RW Auriga: Iron rich corona and high absorbing column density

RW Aur A has undergone a visual dimming event in 2011 lasting about half a year and further dimming since 2014. We report on new Chandra X-ray data taken in 2017, when the optical flux was almost 2 mag below the long-term average. The observed X-ray spectrum is more absorbed by a column density of a few 10^23/cm^2 and shows significantly more hot plasma than in X-ray observations taken before the dimming. An emission feature at 6.62 keV indicates an Fe abundance an order of magnitude above Solar, in contrast with previous sub-Solar Fe abundance measurements. Given the high column density coupled with changes in the X-ray spectral shape, the absorber is probably located in the inner disk. We speculate that a break-up of planetesimals or a terrestrial planet could supply large grains. Some of these grains would be accreted and enrich the stellar corona with iron which could explain the inferred high abundance.