Debris Disks around White Dwarfs: The DAZ Connection
Debris Disks around White Dwarfs: The DAZ Connection
复制标题
白矮星周围的碎片盘：DAZ 连接
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
D. Winget
中科院分区：
文献类型：
--
作者：
M. Kilic;M. Kilic;T. Hippel;S. Leggett;D. Winget
我们目前的近红外光谱观测20个以前已知的DAZ白色矮星在美国宇航局红外望远镜设施。其中两颗白色矮星（G29-38和GD 362）由于星周碎片盘的存在而显示出明显的K波段过度。在这里，我们报告了从另一个DAZ白色矮星WD 0408-041（GD 56）中发现的过量K波段辐射。使用光谱观测，我们表明，过量的辐射不能解释的恒星或亚恒星的同伴，很可能是由一个温暖的碎片盘。我们的观测加强了碎片盘现象和冷DAZ白色矮星中观测到的金属丰度之间的联系。然而，我们没有发现任何过量的红外发射，从最富金属DAZ与Teff = 16，000 - 20，000 K。这表明，在较温暖的DAZ白色矮星中的金属丰度可能需要另一种解释。
We present near-infrared spectroscopic observations of 20 previously known DAZ white dwarfs obtained at the NASA Infrared Telescope Facility. Two of these white dwarfs (G29-38 and GD 362) are known to display significant K-band excesses due to circumstellar debris disks. Here we report the discovery of excess K-band radiation from another DAZ white dwarf, WD 0408-041 (GD 56). Using spectroscopic observations, we show that the excess radiation cannot be explained by a stellar or substellar companion, and is likely to be caused by a warm debris disk. Our observations strengthen the connection between the debris disk phenomena and the observed metal abundances in cool DAZ white dwarfs. However, we do not find any excess infrared emission from the most metal rich DAZs with Teff = 16,000-20,000 K. This suggests that the metal abundances in warmer DAZ white dwarfs may require another explanation.