Searching for the metal-weak thick disc in the solar neighbourhood

نویسندگان

  • Bacham E. Reddy
  • David L. Lambert
چکیده

An abundance analysis is presented of 60 metal-poor stars drawn from catalogues of nearby stars provided by Ariyanto et al. (2005) and Schuster et al. (2006). In an attempt to isolate a sample of metal-weak thick disc stars, we applied the kinematic criteria Vrot ≥ 100 km s , |ULSR| ≤ 140 km s , and |WLSR| ≤ 100 km s . Fourteen stars satisfying these criteria and having [Fe/H] ≤ −1.0 are included in the sample of 60 stars. Eight of the 14 have [Fe/H] ≥ −1.3 and may be simply thick disc stars of slightly lower than average [Fe/H]. The other six have [Fe/H] from −1.3 to −2.3 and are either metal-weak thick disc stars or halo stars with kinematics mimicking those of the thick disc. The sample of 60 stars is completed by eight thick disc stars, 20 stars of a hybrid nature (halo or thick disc stars), and 18 stars with kinematics distinctive of the halo.

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تاریخ انتشار 2008