Rxte Long-term Monitoring Of Hard X-ray Bright Symbiotics, Ch Cyg And T Cr

We (Kennea et al. 2009, ApJ 701, 1992) have recently established a small subset of symbiotic stars as bright hard X-ray sources, detected in the Swift/BAT and INTEGRAL surveys. There is still much that we do not know about the hard X-rays from these objects, including their long-term flux history. Unfortunately, the Swift/BAT and INTEGRAL surveys are of limited use in this regard, because these symbiotic stars cannot be reliably detected in short integrations using these instruments. We have therefore initiated an RXTE/PCA monitoring campaign on two hard X-ray symbiotics, CH Cyg and T CrB, in 2007 July. Here we report on the results using over 2 years of data, and consider their implications on our understanding of accretion disks in these symbiotic stars.