A black hole has blasted out a surprisingly powerful
jet in the distant universe, according to a study from NASA’s Chandra X-ray
Observatory.
X-ray: NASA/CXC/CfA/J. Maithil et al.; Illustration:
NASA/CXC/SAO/M. Weiss; Image Processing: NASA/CXC/SAO/N. Wolk
A black
hole has
blasted out a surprisingly powerful jet in the distant universe, according to a new
study from NASA’s Chandra X-ray Observatory and discussed in our latest press release. This jet exists early enough in the cosmos that it is being illuminated
by the leftover glow from the big
bang itself.
Astronomers used Chandra and the
Karl G. Jansky Very Large Array (VLA) to study this black hole and its jet at a
period they call “cosmic noon,” which occurred about three billion years after
the universe began. During this time most galaxies and supermassive
black holes were growing faster than at any other time during the history of the
universe.
The main graphic is an artist’s
illustration showing material in a disk that is falling towards a supermassive
black hole. A jet is blasting away from the black hole towards the upper right,
as Chandra detected in the new study. The black hole is located 11.6
billion light-years from Earth when the cosmic
microwave background (CMB), the leftover glow from the big bang, was much denser than it
is now. As the electrons in the jets fly away from the black hole, they
move through the sea of CMB radiation and collide with microwave photons. These collisions boost the energy of the photons up
into the X-ray
band (purple
and white), allowing them to be detected by Chandra even at this great
distance, which is shown in the inset.
Researchers, in fact, identified
and then confirmed the existence of two different black holes with jets over
300,000 light-years long. The two black holes are 11.6 billion and 11.7 billion
light-years away from Earth, respectively. Particles in one jet are moving at
between 95% and 99% of the speed
of light (called
J1405+0415) and in the other at between 92% and 98% of the speed of light
(J1610+1811). The jet from J1610+1811 is remarkably powerful, carrying roughly
half as much energy as the intense light from hot gas orbiting the black hole.
The team was able to detect these
jets despite their great distances and small separation from the bright,
growing supermassive black holes — known as “quasars” — because of Chandra’s sharp X-ray vision, and
because the CMB was much denser then than it is now, enhancing the energy boost
described above.
When quasar jets approach the speed
of light, Einstein’s theory of special
relativity creates a dramatic brightening effect. Jets aimed toward Earth appear
much brighter than those pointed away. The same brightness astronomers observe
can come from vastly different combinations of speed and viewing angle. A jet
racing at near-light speed but angled away from us can appear just as bright as
a slower jet pointed directly at Earth.
The researchers developed a novel
statistical method that finally cracked this challenge of separating effects of
speed and of viewing angle. Their approach recognizes a fundamental bias:
astronomers are more likely to discover jets pointed toward Earth simply
because relativistic effects make them appear brightest. They incorporated this
bias using a modified probability distribution, which accounts for how jets
oriented at different angles are detected in surveys.
Their method works by first using
the physics of how jet particles scatter the CMB to determine the relationship
between jet speed and viewing angle. Then, instead of assuming all angles are
equally likely, they apply the relativistic selection effect: jets beamed
toward us (smaller angles) are overrepresented in our catalogs. By running ten
thousand simulations that match this biased distribution to their physical
model, they could finally determine the most probable viewing angles: about 9
degrees for J1405+0415 and 11 degrees for J1610+1811.
These results were presented by
Jaya Maithil (Center for Astrophysics | Harvard & Smithsonian) at the 246th
meeting of the American Astronomical Society in Anchorage, AK, and are also
being published in The Astrophysical Journal. A preprint is available here. NASA’s Marshall Space Flight Center in Huntsville,
Alabama, manages the Chandra program. The Smithsonian Astrophysical
Observatory’s Chandra X-ray Center controls science operations from Cambridge,
Massachusetts, and flight operations from Burlington, Massachusetts.
Visual Description
This release is supported by an artist’s
illustration of a jet blasting away from a supermassive black hole.
The black hole sits near the center of
the illustration. It resembles a black marble with a fine yellow outline.
Surrounding the black hole is a swirling disk, resembling a dinner plate tilted
to face our upper right. This disk comprises concentric rings of fiery swirls,
dark orange near the outer edge, and bright yellow near the core.
Shooting out of the black hole are two
streaky beams of silver and pale violet. One bright beam shoots up toward our
upper right, and a second somewhat dimmer beam shoots in the opposite
direction, down toward our lower left. These beams are encircled by long, fine,
corkscrewing lines that resemble stretched springs.
This black hole is located 11.6 billion
light-years from Earth, much earlier in the history of the universe. Near this
black hole, the leftover glow from the big bang, known as the cosmic microwave
background or CMB, is much denser than it is now. As the electrons in the jets
blast away from the black hole, they move through the sea of CMB radiation. The
electrons boost the energies of the CMB light into the X-ray band, allowing the
jets to be detected by Chandra, even at this great distance.
Inset at our upper righthand corner is an X-ray image depicting this interaction. Here, a bright white circle is ringed with a band of glowing purple energy. The jet is the faint purple line shooting off that ring, aimed toward our upper right, with a blob of purple energy at its tip.
Source: NASA's Chandra Sees Surprisingly Strong Black Hole Jet at Cosmic "Noon" - NASA
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