The
spiral galaxy NGC 3627 is located about 30 million light years from
Earth. This composite image includes X-ray data from NASA's Chandra
X-ray Observatory (blue), infrared data from the Spitzer Space Telescope
(red), and optical data from the Hubble Space Telescope and the Very
Large Telescope (yellow). The inset shows the central region, which
contains a bright X-ray source that is likely powered by material
falling onto a supermassive black hole.
A search using archival
data from previous Chandra observations of a sample of 62 nearby
galaxies has shown that 37 of the galaxies, including NGC 3627, contain
X-ray sources in their centers. Most of these sources are likely powered
by central supermassive black holes. The survey, which also used data
from the Spitzer Infrared Nearby Galaxy Survey, found that seven of the
37 sources are new supermassive black hole candidates.
Confirming previous Chandra results, this study finds the fraction of
galaxies found to be hosting supermassive black holes is much higher
than found with optical searches. This shows the ability of X-ray
observations to find black holes in galaxies where relatively low-level
black hole activity has either been hidden by obscuring material or
washed out by the bright optical light of the galaxy.
Credits: NASA/CXC/Ohio State Univ./C.Grier et al.; Optical: NASA/STScI, ESO/WFI; Infrared: NASA/JPL-Caltech
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