![]() |
Астронет: Астрономическая картинка дня Очень быстро вращающиеся спиральные галактики http://www.variable-stars.ru/db/msg/1529848/eng |
Credit & Copyright: Top row:
NASA,
ESA,
Hubble,
P. Ogle & J. DePasquale
(STScI);
Bottom row: SDSS, P. Ogle & J. DePasquale (STScI)
Explanation:
Why are these galaxies spinning so fast?
If you estimated each
spiral's mass by how
much light it emits, their fast rotations should
break them apart.
The leading hypothesis as to why these galaxies don't break apart is
dark
matter --
mass so dark we can't see it.
But these galaxies are even out-spinning this break-up limit --
they are the
fastest rotating disk galaxies known.
It is therefore
further hypothesized
that their
dark matter halos are so massive -- and their spins so fast --
that it is harder for them to form stars than
regular spirals.
If so, then these galaxies may be among the
most massive spirals possible.
Further study of surprising super-spirals like these will continue,
likely including observations taken by
NASA's
James Webb Space Telescope
scheduled for launch in 2021.
Bottom row: SDSS, P. Ogle & J. DePasquale (STScI)
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.