On the Formation of Galactic Warps and Spiral Arms
碩士 === 國立中央大學 === 天文研究所 === 91 === The warping of galactic discs is a general phenomenon for disc galaxies and it has been an important subject for four decades since its first discovery. Sparke (2002)gives an argument showing that the warps are a gravitational phenomenon. We thus fo...
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| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2003
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| Online Access: | http://ndltd.ncl.edu.tw/handle/93944066411691423116 |
| Summary: | 碩士 === 國立中央大學 === 天文研究所 === 91 ===
The warping of galactic discs is a general
phenomenon for disc galaxies
and it has been an important subject for four decades since its
first discovery.
Sparke (2002)gives an argument
showing that the warps are a gravitational phenomenon.
We thus follow this line and focus on the gravity here,
and we wish to further explore the parameter spaces
for the model proposed by Jiang & Binney (1999).
We try
different types
of cosmic infall with different total mass and
also study the effect of disc accretion.
Then we study the relation between warps and spiral arms.
We find that the mass accretion along the galactic plane is not
helpful for the formation of warps but could be a good way to produce
halo stars and high velocity clouds.
On the other hand, all three types of cosmic infall we introduce
could produce warps with different amplitudes and shapes at different time.
These results reconfirm that warps is a halo phenomenon and
closely related to the tilted non-axisymmetric
component of halo.
Warps and spiral arms are projections on different two-dimensional plane of the same non-axisymmetric structure in three-dimensional space.
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