K-line (spectrometry)
Encyclopedia
The K-line is a spectral peak in astronomical
spectrometry used, along with the L-line, to observe and describe the light spectrum star
s.
The K-line is associated with iron
(Fe
), and is described as being from emissions at ~6.14keV (thousands of electron volts).
On 5 October 2006 NASA
announced the results of research using the Japan
ese JAXA Suzaku
satellite, after earlier work with the XMM-Newton
satellite. "The observations include clocking the speed of a black hole's spin rate and measuring the angle at which matter pours into the void, as well as evidence for a wall of X-ray light pulled back and flattened by gravity."
The study teams observed X ray emissions from the "broad iron K line" near the event horizon
of several super-massive black hole
s of galaxies
called MCG-6-30-15 and MCG-5-23-16. The normally narrow K-line is broadened by the doppler shift (red shift
or blue shift
) of the X ray light emitted by matter being affected by the gravity of the black hole. The results coincide with predictions Einstein's theory
of general relativity
. The teams were led by Andrew Fabian
of Cambridge University, England
, and James Reeves of NASA's Goddard Space Flight Center
, Greenbelt, Maryland
, United States
.
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
spectrometry used, along with the L-line, to observe and describe the light spectrum star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s.
The K-line is associated with iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
(Fe
FE
Fe or FE may refer to:* Iron * Fe , the f-rune of the Younger Futhark* Fe * Fe * "Fe" , a song by Jorge González...
), and is described as being from emissions at ~6.14keV (thousands of electron volts).
On 5 October 2006 NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
announced the results of research using the Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese JAXA Suzaku
Suzaku
Suzaku may refer to:* Suzaku, the Japanese name for the Chinese Vermilion Bird , bird guardian of the South*Emperor Suzaku, emperor of Japan*SUZAK Inc., also known as Suzaku, a video game developer* Suzaku Avenue, one of the ancient main streets e.g...
satellite, after earlier work with the XMM-Newton
XMM-Newton
The XMM-Newton is an orbiting X-ray observatory launched by ESA in December 1999 on a Ariane 5 rocket...
satellite. "The observations include clocking the speed of a black hole's spin rate and measuring the angle at which matter pours into the void, as well as evidence for a wall of X-ray light pulled back and flattened by gravity."
The study teams observed X ray emissions from the "broad iron K line" near the event horizon
Event horizon
In general relativity, an event horizon is a boundary in spacetime beyond which events cannot affect an outside observer. In layman's terms it is defined as "the point of no return" i.e. the point at which the gravitational pull becomes so great as to make escape impossible. The most common case...
of several super-massive black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
s of galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
called MCG-6-30-15 and MCG-5-23-16. The normally narrow K-line is broadened by the doppler shift (red shift
Red shift
-Science:* Redshift, the increase of wavelength of detected electromagnetic radiation with respect to the original wavelength of the emission* Red shift, an informal term for a bathochromic shift...
or blue shift
Blue shift
A blueshift is any decrease in wavelength ; the opposite effect is referred to as redshift. In visible light, this shifts the colour from the red end of the spectrum to the blue end...
) of the X ray light emitted by matter being affected by the gravity of the black hole. The results coincide with predictions Einstein's theory
Theory
The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
of general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
. The teams were led by Andrew Fabian
Andrew Fabian
Andrew Christopher Fabian, OBE, FRS is a British astronomer and astrophysicist. He is a Royal Society Research Professor at the Institute of Astronomy, Cambridge, and Vice-Master of Darwin College, Cambridge. He was the President of the Royal Astronomical Society from May 2008 through to 2010...
of Cambridge University, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, and James Reeves of NASA's Goddard Space Flight Center
Goddard Space Flight Center
The Goddard Space Flight Center is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately northeast of Washington, D.C. in Greenbelt, Maryland, USA. GSFC,...
, Greenbelt, Maryland
Greenbelt, Maryland
Greenbelt is a city in Prince George's County, Maryland, United States. Contained within today's City of Greenbelt is the historic planned community now known locally as "Old Greenbelt" and designated as the Greenbelt Historic District...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
External links
- NASA report on Suzaku research dated 5 October 2006 - retrieved 11 October 2006