Cygnus A
Credit: X-ray: NASA/CXC/Columbia Univ./A. Johnson et al.; Optical: NASA/STScI
A ricocheting jet blasting from a giant black hole has been captured by NASA's Chandra X-ray Observatory, as reported in our latest press release. In this composite image of Cygnus A, X-rays
from Chandra (red, green, and blue that represent low, medium and high
energy X-rays) are combined with an optical view from the Hubble Space
Telescope of the galaxies and stars in the same field of view.
Chandra's data reveal the presence of powerful jets of particles and electromagnetic energy
that have shot out from the black hole. The jet on the left has
slammed into a wall of hot gas, then ricocheted to punch a hole in a
cloud of energetic particles, before it collides with another part of
the gas wall.
A labeled version outlines the key features described above. The main figure shows the location of the supermassive black hole,
the jets, the point that the jet on the left ricocheted off a wall of
intergalactic gas ("hotspot E"), and the point where the jet then
struck the intergalactic gas a second time ("hotspot D"). The inset
contains a close-up view of the hotspots on the left and the hole
punched by the rebounding jet, which surrounds hotspot E. The image in
the inset combines X-rays from all three energy ranges to give the
greatest sensitivity to show fine structures such as the hole.
The hole is visible because the path of the rebounding jet between
hotspots E and D is almost directly along the line of sight to Earth, as
shown by the schematic figure depicting the view of Cygnus A from
above. A similar rebounding of the jet likely occurred between hotspots
A and B but the hole is not visible because the path is not along the
Earth's line of sight.
Schematic Views of Cygnus A
The hole is visible because the path of the rebounding jet between
hotspots E and D is almost directly along the line of sight to Earth, as
shown by the schematic figure depicting the view of Cygnus A from
above. A similar rebounding of the jet likely occurred between hotspots A
and B but the hole is not visible because the path is not along the
Earth's line of sight.
(Credit: NASA/CXC/M.Weiss)
Cygnus A is a large galaxy that sits in the middle of a cluster of galaxies about 760 million light years
from Earth. A supermassive black hole at the center of Cygnus A is
rapidly growing as it pulls material swirling around it into its
gravitational grasp. During this process, some of this material is
redirected away from the black hole in the form of narrow beams, or
jets. Such jets can significantly affect how the galaxy and its
surroundings evolve.
In a deep observation that lasted 23 days, scientists used Chandra
to create a highly detailed map of both the jets and the intergalactic
gas, which they used to track the path of the jets from the black hole.
The jet on the left expanded after ricocheting and created a hole in
the surrounding cloud of particles that is between 50,000 and 100,000
light years deep and only 26,000 light years wide. For context, the
Earth is located about 26,000 light years away from the center of the
Milky Way galaxy.
The scientists are working to determine what forms of energy — kinetic energy,
heat or radiation — the jet carries. The composition of the jet and
the types of energy determine how the jet behaves when it ricochets,
such as the size of the hole it creates. Theoretical models of the jet
and its interactions with surrounding gas are needed to make
conclusions about the jet's properties.
Energy produced by jets from black holes can heat intergalactic gas
in galaxy clusters and prevent it from cooling and forming large
numbers of stars in a central galaxy like Cygnus A. Thus, studying
Cygnus A can tell scientists more about how jets from black holes
interact with their surroundings.
These results were presented at the 233rd meeting of the American
Astronomical Society meeting in Seattle, WA, in a study led by Amalya
Johnson of Columbia University in New York. NASA's Marshall Space
Flight Center in Huntsville, Alabama, manages the Chandra program for
NASA's Science Mission Directorate in Washington. The Smithsonian
Astrophysical Observatory in Cambridge, Massachusetts, controls
Chandra's science and flight operations.
Fast Facts for Cygnus A:
Scale: Image is 2.5 arcmin across. (About 540,000 light years across.)
Category: Quasars & Active Galaxies
Coordinates (J2000): RA 19h 59m 28.30s | Dec +40° 44' 02.00"
Constellation: Cygnus
Observation Date: July 16, 2016 - May 21, 2017
Observation Time: 541 hours 11 min (22 days, 13 hours, 11 minutes)
Obs. ID: 5830,5831,6225,6226,6228,6229,6250,6252,17133-17144,17507-17517
Instrument: ACIS
References: Johnson, A. et al, AAS, 233, 6-9 January 2019
Color Code: X-ray: purple. Optical: red, green, and blue
Distance Estimate: About 760 million light years
Source: NASA’s Chandra X-ray Observatory
