The regions around supermassive black holes shine
brightly in X-rays. Some of this radiation comes from a surrounding disk, and
most comes from the corona, pictured here in this artist's concept as the white
light at the base of a jet. This is one of a few possible shapes predicted for
coronas.
Image Credit:
NASA/JPL-Caltech
This plot of data captured by NASA's Nuclear
Spectroscopic Telescope Array, or NuSTAR, shows X-ray light streaming from
regions near a supermassive black hole known as Markarian 335.
Image Credit:
NASA/JPL-Caltech/Institute for Astronomy, Cambridge
Feature Link:
NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has captured an extreme
and rare event in the regions immediately surrounding a supermassive black hole.
A compact source of X-rays that sits near the black hole, called the corona, has
moved closer to the black hole over a period of just days.
"The corona recently collapsed in toward the black hole, with the result that
the black hole's intense gravity pulled all the light down onto its surrounding
disk, where material is spiraling inward," said Michael Parker of the Institute
of Astronomy in Cambridge, United Kingdom, lead author of a new paper on the
findings appearing in the Monthly Notices of the Royal Astronomical Society.
As the corona shifted closer to the black hole, the gravity of the black hole
exerted a stronger tug on the X-rays emitted by it. The result was an extreme
blurring and stretching of the X-ray light. Such events had been observed
previously, but never to this degree and in such detail.
Supermassive black holes are thought to reside in the centers of all
galaxies. Some are more massive and rotate faster than others. The black hole in
this new study, referred to as Markarian 335, or Mrk 335, is about 324 million
light-years from Earth in the direction of the Pegasus constellation. It is one
of the most extreme of the systems for which the mass and spin rate have ever
been measured. The black hole squeezes about 10 million times the mass of our
sun into a region only 30 times the diameter of the sun, and it spins so rapidly
that space and time are dragged around with it.
Even though some light falls into a supermassive black hole never to be seen
again, other high-energy light emanates from both the corona and the surrounding
accretion disk of superheated material. Though astronomers are uncertain of the
shape and temperature of coronas, they know that they contain particles that
move close to the speed of light.
NASA's Swift satellite has monitored Mrk 335 for years, and recently noted a
dramatic change in its X-ray brightness. In what is called a
target-of-opportunity observation, NuSTAR was redirected to take a look at
high-energy X-rays from this source in the range of 3 to 79 kiloelectron volts.
This particular energy range offers astronomers a detailed look at what is
happening near the event horizon, the region around a black hole from which
light can no longer escape gravity's grasp.
Follow-up observations indicate that the corona still is in this close
configuration, months after it moved. Researchers don't know whether and when
the corona will shift back. What is more, the NuSTAR observations reveal that
the grip of the black hole's gravity pulled the corona's light onto the inner
portion of its superheated disk, better illuminating it. Almost as if somebody
had shone a flashlight for the astronomers, the shifting corona lit up the
precise region they wanted to study.
The new data could ultimately help determine more about the mysterious nature
of black hole coronas. In addition, the observations have provided better
measurements of Mrk 335's furious relativistic spin rate. Relativistic speeds
are those approaching the speed of light, as described by Albert Einstein's
theory of relativity.
"We still don't understand exactly how the corona is produced or why it
changes its shape, but we see it lighting up material around the black hole,
enabling us to study the regions so close in that effects described by
Einstein's theory of general relativity become prominent," said NuSTAR Principal
Investigator Fiona Harrison of the California Institute of Technology (Caltech)
in Pasadena. "NuSTAR's unprecedented capability for observing this and similar
events allows us to study the most extreme light-bending effects of general
relativity."
NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet
Propulsion Laboratory (JPL) in Pasadena for NASA's Science Mission Directorate
in Washington. The spacecraft was built by Orbital Sciences Corporation in
Dulles, Virginia. Its instrument was built by a consortium including Caltech,
JPL, the University of California, Berkeley, Columbia University, New York,
NASA's Goddard Space Flight Center, Greenbelt, Maryland, the Danish Technical
University in Denmark, Lawrence Livermore National Laboratory in Livermore,
California, ATK Aerospace Systems in Goleta, California, and with support from
the Italian Space Agency (ASI) Science Data Center.
NuSTAR's mission operations center is at UC Berkeley, with the ASI providing
its equatorial ground station located in Malindi, Kenya. The mission's outreach
program is based at Sonoma State University, Rohnert Park, California. NASA's
Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.
For more information on NuSTAR, visit:
http://www.nasa.gov/nustar
NASA's RXTE Satellite Decodes
the Rhythm of an Unusual Black Hole
Astronomers have uncovered rhythmic pulsations from a rare type of black hole
12 million light-years away by sifting through archival data from NASA's Rossi
X-ray Timing Explorer (RXTE) satellite.
The signals have helped astronomers identify an unusual midsize black hole called M82 X-1, which is the brightest X-ray source in a galaxy known as Messier 82. Most black holes formed by dying stars are modestly-sized, measuring up to around 25 times the mass of our sun. And most large galaxies harbor monster, or supermassive, black holes that contain tens of thousands of times more mass.
“Between the two extremes of stellar and supermassive black holes, it's a real desert, with only about half a dozen objects whose inferred masses place them in the middle ground," said Tod Strohmayer, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Astronomers from Goddard and
the University of Maryland, College Park (UMCP) have suspected M82 X-1 of being
midsize for at least a decade, but compelling evidence excluding it from being a
stellar black hole proved elusive.
"For reasons that are very hard to understand, these objects have resisted standard measurement techniques," said Richard Mushotzky, a professor of astronomy at UMCP.
By going over past RXTE observations, the astronomers found specific changes in brightness that helped them determine M82 X-1 measures around 400 solar masses.
As gas falls toward a black hole, it heats up and emits X-rays. Variations in X-ray brightness reflect changes occurring in the gas. The most rapid fluctuations happen near the brink of the black hole’s event horizon, the point beyond which nothing, not even light, can escape.
Astronomers call these rhythmic pulses quasi-periodic oscillations, or QPOs. For stellar black holes, astronomers have established that the larger the mass, the slower the QPOs, but they could not be sure what they were seeing from M82 X-1 was an extension of this pattern.
"When we study fluctuations in X-rays from many stellar-mass black holes, we see both slow and fast QPOs, but the fast ones often come in pairs with a specific 3:2 rhythmic relationship," explained Dheeraj Pasham, UMCP graduate student. For every three pulses from one member of a QPO pair, its partner pulses twice.
By analyzing six years of RXTE data, the team located X-ray variations that reliably repeat about 5.1 and 3.3 times a second, a 3:2 relationship. The combined presence of slow QPOs and a faster pair in a 3:2 rhythm sets a standard scale allowing astronomers to extend proven relationships used to determine the masses of stellar-mass black holes.
The results of the study were published online in the Aug. 17 issue of the journal Nature.
Launched in late 1995 and decommissioned in 2012, RXTE is one of NASA's longest-serving astrophysics missions. Its legacy of unique measurements continues to provide researchers with valuable insights into the extreme environments of neutron stars and black holes.
A new NASA X-ray mission called the Neutron Star Interior Composition Explorer (NICER) is slated for launch to the International Space Station in late 2016. Pasham has identified six potential middle-mass black holes that NICER may be able to explore for similar signals.
For more information, visit:
http://www.nasa.gov/topics/universe/index.html
Related Links:
Paper: "A 400-solar-mass black hole in the M82 galaxy":
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13710.html
Download high-resolution video from NASA Goddard's Science Visualization Studio:
http://svs.gsfc.nasa.gov/vis/a010000/a011600/a011625
The signals have helped astronomers identify an unusual midsize black hole called M82 X-1, which is the brightest X-ray source in a galaxy known as Messier 82. Most black holes formed by dying stars are modestly-sized, measuring up to around 25 times the mass of our sun. And most large galaxies harbor monster, or supermassive, black holes that contain tens of thousands of times more mass.
“Between the two extremes of stellar and supermassive black holes, it's a real desert, with only about half a dozen objects whose inferred masses place them in the middle ground," said Tod Strohmayer, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Explore M82 X-1 and learn
more about how astronomers used X-ray fluctuations to determine its status as an
intermediate-mass black hole.
Image Credit:
NASA Goddard Space Flight
Center
"For reasons that are very hard to understand, these objects have resisted standard measurement techniques," said Richard Mushotzky, a professor of astronomy at UMCP.
By going over past RXTE observations, the astronomers found specific changes in brightness that helped them determine M82 X-1 measures around 400 solar masses.
As gas falls toward a black hole, it heats up and emits X-rays. Variations in X-ray brightness reflect changes occurring in the gas. The most rapid fluctuations happen near the brink of the black hole’s event horizon, the point beyond which nothing, not even light, can escape.
Astronomers call these rhythmic pulses quasi-periodic oscillations, or QPOs. For stellar black holes, astronomers have established that the larger the mass, the slower the QPOs, but they could not be sure what they were seeing from M82 X-1 was an extension of this pattern.
"When we study fluctuations in X-rays from many stellar-mass black holes, we see both slow and fast QPOs, but the fast ones often come in pairs with a specific 3:2 rhythmic relationship," explained Dheeraj Pasham, UMCP graduate student. For every three pulses from one member of a QPO pair, its partner pulses twice.
By analyzing six years of RXTE data, the team located X-ray variations that reliably repeat about 5.1 and 3.3 times a second, a 3:2 relationship. The combined presence of slow QPOs and a faster pair in a 3:2 rhythm sets a standard scale allowing astronomers to extend proven relationships used to determine the masses of stellar-mass black holes.
The results of the study were published online in the Aug. 17 issue of the journal Nature.
Launched in late 1995 and decommissioned in 2012, RXTE is one of NASA's longest-serving astrophysics missions. Its legacy of unique measurements continues to provide researchers with valuable insights into the extreme environments of neutron stars and black holes.
A new NASA X-ray mission called the Neutron Star Interior Composition Explorer (NICER) is slated for launch to the International Space Station in late 2016. Pasham has identified six potential middle-mass black holes that NICER may be able to explore for similar signals.
For more information, visit:
http://www.nasa.gov/topics/universe/index.html
Related Links:
Paper: "A 400-solar-mass black hole in the M82 galaxy":
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13710.html
Download high-resolution video from NASA Goddard's Science Visualization Studio:
http://svs.gsfc.nasa.gov/vis/a010000/a011600/a011625
NASA
Guillermo Gonzalo Sánchez Achutegui
6 comentarios:
La Teoría del Big Bang, o la "Gran Explosión" ya fue confirmada por el Telescopio Espacial Hubble, con un certeza de 13,700 mil millones de años que sucedió, no se descarta mi tesis que Dios mismo se empequeñeció a una mínima parte como un punto de la punta de un alfiler, y concentró tanta energía que originó la Gran Explosión y ésta continua por los siglos.....
Otro tema maravilloso es el BIN BAN .
traumatico,todo eso,es increible, tu tesis no laq habia imaginado
singularidad la llaman
Que misterios hay en este universo infinito.
Nuestra ciencia aún está en pañales, sabemos tan poco de nuestro universo y ni siquiera sabemos si todas las teorías existentes son por lo menos un tanto por ciento verídicas, de lo que sí estoy segura es que la creación es tan perfecta desde su fuente misma de expresión hasta los últimos fractales donde se extiende...Un saludo Guillermo.
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