Abstract

We present the results of our determination of the fundamental atmospheric parameters for the magnetic chemically peculiar Ap stars HD 110066 (AX CVn) and HD 153882 (V451 Her). The determination of the atmospheric parameters (\(T_{\textrm{eff}}\), \(\textrm{log}{g}\), \(R/R_{\odot}\), and \(L/L_{\odot}\)) is based on a self-consistent analysis of high-resolution spectra (ESPaDOnS with \(R=65\,000\)) and the observed flux distribution in a wide spectral range. We have derived the radial magnetic field components \(B_{r}=4015\pm 180\) G for HD 110066 and \(B_{r}=3800\pm 200\) G for HD 153882 from the observed line splitting and magnetic differential broadening. We have analyzed the chemical composition and the vertical distribution (stratification) of Fe and Cr in atmospheric depth, because the lines of these elements make the greatest contribution to the absorption and stratification affects the distribution of the outgoing flux. We have constructed model atmospheres and determined the evolutionary status of these stars by taking into account the anomalous chemical composition and stratification. The positions of HD 110066 and HD 153882 on the Hertzsprung–Russell diagram confirm the observed decrease in the magnetic field strength with stellar age for stars with masses greater than 2.5 \(M_{\odot}\).

中文翻译：

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Ap Stars HD 110066和HD 153882的进化状态

摘要

我们介绍了确定磁性化学特殊Ap星HD 110066（AX CVn）和HD 153882（V451 Her）的基本大气参数的结果。大气参数（\（T _ {\ textrm {eff}} \），\（\ textrm {log} {g} \），\（R / R _ {\ odot} \）和\（L / L _ {\ odot} \））基于高分辨率光谱（ESPaDOnS具有\（R = 65 \，000 \））和在宽光谱范围内观察到的通量分布的自洽分析。我们为HD 110066和\（B_ {r} = 3800 \ pm 200 \）导出了径向磁场分量\（B_ {r} = 4015 \ pm 180 \） G从观察到的线分裂和磁差扩展看，HD 153882的G。我们已经分析了大气中Fe和Cr的化学成分和垂直分布（分层），因为这些元素的线对吸收和分层的贡献最大，并且分层影响流出通量的分布。我们已经构造了大气模型，并通过考虑异常的化学成分和分层来确定了这些恒星的演化状态。HD 110066和HD 153882在Hertzsprung-Russell图上的位置证实了质量大于2.5 \（M _ {\ odot} \）的恒星，随着星体年龄的观察到的磁场强度下降。