures of Jimmy Neutron: (Wonder)Boy Genius
is an American animated television series, and spin-off
of the Academy Award nominated computer-animated movie.

Image

James "Jimmy" Isaac Neutron (Debi Derryberry) is the main protagonist of the show. He is a 10-year-old American boy with a stunning IQ and a love for science. Usually, his inventions cause more harm than benefit for the city of Retroville, but that never stops him from trying. Most of the time, he's busy saving the city from his own experiments gone wrong. He is best friends with Carl and Sheen. Throughout the series there are hints that he has feelings for Cindy Vortex.

Goddard (Frank Welker) is Jimmy's trusty robotic dog. Considering he's made of sprockets, circuits and widgets, Goddard makes one great man's best friend. Plus, unlike his real-life canine cousins, Goddard can transform into a whole slew of useful tools, vehicles and other gadgets for Jimmy. Goddard's still got a few kinks to work out, but otherwise, this digital dog is the perfect (cyber) canine companion. Goddard is named after Robert Goddard, the "Father of Rocketry".

Hugh Neutron (Mark DeCarlo) is Jimmy's dad. He is very obsessed with ducks and loves pie. He tries to spend as much time with Jimmy as possible and is very intrigued by his inventions. He is really goofy but loves his family, including his wife Judy who he often calls "Sugar Booger."

Judy Neutron (Megan Cavanagh) Judy is Jimmy's mom. She is loving and is the stereotypical 50's housewife. Her style is also typical and her hair is in a distinctive cut, usually noticed in a few episodes. Of course she loves her family, and gives Jimmy advice about his life and his adventures.>>
Art Neuendorffer

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Beyond
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Re: SRON: Extreme gravity effects revealed by oxygen

Post by Beyond » Wed Jun 23, 2010 1:01 am

bystander wrote:Neutron star 'eats' oxygen-rich white dwarf in a peculiar binary system
Kinda gives a whole new meaning to deep breathing, doesn't it?
To find the Truth, you must go Beyond.

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