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Астронет: Астрономическая картинка дня Множество сингулярностей в центре Галактики http://variable-stars.ru/db/msg/1409793/eng |
Credit & Copyright: NASA/CXC /
Columbia Univ./
C. Hailey et al.
Explanation:
A recent informal poll found that astronomers don't yet have a good
collective
noun for a group of black holes,
but they need one.
The red circles in this
Chandra
Observatory X-ray image
identify a group of a dozen black holes that
are members of binary star systems.
With 5 to 30 times the mass of the Sun, the black hole binaries
are swarming within about 3 light-years of
the center of our galaxy
where the supermassive black hole identified as Sagittarius A* (Sgr A*)
resides.
Yellow circles indicate
X-ray sources that are likely less massive
neutron stars or white dwarf stars in binary star systems.
Alone, black holes
would be invisible, but as part of a
binary star system they accrete material from their
normal companion star and generate X-rays.
At the distance of the galactic center
Chandra can detect only the brighter of these black hole binary systems
as point-like sources of X-rays,
hinting that many fainter X-ray emitting black hole binaries
should exist there,
as yet undetected.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.