We present contemporaneous XMM-Newton X-ray and ground-based optical/near-IR spectroscopic observations of the nearby ( D \approx 42 pc ) , low-mass ( mid-M ) binary system TWA 30A and 30B .
The components of this wide ( separation \sim 3400 AU ) binary are notable for their nearly edge-on disk viewing geometries , high levels of variability , and evidence for collimated stellar outflows .
We obtained XMM-Newton X-ray observations of TWA 30A and 30B in 2011 June and July , accompanied ( respectively ) by IRTF SpeX ( near-IR ) and VLT XSHOOTER ( visible/near-IR ) spectroscopy obtained within \sim 20 hours of the X-ray observations .
TWA 30A was detected in both XMM-Newton observations at relatively faint intrinsic X-ray luminosities ( L _ { X } \sim 8 \times 10 ^ { 27 } erg s ^ { -1 } ) compared to stars of similar mass and age .
The intrinsic ( 0.15-2.0 keV ) X-ray luminosities measured in 2011 had decreased by a factor 20-100 relative to a 1990 ( ROSAT ) X-ray detection .
TWA 30B was not detected , and we infer an upper limit of ( L _ { X } \lesssim 3.0 \times 10 ^ { 27 } erg s ^ { -1 } ) .
We measured a large change in visual extinction toward TWA 30A ( from A _ { V } \approx 14.9 to A _ { V } \approx 4.7 ) between the two 2011 observing epochs , and we find evidence for a corresponding significant decrease in X-ray absorbing column ( N _ { H } ) .
The apparent correlated change in A _ { V } and N _ { H } is suggestive of variable obscuration of the stellar photosphere by disk material composed of both gas and dust .
However , in both observations , the inferred N _ { H } to A _ { V } ratio is lower than that typical of the ISM , suggesting that the disk is either depleted of gas or is deficient in metals in the gas phase .