J140737.17+442856.2 and J122104.98+113752.3
Credit X-ray: NASA/CXC/Univ. of Victoria/S.Ellison et al.; Optical: SDSS (J140737)
Credit X-ray: NASA/CXC/George Mason Univ./S.Satyapal et al.; Optical: SDSS (J122104)
This graphic shows two of five new pairs of supermassive black holes recently identified by astronomers using a combination of data from NASA's Chandra X-ray Observatory,
the Wide-Field Infrared Sky Explorer Survey (WISE), the ground-based
Large Binocular Telescope in Arizona, and the Sloan Digital Sky Survey
(SDSS) Mapping Nearby Galaxies at APO (MaNGA) survey. This discovery
could help astronomers better understand how giant black holes grow and
how they may produce the strongest gravitational wave signals in the Universe, as described in our press release.
Each pair contains two supermassive black holes weighing millions of
times the mass of the Sun. These black hole couples formed when two
galaxies collided and merged with each other, forcing their supermassive
black holes close together. While theoretical models have predicted
such giant growing black hole pairings should be relatively abundant,
they have been difficult to find.
Illustration of Dual Supermassive Black Holes
This illustration depicts two centrally located supermassive black holes
surrounded by disks of hot gas. The black holes orbit each other for
hundreds of millions of years before they merge to form a single
supermassive black hole that sends out intense gravitational waves. Illustration: NASA/CXC/A.Hobart
To uncover these latest supermassive black hole pairs, astronomers
used optical data from the Sloan Digital Sky Survey (SDSS) — shown in
the main panel of each image — to identify galaxies where it appeared
that a merger between two smaller galaxies was underway. Next, they
selected objects where the separation between the centers of the two
galaxies in the SDSS data is less than 30,000 light years, and the infrared colors from WISE data match those predicted for a rapidly growing supermassive black hole.
Seven merging systems containing at least one supermassive black hole were found with this technique. Because strong X-ray emission
is a hallmark of growing supermassive black holes, the team then
observed these systems with Chandra. They found that five systems
contained pairs of X-ray sources that were separated by a relatively
small distance (see inset for two examples), providing compelling
evidence that they contain two growing, or feeding, supermassive black
holes.
Both the X-ray data from Chandra and the infrared WISE observations
suggest that the supermassive black holes are buried in large amounts of
dust and gas. Because these two wavelengths are able to penetrate the
obscuring clouds, this makes the combination of infrared selection with
X-ray follow-up a very effective way to find these black hole pairs.
Chandra's sharp vision is also critical as it is able to resolve each of
the X-ray sources in the pairs.
Four of the dual black hole candidates were reported in a paper by
Satyapal et al. that was recently accepted for publication in The
Astrophysical Journal, and appears online.
The other dual black hole candidate was reported in a paper by Ellison
et al., which was published in the September 2017 issue of the Monthly
Notices of the Royal Astronomical Society and appears online.
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 J140737:
Scale: Image is 3 arcmin (~1.5 million light years) wide
Category: Quasars & Active Galaxies, Black Holes
Coordinates (J2000): RA 14h 07m 37.17s | Dec 44° 28´ 56.2"
Constellation: Boötes
Observation Date: 1 pointing in February 2017
Observation Time: 8 hours 15 min
Obs. ID: 19990
Instrument: ACIS
References: Ellison, S. et al., 2017, MNRAS, 470, L49, arXiv:1705.05465
Color Code: X-ray (Blue), Optical (Red, Green, Blue)
Distance Estimate: About 1.8 billion light years (z=0.14)
Fast Facts for J122104:
Scale: Image is 3 arcmin (~760,000 light years) wide.
Category: Quasars & Active Galaxies, Black Holes
Coordinates (J2000): RA 12h 21m 04.98s | Dec +11° 37´ 52.3"
Constellation: Virgo
Observation Date: 1 pointing in July 2014
Observation Time: 1 hour 2 min
Obs. ID: 16073
Instrument: ACIS
References: Satyapal, S et al., 2017, ApJ (in press), arXiv:1707.03921
Color Code: X-ray (Blue), Optical (Red, Green, Blue)
Distance Estimate: About 910 million light years (z=0.068)
Source: NASA’s Chandra X-ray Observatory
