Credit X-ray: NASA/CXC/Univ. of Washington/T.Dorn-Wallenstein et al.;
Optical: NASA/ESA/J. Dalcanton, et al. & R. Gendler
Optical: NASA/ESA/J. Dalcanton, et al. & R. Gendler
An intriguing source has been discovered in the nearby Andromeda galaxy using data from NASA's Chandra X-ray Observatory
and ground-based optical telescopes. Previously thought to be part of
the Milky Way's neighbor galaxy, the new research shows this source is
actually a very distant object 2.6 billion light years away that is
acting as a cosmic bomb, as reported in our press release.
This graphic shows the Chandra data (blue in inset) of the source
known as LGGS J004527.30+413254.3 (J0045+41 for short) in the context of
optical
images of Andromeda from the Hubble Space Telescope. In the inset
image, north is up and in the large image north is to the lower right.
Andromeda, also known as M31, is a spiral galaxy located about 2.5
million light years from Earth.
Even more intriguing than the large distance of J0045+41 is that it likely contains a pair of giant black holes
in close orbit around each other. The estimated total mass for these
two supermassive black holes is about two hundred million times that of
our Sun.
J0045+41 was previously classified as a different type of object — a
pair of orbiting stars — when it was thought to occupy Andromeda. A team
of researchers combined the Chandra X-ray data with spectra from the
Gemini North telescope in Hawaii, providing evidence that J0045+41
contained at least one supermassive black hole. Using data from the
Palomar Transient Factory telescopes in California, the team found
repeating variations in the light from J0045+41, a pointer to the
presence of two orbiting giant black holes.
The researchers estimate that the two putative black holes orbit each
other with a separation of only a few hundred times the distance
between the Earth and the Sun. This corresponds to less than one
hundredth of a light year. By comparison, the nearest star to our Sun is
about four light years away.
Such a system could be formed as a consequence of the merger,
billions of years earlier, of two galaxies that each contained a
supermassive black hole. At their current close separation, the two
black holes are inevitably being drawn closer together as they emit gravitational waves.
A paper describing this result was accepted for publication in The Astrophysical Journal and a preprint is available 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 J0045+41:
Scale: Full image is 1 degree across. Inset is 15 arcsec across (172 light years)
Category: Quasars & Active Galaxies, Black Holes
Observation Date: October 19, 2015
Observation Time: 13 hours 43 minutes
Obs. ID: 17010
Instrument: ACIS
References: Dorn-Wallenstein, et al., 2017, ApJ, 850, 86; arXiv:1704.08694
Color Code: X-ray (Blue), Optical (red, green, blue)
Distance Estimate: About 2.6 billion light years (z=0.215)
Source: NASA’s Chandra X-ray Observatory
