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Paper: |
The Galactic Structure and Stellar Population in the CFHTLS Wide Fields |
Volume: |
446, Galaxy Evolution: Infrared to Millimeter Wavelength Perspective |
Page: |
169 |
Authors: |
Xiao, Q. B.; Shu, C. G.; Luo, Z. J.; Shao, Z. Y.; Shen, S. Y. |
Abstract: |
Using the star counts from the CFHTLS (Canada-France-Hawaii Telescope Legacy Survey) release T0005, we individually
investigate the Milky Way structure in each of the four wide fields. Both for the thin- and thick-disk, we adopt a
double exponential model and fit the stars with g'–r'
> 1.0 to determine their scale heights. The best-fittings give a similar thin-disk model of
the scale heights H1∼220 pc in all fields. The scale heights of the thick-disk are about 700 pc in all fields.
The local space number density normalization of the thick-disk is 6.2% – 11.9% of the thin disk. Given the binary
fraction ƒm = 35%, the corrected scale heights of the thin- and thick-disk and the thick-to-thin disk density
normalization is 260 pc, 860 pc and 10%, respectively. For the halo, the stellar density distribution is modeled as a
power law. We fixed the disk parameters and estimate the structure of stellar halo based on all stars in each wide
field. The results give a sharp (large power index: n>2.8) and round (large axial ratio: c/a
> 0.8) halo. We find that it is difficulty to well constrain the stellar halo by a single power law, and a “dual-halo” model is
needed to describe the density distribution of the stellar halo. |
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