GCIRS之谜3 --用光学长基线干涉测量约束Milky Way中央秒差距的中红外参考星的性质
The enigma of GCIRS 3 - Constraining the properties of the mid-infrared reference star of the central parsec of the Milky Way with optical long baseline interferometry
摘要：
GCIRS 3是银河系中央pc中最突出的MIR源。近红外光谱未能解决其性质之谜。中央星团极端个体的性质有助于我们了解靠近超大质量黑洞的恒星和尘埃的形成。我们开始了一个干涉实验，以了解IRS 3和研究它的光谱和干涉参考星在10 μ m的属性。VISIR成像将致密源与周围的漫射辐射分开。VLTI/VLT仪器被用来测量该紧凑的10 μ m源的10质量分辨率下的能级，该能级仍然不能被单个VLT分辨。增加了光度测定数据，以实现简单的SED-和完整的辐射转移-模型的数据。光度和大小估计显示IRS 3可能是一颗被复杂尘埃分布所覆盖的冷碳星。尘埃温度的推导。多个数据集的一致解释证实了在几个空间尺度上的粉尘排放。中频数据解决了尘埃形成的最内部区域。尽管观察到深硅酸盐吸收对IRS 3，我们赞成富碳化学的拱星尘埃壳。硅酸盐的吸收很可能发生在外部的弥漫尘埃，这是大多数被忽略的ESTA测量。这表明当地尘埃的物理和化学条件不同，随着与IRS 3的距离而变化。我们已经证明，在红外波长的光学长基线干涉测量是一个不可或缺的工具，调查在银河系中心的来源。我们的研究结果建议进一步研究星际尘埃的组成和在这个突出的区域的10微米硅酸盐特征的形状。
英文摘要：
GCIRS3 is the most prominent MIR source in the central pc of the Galaxy. NIR spectroscopy failed to solve the enigma of its nature. The properties of extreme individual objects of the central stellar cluster contribute to our knowledge of star and dust formation close to a supermassive black hole. We initiated an interferometric experiment to understand IRS3 and investigate its properties as spectroscopic and interferometric reference star at 10um. VISIR imaging separates a compact source from diffuse, surrounding emission. The VLTI/MIDI instrument was used to measure visibilities at 10mas resolution of that compact 10um source, still unresolved by a single VLT. Photometry data were added to enable simple SED- and full radiative transfer-models of the data. The luminosity and size estimates show that IRS3 is probably a cool carbon star enshrouded by a complex dust distribution. Dust temperatures were derived. The coinciding interpretation of multiple datasets confirm dust emission at several spatial scales. The IF data resolve the innermost area of dust formation. Despite observed deep silicate absorption towards IRS3 we favor a carbon rich chemistry of the circumstellar dust shell. The silicate absorption most probably takes place in the outer diffuse dust, which is mostly ignored by MIDI measurements. This indicates physically and chemically distinct conditions of the local dust, changing with the distance to IRS3. We have demonstrated that optical long baseline interferometry at infrared wavelengths is an indispensable tool to investigate sources at the Galactic Center. Our findings suggest further studies of the composition of interstellar dust and the shape of the 10um silicate feature at this outstanding region.
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。
