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inclination angle and redshift. Produce images at 5 different inclinations
including face-on (incl=0) and near edge on (incl=85). Save and
print those images.
b. What happens to the double horn profile in the unresolved spectra as the
galaxy is more an more inclined? Consider how Tully-Fisher method of
estimating a galaxy’s luminosity requires us to estimate the maximum HI
rotation velocity. How is the measurability of quantity affected by the
inclination of the galaxy?
c. Now consider the resolved HI velocity field, which shows what a VLA
might see when looking at this field. The lines are velocity contours.
Describe what happens to the velocity contours in the resolved 2-D image
as the galaxy becomes more and more inclined? 6. [C&O 25.20] According to the virial theorem, the central radial-velocity
dispersion is related to the mass and size of the galaxy by σ r2 ∝ M / R (see Eq.
25.13). Use arguments similar to those for the Tully-Fisher relation to show that
L ∝ σ r4 , which is the Faber-Jackson relation, Eq. (25.40). – Page 4 of 4 –...
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This document was uploaded on 03/04/2014 for the course ASTROPHYS 362 at Minnesota State University Moorhead .
- Spring '14