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Астронет: Астрономическая картинка дня Дело скопления Пуля: озвучено http://www.variable-stars.ru/db/msg/1712443/eng |
Credit & Copyright: X-ray: NASA/CXC/SAO; Optical: NASA/STScI, Magellan/U.Arizona; Lensing Map: NASA/STScI,
ESO WFI, Magellan/U.Arizona; Sonification: NASA/CXC/SAO/K.Arcand, SYSTEM Sounds (M.
Russo, A. Santaguida)
Explanation:
What's the matter with the Bullet Cluster?
This massive cluster of galaxies
(1E 0657-558)
creates
gravitational lens distortions
of background galaxies in a way that has been interpreted
as strong evidence for the leading theory: that
dark matter exists within.
Different analyses, though, indicate that a less popular alternative -- modifying
gravity-- could explain cluster dynamics without
dark
matter, and provide a
more likely progenitor scenario as well.
Currently, the
two scientific hypotheses are competing to explain the observations: it's
invisible matter
versus amended gravity.
The duel is dramatic as a clear
Bullet-proof example
of dark matter would shatter the simplicity of
modified gravity theories.
The featured sonified image
is a
Hubble/Chandra/Magellan
composite with red depicting the X-rays emitted by hot gas, and blue depicting the
suggested
separated dark matter distribution.
The sonification assigns low tones to dark matter, mid-range frequencies to
visible light, and high
tones to
X-rays.
The battle over the
matter in the Bullet cluster is likely to continue as more
observations, computer simulations, and analyses are completed.
Submitted to APOD:
Notable images of the 2020 Geminids Meteor Shower
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.