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Structure and Kinematics at the North Galactic Pole

Published online by Cambridge University Press:  07 August 2017

S. R. Majewski*
Affiliation:
The Observatories of the Carnegie Institution of Washington 813 Santa Barbara Street Pasadena, CA 91101 U.S.A.

Abstract

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Results from a complete survey of proper motions to B = 22.5 at the North Galactic Pole are summarized. Evidence from this and other surveys indicates that (1) the thick disk may extend to as much as 5.5 kpc above the Galactic plane at the solar radius, and (2) the thick disk may contain stars with metallicities as low as [Fe/H] = −1.6 or lower. These two properties of the thick disk mean that surveys of halo stars risk serious contamination by thick disk stars unless very conservative selection criteria are used. Applying these conservative selection criteria to existing surveys of halo stars reveals a surprising result - namely, that the halo is in retrograde rotation.

Type
I. The Stellar Populations in the Milky Way
Copyright
Copyright © Kluwer 

References

Allen, C., Schuster, W. J. & Poveda, A. 1991, Astr. Ap. , 244, 280.Google Scholar
Carney, B. W., Latham, D. W., & Laird, J. B. 1990, A.J. , 99, 572.Google Scholar
Gunn, J., Knapp, J., and Tremaine, S. 1979, A.J. , 84, 1181.Google Scholar
Majewski, S. R. 1990, , .Google Scholar
Majewski, S. R. 1992, Ap. J. Suppl. , in press.Google Scholar
Morrison, H. L., Flynn, C., & Freeman, K. C. 1990, A.J. , 100, 1191.Google Scholar
Norris, J. 1986, Ap. J. Suppl. , 61, 667.Google Scholar
Norris, J. & Ryan, S. G. 1989a, Ap. J. , 336, L17.Google Scholar
Norris, J. & Ryan, S. G. 1989b, Ap. J. , 340, 739.CrossRefGoogle Scholar
Pier, J. 1984, Ap. J. , 281, 260.CrossRefGoogle Scholar
Quinn, P. J. & Goodman, J. 1986, Ap. J. , 309, 472.Google Scholar
Ratnatunga, K. U. & Freeman, K. C. 1985, Ap. J. , 291, 260.Google Scholar
Rees, R. & Cudworth, K. M. 1991, A.J. , 102, 152.Google Scholar
Reid, N. 1990, M.N.R.A.S. , 247, 70.Google Scholar
Rodgers, A. W. & Paltoglou, G. 1984, Ap. J. , 283, L5.Google Scholar
Rodgers, A. W., Harding, P. & Sadler, E. 1981, Ap. J. , 244, 912.CrossRefGoogle Scholar
Searle, L. & Zinn, R. 1978, Ap. J. , 225, 357.Google Scholar