4-8 October 2015
Hans Harnack Haus
Europe/Berlin timezone
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Contribution Contributed Talk

Hans Harnack Haus -

Resolved High-J 13CO Emission as a Sensitive Probe of Disk Structure and Chemistry


  • Ms. Kamber SCHWARZ

Primary authors



We present our new ALMA observations of $^{13}$CO and C$^{18}$O 6-5 in TW Hya. These data include the first direct detection of the CO snow line in this system and exciting evidence of non-Keplarian structure in the inner 20 AU. Snow lines represent volatile sublimation fronts in protoplanetary disks, which are believed to aid in the growth of planetesimals. In this regard the $^{13}$CO 6-5 image shows a precipitous drop at 25 AU. Based on detailed models, and the previous detection using N$_2$H$^+$ (Qi et al 2013), this drop is constant with the evaporation front. We will also show that these data provide glimpses of structure in the radial abundance of CO, which has been shown to be depleted in this source. Additionally, these observations clearly show strong high velocity emission in the inner disk. Our modeling of these spectra indicate that a simple Keplerian velocity field is incapable of reproducing the observed line profiles, consistent with other recent high resolution observations of protoplanetary disks (e.g. Rosenfeld et al. 2013, Casassus et al. 2015). Using Markov Chain Monte Carlo techniques we explore a range of modified disk models, including a disk with a warped inclination and deviations from Keplerian rotation induced by an embedded planet. In all, this work provides the first complete picture of the CO abundance in an evolved T Tauri disk and shows the utility of high J CO emission as a tracer of structure likely induced by hidden young planets.