论文标题
光解离区域的拉曼映射
Raman mapping of photodissociation regions
论文作者
论文摘要
氢管道的宽拉曼散布翅膀可用于绘制由恒星形成区域中高质量恒星照明的中性气体。拉曼散射将遥远的星光从莱曼beta线的翅膀（1022 Angstrom到1029 Angstrom）转变为H Alpha线（6400 Angstrom至6700 Angstrom）的红色视觉光。对猎户座棒和猎户座星云中其他区域的空间分辨光谱的分析表明，该过程发生在电离阵线和解离沿之间的中性光脱离区域中。内部拉曼翅膀是光学厚的，允许确定中性氢密度，这意味着N（H0）〜= 100,000 CM对于猎户座棒。中性氧的远硫酸酯共振线在穿过电离前方时吸收其吸收到恒星连续体上，从而在6633 Angstrom和6664 Angstrom处产生特征吸收线，并具有2 angstrom的宽度。这是拉曼散射的独特签名，它可以轻松地将其与可能产生宽Hα机翼的其他过程区分开，例如电子散射或高速流出。
Broad Raman-scattered wings of hydrogen lines can be used to map neutral gas illuminated by high-mass stars in star forming regions. Raman scattering transforms far-ultraviolet starlight from the wings of the Lyman beta line (1022 Angstrom to 1029 Angstrom) to red visual light in the wings of the H alpha line (6400 Angstrom to 6700 Angstrom). Analysis of spatially resolved spectra of the Orion Bar and other regions in the Orion Nebula shows that this process occurs in the neutral photo-dissociation region between the ionization front and dissociation front. The inner Raman wings are optically thick and allow the neutral hydrogen density to be determined, implying n(H0) ~= 100,000 per cubic cm for the Orion Bar. Far-ultraviolet resonance lines of neutral oxygen imprint their absorption onto the stellar continuum as it passes through the ionization front, producing characteristic absorption lines at 6633 Angstrom and 6664 Angstrom with widths of order 2 Angstrom. This is a unique signature of Raman scattering, which allows it to be easily distinguished from other processes that might produce broad H alpha wings, such as electron scattering or high-velocity outflows.
