Relation between metallicities and spectral energy distributions of Herbig Ae/Be stars A potential link with planet formation
Relation between metallicities and spectral energy distributions of Herbig Ae/Be stars A potential link with planet formation
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Herbig Ae/Be 恒星的金属丰度和光谱能量分布之间的关系与行星形成的潜在联系
DOI：
10.1051/0004-6361/202245427
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发表时间：
2023
影响因子：
6.5
通讯作者：
Guzmán-Díaz J
中科院分区：
文献类型：
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作者：
Guzmán-Díaz J
背景：大多数致力于赫比格Ae/Be星（HAeBes）的研究都假设太阳的金属丰度。然而，恒星的金属丰度[M/H]是一个基本参数，可能会因来源而有很大差异，并可能对行星的形成产生重要影响。有人提出，在某些HAeBes表面观察到的难熔元素的不足可能与其盘中存在的空腔有关，并且可能是由木星行星捕获富含金属的内容物引起的。值和恒星和拱星的属性。方法。光谱的67 HAeBes，沿着与他们的知名的属性从我们以前的工作，已收集从ESO科学档案设施。它们的[M/H]值是根据与Kurucz合成模型的比较得出的。进行了统计分析，目的是测试[M/H]和Meeus I组源之间的潜在关系，光谱能量分布（SED）与巨行星可能雕刻的空腔的存在有关。我们批判性地分析了[M/H]、SED群和此类行星存在之间的最终联系。结果：我们的统计研究有力地证实了I族源的[M/H]（通常为-0.10）往往低于II族HAeBes（~ +0.14）。类似的分析涉及基于SED的过渡盘，仅在≥2.2 μm的波长处具有红外过量，没有揭示与[M/H]的这种关系。这一结果表明，并非所有能够在内部尘埃盘中产生孔洞的过程最终都会对恒星丰度产生影响。第一组和第二组源的空间分布是相似的，至少在银河系中心和银道面的距离范围内，观测到的[M/H]差异不是由环境影响驱动的。此外，第一组来源往往有较强的（亚）毫米连续发射推测与巨行星的存在。事实上，文献结果表明，可能与巨行星的存在有关的磁盘子结构在I组HAeBes中的频率是II组的十倍。最后，沿着与金属丰度得出的整个样品，表面重力和投影旋转速度是额外的成果，在这项工作中reported.Conclusions。我们提供的间接证据表明，巨行星更频繁地围绕组I/低[M/H]恒星比周围的其余的HAeBes。然而，对先前假设的直接检验需要多次探测到行星盘中形成的行星。到目前为止，这种探测仅限于金属耗尽（[M/H] = −0.35 ± −0.25）的I族HAeBe星星AB Aur周围的候选者，这与我们的发现一致。
Context.Most studies devoted to Herbig Ae/Be stars (HAeBes) assume solar metallicity. However, the stellar metallicity, [M/H], is a fundamental parameter that can strongly differ depending on the source and may have important implications for planet formation. It has been proposed that the deficit of refractory elements observed in the surfaces of some HAeBes may be linked to the presence of cavities in their disks and is likely caused by Jovian planets that trap the metal-rich content.Aims.This work aims to provide a robust test on the previous proposal by analyzing the largest sample of HAeBes characterized by homogeneously derived [M/H] values and stellar and circumstellar properties.Methods.The spectra of 67 HAeBes, along with their well-known properties drawn from our previous work, have been collected from the ESO Science Archive Facility. Their [M/H] values were derived based on the comparison with Kurucz synthetic models. Statistical analyses were carried out with the aim to test the potential relation between [M/H] and the Meeus group I sources, with spectral energy distributions (SEDs) associated with the presence of cavities potentially carved by giant planets. We critically analyzed the eventual link between [M/H], the SED groups, and the presence of such planets.Results.Our statistical study robustly confirms that group I sources tend to have a lower [M/H] (typically ~ −0.10) than that of group II HAeBes (~ +0.14). A similar analysis involving SED-based transitional disks, with infrared excess only at wavelengths of ≥2.2 µm, does not reveal such a relation with [M/H]. This result indicates that not all processes capable of creating holes in the inner dust disks end up having an effect on the stellar abundances. The spatial distributions of group I and II sources are similar, at least within the available range of distances to the galactic centre and the galactic plane, for which the observed [M/H] differences are not driven by environmental effects. In addition, group I sources tend to have stronger (sub-) mm continuum emission presumably related to the presence of giant planets. Indeed, literature results indicate that disk substructures probably associated with the presence of giant planets are up to ten times more frequent in group I HAeBes than in group II. Finally, along with the metallicities derived for the whole sample, surface gravities and projected rotational velocities are additional outcomes reported in this work.Conclusions.We provide indirect evidence to suggest that giant planets are more frequent around group I/low [M/H] stars than around the rest of the HAeBes. However, a direct test of the previous hypothesis requires multiple detections of forming planets in their disks. Such detections have so far been limited to the candidate around the metal depleted ([M/H] = −0.35 ± −0.25) group I HAeBe star AB Aur, which is consistent with our findings.