Beat cepheids as probes of stellar and galactic metallicity. II. Opacities with the AGS mixture

被引:19
作者
Buchler, J. Robert [1 ]
机构
[1] Univ Florida, Dept Phys, Gainesville, FL 32611 USA
关键词
Cepheids; galaxies : abundances; stars : oscillations; stars : rotation;
D O I
10.1086/588547
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
It is well known that the mere location of a beat Cepheid model in a period ratio versus period diagram (Petersen diagram) puts constraints on its metallicity Z. But these bounds are sensitive to the mixture of elements that are lumped into the parameter Z. In this short paper we update the previous results that were based on the Grevesse-Noels solar mixture to the recent, revised Asplund, Grevesse,& Sauval (AGS) solar mixture. We also examine the effect of the envelope depth on the accuracy of the computed pulsation periods. We find that for low-period Cepheids with high Z the customary approximation of envelope pulsation breaks down. It is necessary to compute stellar models that extend to the center and to include burning and composition inhomogeneities in the modeling. Fortunately, however, most beat Cepheids that have been observed so far seem to avoid that regime.
引用
收藏
页码:1412 / 1416
页数:5
相关论文
共 10 条
  • [1] LOW-TEMPERATURE ROSSELAND OPACITIES
    ALEXANDER, DR
    FERGUSON, JW
    [J]. ASTROPHYSICAL JOURNAL, 1994, 437 (02) : 879 - 891
  • [2] Asplund M, 2005, ASTR SOC P, V336, P25
  • [3] Detection of beat Cepheids in M33 and their use as a probe of the M33 metallicity distribution
    Beaulieu, J. -P.
    Buchler, J. Robert
    Marquette, J. -B.
    Hartman, J. D.
    Schwarzenberg-Czerny, A.
    [J]. ASTROPHYSICAL JOURNAL, 2006, 653 (02) : L101 - L104
  • [4] Beat cepheids as probes of stellar and galactic metallicity
    Buchler, J. Robert
    Szabo, Róbert
    [J]. ASTROPHYSICAL JOURNAL, 2007, 660 (01) : 723 - 731
  • [5] ON THE MODAL SELECTION OF RADIAL STELLAR PULSATORS
    BUCHLER, JR
    KOVACS, G
    [J]. ASTROPHYSICAL JOURNAL, 1986, 308 (02) : 661 - 668
  • [6] GREVESSE N, 1993, ORIGIN EVOLUTION ELE, P14
  • [7] Updated OPAL opacities
    Iglesias, CA
    Rogers, FJ
    [J]. ASTROPHYSICAL JOURNAL, 1996, 464 (02) : 943 - 953
  • [8] Nonlinear beat Cepheid models
    Kolláth, Z
    Beaulieu, JP
    Buchler, JR
    Yecko, P
    [J]. ASTROPHYSICAL JOURNAL, 1998, 502 (01) : L55 - L58
  • [9] Nonlinear beat Cepheid and RR Lyrae models
    Kolláth, Z
    Buchler, JR
    Szabó, R
    Csubry, Z
    [J]. ASTRONOMY & ASTROPHYSICS, 2002, 385 (03) : 932 - 939
  • [10] CALCULATION OF PERIODIC PULSATIONS OF STELLAR MODELS
    STELLINGWERF, RF
    [J]. ASTROPHYSICAL JOURNAL, 1974, 192 (01) : 139 - 144