Credit X-ray: NASA/CXC/UNH/D.Lin et al, Optical: NASA/ESA/STSc
A team of researchers using data from ESA's XMM-Newton X-ray space observatory, NASA's Chandra X-ray Observatory and NASA's Swift X-Ray Telescope has found evidence for the existence of an intermediate-mass black hole (IMBH).
Scientists have strong evidence for the existence of stellar black holes, which are typically five to 30 times as massive as the Sun. They have also discovered that supermassive black holes
with masses as large as billions of Suns exist in the centers of most
galaxies. They have long been searching for IMBHs that would exist in
between these two extremes, which would contain thousands of solar
masses. Thought to be seeds that will eventually grow to become
supermassive, IMBHs are especially elusive, and thus very few robust
candidates have ever been found.
One of the few methods scientists can use to try to find an IMBH is
to wait for a star to pass close to it and become disrupted. This event
causes the black hole to emit a flare that can be observed by telescopes
like Chandra. Previously, this kind of event has only been clearly seen
at the center of a galaxy before, not at the outer edges.
In this new study led by Dacheng Lin of the University of New
Hampshire, scientists identified a possible IMBH in observations of a
large galaxy some 740 million light years away.
XMM-Newton Images of 6dFGS gJ215022.2-055059
X-ray data from XMM-Newton over two epochs shows how the candidate IMBH brightens over time. Credit: ESA/XMM-Newton/D.Lin et al.
Given this and other observed properties, the researchers concluded that this X-ray
source represents a star that was disrupted and torn apart by a black
hole with a mass of around fifty thousand times that of the Sun. Such
star-triggered outbursts are expected to only happen rarely from this
type of black hole, so this discovery suggests that there could be many
more such black holes lurking in a dormant state in galaxy peripheries
across the local Universe.
In addition to telescopes mentioned above, this study, which appears online in Nature Astronomy on June 18, 2018 (and available here),
used data from the Canada-France-Hawaii Telescope, the NASA/ESA Hubble
Space Telescope, NAOJ's Subaru Telescope, the Southern Astrophysical
Research (SOAR) Telescope, and the Gemini Observatory.
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.
Source: NASA’s Chandra X-ray Observatory
Fast Facts for J2150:
Scale: About 36 arcsec across (129,000 light years)
Category: Black Holes
Coordinates (J2000): RA 21h 50m 22.5s | Dec -5° 51´ 08.2"
Constellation: Aquarius
Observation Date: September 14, 2016
Observation Time: 21 hours 25 minutes
Obs. ID: 17862
Instrument: ACIS
References: D. Lin et al., "A Luminous X-ray Outburst From an Intermediate-mass Black Hole In An Off-centre Star Cluster", Nature (sub, 14, Jun 2018). arXiv:1806.05692
Color Code: X-ray: Purple; Optical: Gold
Distance Estimate: About 740 million light years
