Echo-Mapping a Quiescent Black Hole

Black holes of all sizes, from stellar mass to supermassive, undergo quiescentperiods. The quiescent behavior likely differs from luminous phases, but thereare large uncertainties in the geometry and physical conditions of the accretinggas. At a basic level, we do not even know if observed emission is dominated byinflowing or outflowing gas. We propose a detailed multiwavelength study of thebrightest quiescent stellar mass black hole, V404 Cyg. We will build upon ourprevious successful observations and will i) use an echomapping experiment toexplore the structure and conditions of the outer disk and test the origin ofthe optical continuum emission; ii) obtain a high quality Xray continuumspectrum; iii) search for fluorescent iron line emission. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]