arXiv 1409.30152014-09-10astro-ph.SR

从LMC中发光蓝色变量R71返回的尘埃成分和质量损失

Dust composition and mass-loss return from the luminous blue variable R71 in the LMC

S. Guha Niyogi, M. Min, M. Meixner, L. B. F. M. Waters, J. Seale, A. G. G. M. Tielens

备注：: 10 pages, 6 figures, 2 tables
发表信息：: A&A 569, A80 (2014)
DOI：: 10.1051/0004-6361/201423746

摘要：

本文分析了大麦哲伦星云LBV R71的中远红外光谱和光谱能量分布，旨在了解大麦哲伦星云中大质量LBV对星际介质总尘埃质量收支的贡献，并与小质量渐近巨星支（AGB）星的贡献进行比较。作为一个案例研究，我们分析了R71的SED。我们收集了各种望远镜在宽波长范围（0.36 - 250 μ m，$μ$ m）的所有可用的测光和分光观测通量。我们确定了尘埃成分的光谱数据，并推导出喷出的尘埃质量，尘埃质量损失率，和其他尘埃壳的属性通过建模的SED的R71。通过对斯皮策光谱数据的分析，我们注意到R71尘埃壳层的9个光谱特征。其中，我们确定了三个新的结晶硅酸盐功能。我们使用三维辐射传输程序MCMax计算了我们的模型光谱。我们的模型计算表明，尘埃是由无定形硅酸盐为主，与一些结晶硅酸盐，金属铁，和非常微量的多环芳烃（PAH）分子。硅酸盐和多环芳烃的存在表明尘埃具有混合化学性质。我们推导出了0.01 M $_\odot$的尘埃质量，由此得出总喷射质量为$\approx$ 5 M $_\odot$。这意味着时间平均的尘埃质量损失率为2.5 $\times$ 10 $^{-6}$ M $_\odot$ \，年$^{-1}$与爆炸约4000年前。我们假设，其他五个已证实的尘埃LBV在LMC松散的质量在一个类似的速度，并估计总的贡献，LMC的质量预算为$\approx$ 10 $^{-5}$ M $_\odot$ \，年$^{-1}$，这是可比的贡献，所有的AGB星在LMC。根据我们对R71的分析，我们推测LBVs作为一类可能是LMC ISM中的一个重要尘源。

英文摘要：

We present an analysis of mid-and far-infrared (IR) spectrum and spectral energy distribution (SED) of the LBV R71 in the LMC.This work aims to understand the overall contribution of high-mass LBVs to the total dust-mass budget of the interstellar medium (ISM) of the LMC and compare this with the contribution from low-mass asymptotic giant branch (AGB) stars. As a case study, we analyze the SED of R71. We compiled all the available photometric and spectroscopic observational fluxes from various telescopes for a wide wavelength range (0.36 -- 250\,$μ$m). We determined the dust composition from the spectroscopic data, and derived the ejected dust mass, dust mass-loss rate, and other dust shell properties by modeling the SED of R71. We noted nine spectral features in the dust shell of R71 by analyzing Spitzer spectroscopic data. Among these, we identified three new crystalline silicate features. We computed our model spectrum by using 3D radiative transfer code MCMax. Our model calculation shows that dust is dominated by amorphous silicates, with some crystalline silicates, metallic iron, and a very tiny amount of polycyclic aromatic hydrocarbon (PAH) molecules. The presence of both silicates and PAHs indicates that the dust has a mixed chemistry. We derived a dust mass of 0.01 M$_\odot$, from which we arrive at a total ejected mass of $\approx$ 5 M$_\odot$. This implies a time-averaged dust mass-loss rate of 2.5$\times$10$^{-6}$ M$_\odot$\,yr$^{-1}$ with an explosion about 4000 years ago. We assume that the other five confirmed dusty LBVs in the LMC loose mass at a similar rate, and estimate the total contribution to the mass budget of the LMC to be $\approx$ 10$^{-5}$ M$_\odot$\,yr$^{-1}$, which is comparable to the contribution by all the AGB stars in the LMC. Based on our analysis on R71, we speculate that LBVs as a class may be an important dust source in the ISM of the LMC.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文