| "Dark matter" in accretion disks (2008) | |||||||||||
Abstract | |||||||||||
| Using Spitzer Space Telescope photometric observations of the eclipsing, interacting binary WZ Sge, we have discovered that the accretion disk is far more complex than previously believed. Our 4.5 and 8 µm time series observations reveal that the well-known gaseous accretion disk is surrounded by an asymmetric disk of dusty material with a radius approximately 15 times larger than the gaseous disk. This dust ring contains only a small amount of mass and is completely invisible at optical and near-IR wavelengths, hence consisting of "dark matter." We have produced a model dust ring using 1 µm spherical particles with a density of 3 g cm^(-3) and with a temperature profile ranging from 700 to 1500 K. Our discovery about the accretion disk structure and the presence of a larger, outer dust ring have great relevance for accretion disks in general, including those in other interacting binary systems, pre-main-sequence stars, and active galaxies. | |||||||||||
Publication details | |||||||||||
| |||||||||||