Re: Dark Matter / Energy

OG <owen@xxxxxxxxxxxxxxxxxxx> wrote:
...

As far as Dark Matter is concerned, there is good evidence to suggest that
this is evenly distributed through and around the galaxy - hence there is
no concentration within the solar system to affect the Earth's orbit around
the Sun. However as the Dark Matter is centred on the Galaxy centre, it does
affect the orbit of the Sun (and other stars) around the centre of the
Galaxy.

In the case of the dwarf galaxies surrounding the Milk Way, a team led
by Gerry Gilmore of the Institute of Astronomy at Cambridge reported on
3 February that "they all had a core of dark matter of a uniform size
and temperature--somewhat warmer than the most popular theories of dark
matter predict." Gilmore said that this could represent "an intrinsic
property of dark matter."

/Science/ reports "the Cambridge team says it has found a uniform
volume of dark matter in each galaxy, about 1000 light-years across and
with a density equivalent to four hydrogen atoms per cubic centimeter."

The notion that dark matter may be found in a uniform "ball" (for want
of a better word) of a certain size, located at the core of at least
some galaxies and not spread uniformly throughout the galaxies, is
quite revolutionary. If this applies to a large spiral like the Milky
Way, it means that the center of the galaxy is not only the center of
mass of the dark matter, but is the actual location of the dark matter.

The mass of the dark matter would have to be quite finely tuned to
ensure that, on the one hand, it was sufficient to prevent the galaxy
from flying apart due to inertial forces, and, on the other hand, the
dark matter itself did not contract and end up being eaten by the
galaxy's central black hole(s). Is this one for the Anthropic
Principle?

This research has not been published yet, but is available at various
sites on-line, including the BBC.

Davoud

Atheist? Then how do you explain Usenet, God's own Little Garden of
Psychopaths?

--
usenet *at* davidillig dawt com
.

Relevant Pages

  • Re: Dark Matter / Energy
    ... However as the Dark Matter is centred on the Galaxy centre, ... affect the orbit of the Sun around the centre of the ... February that "they all had a core of dark matter of a uniform size ... (gravitational energy excepted, I assume!). ...
    (sci.astro.amateur)
  • Re: The way the blackhole works (Windcupters in the Matrix)
    ... Spiral arms trap flows of dark matter and direct ... more concentrated amounts toward the center of the galaxy. ... But one thing happens when a solar object runs into an event horizon: ... It is a place where dark matter turns into electrons and further ...
    (sci.astro)
  • Re: dark matter question
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    (sci.astro)
  • Re: dark matter question
    ... leave the galaxy, so the milky way's dark matter isn't neutrinos. ... If a particle of dark matter passes a star, ... If dark matter particles are light, oh, lighter than Jupiter, this ...
    (sci.astro)
  • Re: dark matter question
    ... leave the galaxy, so the milky way's dark matter isn't neutrinos. ... you could think of the star and the dark matter particle ... particles speeds much greater than the stars. ...
    (sci.astro)