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Астронет: Астрономическая картинка дня Неожиданное рентгеновское излучение из скопления галактик в Персее http://variable-stars.ru/db/msg/1395615/eng |
Credit & Copyright: X-ray: NASA/CXO/Oxford University/J. Conlon et al.;
Radio: NRAO/AUI/NSF/Univ. of Montreal/Gendron-Marsolais et al.;
Optical: NASA/ESA/IoA/A. Fabian et al.; DSS
Explanation:
Why does the Perseus galaxy cluster shine so strangely in one specific color of X-rays?
No one is sure, but a much-debated hypothesis holds that these
X-rays
are a clue to the long-sought identity of
dark matter.
At the center of this mystery is a 3.5
Kilo-electronvolt
(KeV) X-ray color that appears to glow excessively only when regions well outside
the cluster center are observed,
whereas the area directly surrounding a likely central
supermassive black hole is
actually deficient in 3.5 KeV X-rays.
One
proposed resolution
-- quite controversial --
is that something never seen before might be present:
florescent dark matter (FDM).
This form of
particle dark matter might be able to absorb 3.5 KeV X-radiation.
If operating, FDM, after absorption,
might later emit these X-rays from all over the cluster, creating an
emission line.
However, when seen
superposed
in front of the central region
surrounding the black hole,
FDM's absorption would be more prominent, creating an
absorption line.
Pictured, a composite image of the
Perseus galaxy cluster shows visible and radio light
in red, and
X-ray light from the Earth-orbiting
Chandra Observatory in blue.
Free APOD Lectures:
January 5 in NYC & January 9 in DC
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
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rights apply.
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LHEA at
NASA /
GSFC
& Michigan Tech. U.