http://arxiv.org/abs/2201.10465
We present the results of 15 years of VISNIR spectral monitoring studying the famously variable RW Aur A classical T Tauri star (CTTS) system. We find direct evidence for a highly excited classical T Tauri star surrounded by an IR bright, asymmetric, and time variable accretion disk. Comparison of the spectral and temporal trends found in long term SpeX monitoring determines 5 different components: (1) a stable continuum from 0.7 – 1.3 um, with color temperature 4000K, produced by the CTTS photospheric surface; (2) variable hydrogen emission lines emitted from hot excited hydrogen in the CTTS protostellar atmosphere-accretion envelope; (3) hot CO gas in the CTTS protostellar atmosphere/accretion envelope; (4) highly variable 1.8-5.0 um thermal continuum emission with color temperature ranging from 1130 to 1650K, due to a surrounding accretion disk that is spatially variable and has an inner wall at r = 0.04 AU and T=1650K, and outer edges at 1130K; and (5) transient signatures of abundant Fe II + associated SI, SiI, and SrI in the systems jet structures created by the catastrophic disruption of a planetesimal core. The Fe II signatures first appeared in 2015 as highly bifurcated jet lines, but these collapsed and disappeared into a small single peak protostellar atmosphere feature by late 2020. By contrast, nearby, coeval binary companion RW Aur B evinces only (1) a stable WTTS photospheric continuum from 0.7 – 1.3 um + (3) cold CO gas in absorption + (4) stable 1.8-5.0 um thermal continuum emission with color temperature 1650K. The temporal evolution of the RW Aur A spectral signatures we find is consistent with a dynamically excited CTTS system forming differentiated Vesta-sized planetesimals in an asymmetric accretion disk and migrating them inward to be destructively accreted.
C. Lisse, M. Sitko, S. Wolk, et. al.
Wed, 26 Jan 22
29/53
Comments: 38 Pages, 16 Figures, 2 Tables
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