论文标题
来自老板和虹膜的弥漫性银河光的光谱
An Optical Spectrum of the Diffuse Galactic Light from BOSS and IRIS
论文作者
论文摘要
我们介绍了3700至10,000 a之间的弥漫性银河光(DGL),该光谱是通过将光学天空强度与远红外灰尘发射相关联获得的。我们使用了来自Boss/SDSS-III的近25万间空白光谱,以及来自IRAS卫星的IRIS重新处理的地图。与SDSS-II相比,较大的样本量导致两个信号增加到噪声。我们将这些数据集与光学/远红外相关的模型相结合,该模型解释了灰尘自我吸收。 DGL的光谱特征与恒星光谱中的特征非常吻合。有证据表明,北部和南部银半球的老板覆盖的地区之间的DGL连续体有所不同。我们解释了由于恒星种群差异而导致的红色波长的差异,这两个地区主要是旧星星,但南部的年轻恒星的较高部分。南部DGL频谱的预测也有很大的过量,而北部没有明显的辐射转移模型。我们将其解释为以〜6500 a为中心,以延长红发射(ERE)形式的发光证据。观察到的4000 a断裂的强度表明,在4000 a时最多约7%的尘埃光可能是由于蓝色发光。我们的DGL光谱对尘埃散射和发光提供了限制,而与灭绝的测量无关。
We present a spectrum of the diffuse Galactic light (DGL) between 3700 and 10,000 A, obtained by correlating optical sky intensity with far-infrared dust emission. We use nearly 250,000 blank-sky spectra from BOSS/SDSS-III together with IRIS-reprocessed maps from the IRAS satellite. The larger sample size compared to SDSS-II results in a factor-of-two increase in signal to noise. We combine these data sets with a model for the optical/far-infrared correlation that accounts for self-absorption by dust. The spectral features of the DGL agree remarkably well with features present in stellar spectra. There is evidence for a difference in the DGL continuum between the regions covered by BOSS in the northern and southern Galactic hemisphere. We interpret the difference at red wavelengths as the result of a difference in stellar populations, with mainly old stars in both regions but a higher fraction of young stars in the south. There is also a broad excess in the southern DGL spectrum over the prediction of a simple radiative transfer model, without a clear counterpart in the north. We interpret this excess, centered at ~6500 A, as evidence for luminescence in the form of extended red emission (ERE). The observed strength of the 4000 A break indicates that at most ~7% of the dust-correlated light at 4000 A can be due to blue luminescence. Our DGL spectrum provides constraints on dust scattering and luminescence independent of measurements of extinction.