MILKY WAY SPIRAL
In
every ancient culture The Great Mother Goddess in Heaven was worshipped
as showed here with the Egyptian picture 2 where you can see how life
matter is formed and radiated out from her womb. The animated star atlas
picture shows the centre in our Galaxy.
The
most common explanations of animal rock carvings having some drawings
"inside" the body, are that the drawings are showing intestines which
also can be the fact in some cases, but in many cases the interpreters are forgetting
that there is mythological stories to tell when they are looking on the old
rock carvings.
Picture
1 below with a crossed square on the back of the reindeer, marking the Galaxy centre, are from
Norway. Picture 2 are a star map marking the Galaxy centre with a red/blue swirl. Picture 3 are from Turkey
showing the centre whit concentric rings and a dot.
Looking
from our Sun system, the direction towards our Galaxy centre are placed in the star constellation of
Sagittarius, here marked in the star map picture 2 with the red/blue swirl. Now if you think about the fact that the
southern Milky Way contours was mythological interpreted both as a Woman and a
Cow, you can se the resemblance between the pictures above and below.
Celtic art showing Universal creation patterns.
Bronze Age artefact from Finland illustrating the swirling force in
Creation. Compare to my drawing to the right, the artefact are very
likely to show the Solar System position in our Galaxy, The Milky Way.
Barred spiral galaxy
http://en.wikipedia.org/wiki/Barred_spiral_galaxy#The_bars
NGC 1300, viewed nearly
face-on.
Hubble Space Telescope image.
The
Sculptor Galaxy, a barred spiral starburst galaxy, (2MASS).
A barred spiral galaxy is a
spiral galaxy with a central bar-shaped structure composed of
stars. Bars are found in approximately half of all spiral galaxies[1].
Bars generally affect both the motions of stars and
interstellar gas within spiral galaxies and can affect
spiral arms as well[1].
Edwin Hubble classified these
types of spiral galaxies as "SB" ("Spiral", "Barred") in his
Hubble sequence, and arranged them into three sub-categories based
on how open the arms of the spiral are. SBa types feature tightly bound
arms, while SBc types are at the other extreme and have loosely bound
arms. SBb type galaxies lie in between. A fourth type, SBm, was
subsequently created to describe somewhat
irregular barred spirals, such as the
Magellanic Cloud galaxies, which were once classified as irregular
galaxies, but have since been found to contain barred spiral structures.
In
2005, observations by the
Spitzer Space Telescope backed up previously collected evidence that
suggested the
Milky Way is a barred spiral galaxy. Observations by
radio telescopes had for years suggested our galaxy to be barred,
but
Spitzer's vision in the
infrared region of the spectrum has provided a more definite
calculation.
The
bars
Barred spiral galaxies are relatively common, with
surveys showing that up to two-thirds of all spiral galaxies contain a
bar.[2]
The current
hypothesis is that the bar structure acts as a type of
stellar nursery, fueling
star birth at their centers. The bar is thought to act as a
mechanism that channels
gas inwards from the spiral arms through
orbital resonance, in effect funneling the flow to create new stars.[3]
This process is also thought to explain why many barred spiral galaxies
have
active galactic nuclei, such as that seen in the
Southern Pinwheel Galaxy.
The creation of the bar is generally thought to be the
result of a density wave radiating from the center of the galaxy whose
effects reshape the orbits of the inner stars. This effect builds over
time to stars orbiting further out, which creates a self-perpetuating
bar structure.[4]
Another possible cause of bar creation is gravitational disruptions
between galaxies.[citation
needed]
Bars are thought to be a temporary phenomenon in the life
of spiral galaxies, the bar structure decaying over time, transforming
the galaxy from a barred spiral to a "regular" spiral pattern. Past a
certain size the accumulated mass of the bar compromises the stability
of the overall bar structure. Barred spiral galaxies with high mass
accumulated in their center tend to have short, stubby bars.
[5] Since so many spiral galaxies have a bar structure, it is
likely that it is a recurring phenomenon in spiral galaxy development.
The oscillating evolutionary cycle from spiral galaxy to barred spiral
galaxy is thought to take on the average about two billion years.[6]
Recent studies have confirmed the idea that bars are a
sign of galaxies reaching full maturity as the "formative years" end. A
team led by Kartik Sheth of the Spitzer Science Center at the California
Institute of Technology in Pasadena discovered that only 20 percent of
the spiral galaxies in the distant past possessed bars, compared with
nearly 70 percent of their modern counterparts.[7]
The
bulges
Studying the core of the Milky Way, scientists found out
that the Milky Way's
bulge was peanut-shaped. This led to the conclusion that all barred
spiral galaxies have a peanut shaped bulge. When observing a distant
spiral galaxy with a rotational axis perpendicular to the line of sight,
or one that appears "edge-on" to the observer, the shape of the bulge
can be easily observed, and therefore quickly classified as either a
barred spiral or a regular spiral. Galaxy
NGC 4565 has been classified as an unbarred spiral galaxy using this
method.[citation
needed]
Examples
See
also
References
-
^
a
b D. Mihalas (1968).
Galactic
Astronomy. W. H. Freeman.
ISBN 9780716703266.
-
^ P. B. Eskridge, J. A. Frogel
(1999). "What
is the True Fraction of Barred Spiral Galaxies?". Astrophysics and Space Science
269/270: 427–430.
doi:10.1023/A:1017025820201.
http://adsabs.harvard.edu/abs/1999Ap&SS.269..427E.
-
^ J. H. Knapen, D. Pérez-Ramírez, S.
Laine (2002). "Circumnuclear
regions in barred spiral galaxies - II. Relations to host galaxies".
Monthly Notice of the Royal Astronomical Society
337
(3): 808–828.
doi:10.1046/j.1365-8711.2002.05840.x.
http://adsabs.harvard.edu/abs/2002MNRAS.337..808K.
-
^ F. Bournaud, F. Combes (2002). "Gas
accretion on spiral galaxies: Bar formation and renewal".
Astronomy and Astrophysics 392: 83–102.
doi:10.1051/0004-6361:20020920.
http://adsabs.harvard.edu/abs/2002A&A...392...83B.
-
^
Barred Spirals Come and Go,
Sky and Telescope, April 2002
-
^
Ripples in a Galactic Pond,
Scientific American, October 2005
-
^
Barred Spiral Galaxies are Latecomers to the Universe Newswise,
Retrieved on
July 29,
2008.
External links
Retrieved from "http://en.wikipedia.org/wiki/Barred_spiral_galaxy"
Categories:
Barred spiral galaxies |
Spiral galaxies |
Barred galaxies |
Galaxy morphological types
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MILKY WAY
MYTHOLOGY - THE ORIGIN OF GLOBAL CREATION STORIES
