Deriving the metallicity distribution function of Galactic systems

被引:58
作者
Fenner, Y [1 ]
Gibson, BK [1 ]
机构
[1] Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia
来源
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA | 2003年 / 20卷 / 02期
关键词
galaxy : solar neighbourhood; evolution; stars : abundances;
D O I
10.1071/AS02047
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The chemical evolution of the Milky Way is investigated using a dual-phase metal-enriched infall model in which primordial gas fuels the earliest epoch of star formation, followed by the ongoing formation of stars from newly accreted gas. The latest metallicity distribution of local K-dwarfs is reproduced by this model, which allows the Galactic thin disk to form from slightly metal-enriched gas with alpha-element enhancement. Our model predicts ages for the stellar halo and thin disk of 12.5 and 7.4 Gyr respectively, in agreement with empirically determined values. The model presented in this paper is compared with a similar dual-phase infall model from Chiappini et al. ( 2001). We discuss a degeneracy that enables both models to recover the K-dwarf metallicity distribution while yielding different star formation histories. The metallicity distribution function (MDF) of K-dwarfs is proposed to be more directly comparable to chemical evolution model results than the G-dwarf distribution because lower mass K-dwarfs are less susceptible to stellar evolutionary effects. The K-dwarf MDF should consequently be a better probe of star formation history and provide a stronger constraint to chemical evolution models than the widely used G-dwarf MDF. The corrections that should be applied to a G-dwarf MDF are quantified for the case of the outer halo of NGC 5128.
引用
收藏
页码:189 / 195
页数:7
相关论文
共 42 条
[11]  
GIBSON BK, 2001, AJ, V547, P3280
[12]   A DETERMINATION OF THE THICK DISK CHEMICAL ABUNDANCE DISTRIBUTION IMPLICATIONS FOR GALAXY EVOLUTION [J].
GILMORE, G ;
WYSE, RFG ;
JONES, JB .
ASTRONOMICAL JOURNAL, 1995, 109 (03) :1095-1111
[13]  
Goswami A, 2000, ASTRON ASTROPHYS, V359, P191
[14]   The white dwarf cooling sequence of the globular cluster Messier 4 [J].
Hansen, BMS ;
Brewer, J ;
Fahlman, GG ;
Gibson, BK ;
Ibata, R ;
Limongi, M ;
Rich, RM ;
Richer, HB ;
Shara, MM ;
Stetson, PB .
ASTROPHYSICAL JOURNAL, 2002, 574 (02) :L155-L158
[15]   Halo stars in NGC 5128. II. An outer halo field and a new metallicity distribution [J].
Harris, GLH ;
Harris, WE .
ASTRONOMICAL JOURNAL, 2000, 120 (05) :2423-2436
[16]   The halo stars in NGC 5128. III. An inner halo field and the metallicity distribution [J].
Harris, WE ;
Harris, GLH .
ASTRONOMICAL JOURNAL, 2002, 123 (06) :3108-3123
[17]   A revision of the solar neighbourhood metallicity distribution [J].
Haywood, M .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2001, 325 (04) :1365-1382
[18]  
HOU JL, 1998, PAC RIM C STELL ASTR, P143
[19]   HIPPARCOS age-metallicity relation of the solar neighbourhood disc stars [J].
Ibukiyama, A ;
Arimoto, N .
ASTRONOMY & ASTROPHYSICS, 2002, 394 (03) :927-941
[20]   K dwarfs and the chemical evolution of the solar cylinder [J].
Kotoneva, E ;
Flynn, C ;
Chiappini, C ;
Matteucci, F .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2002, 336 (03) :879-891