SPITZER OBSERVATIONS OF THE OLDEST WHITE DWARFS IN THE SOLAR NEIGHBORHOOD
SPITZER OBSERVATIONS OF THE OLDEST WHITE DWARFS IN THE SOLAR NEIGHBORHOOD
复制标题
斯皮策望远镜对太阳系附近最古老的白矮星的观测
DOI：
10.1088/0004-637x/696/2/2094
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
T. von Hippel
中科院分区：
文献类型：
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作者：
M. Kilic;P. Kowalski;W. Reach;T. von Hippel
研究了一颗冷白矮星的5-15 μm光谱和51颗Teff < 6000 K的冷白矮星的3.6-8 μm光度。我们的大部分目标都有精确的BVRIJHK光度测量和三角视差测量，这使我们能够使用他们的光学，近红外和中红外光度测量技术和最先进的模型大气进行详细的模型大气分析。我们证明，我们的模型网格能很好地再现冷白矮星的光学和红外光谱能量分布。除了IRAC 8 μm波段具有最低的信噪比外，我们的最佳拟合模型与所有滤光片的观测结果在5%以内一致。除了超冷白矮星，我们的样本中没有一颗恒星显示出明显的中红外通量不足或过剩。在我们的≈2-9 Gyr老目标周围没有检测到中红外过剩通量，这限制了具有温暖碎片盘的冷白矮星的比例为0.8+1.5−0.8%。
We present Spitzer 5–15 μm spectroscopy of one cool white dwarf and 3.6–8 μm photometry of 51 cool white dwarfs with Teff < 6000 K. The majority of our targets have accurate BVRIJHK photometry and trigonometric parallax measurements available, which enables us to perform a detailed model atmosphere analysis using their optical, near- and mid-infrared photometry with state-of-the-art model atmospheres. We demonstrate that the optical and infrared spectral energy distributions of cool white dwarfs are well reproduced by our grid of models. Our best-fit models are consistent with the observations within 5% in all filters except the IRAC 8 μm band, which has the lowest signal-to-noise ratio photometry. Excluding the ultracool white dwarfs, none of the stars in our sample show significant mid-infrared flux deficits or excesses. The nondetection of mid-infrared excess flux around our ≈2–9 Gyr old targets constrain the fraction of cool white dwarfs with warm debris disks to 0.8+1.5−0.8 %.