Doppler Flips in Protoplanetary & Debris Disks: A Possible Indicator of Hidden Planets

Live Poster Session: Zoom Link
Thursday, July 30th 1:15-2:30pm EDT

Hannah Lewis
Hannah Lewis

Hannah Lewis is a rising sophomore (’23) from Philadelphia, PA who graduated from Souderton Area High School. At Wesleyan, Hannah is a part of the WesMaSS program and Wesleyan Women in Science (WesWIS). She would like to major in Astronomy, with an interest in further pursuing research after graduation.

Abstract: Protoplanetary disks are flattened structures of gas and optically thick dust around young stars (<10 Myr old). Debris disks are older, more evolved disks with optically thin dust levels. Recent work has shown that deviations from Keplerian rotation in the spectral line analysis of protoplanetary disks can point to the presence of exoplanets that are otherwise difficult to detect. The deviations from Keplerian rotation studied here include velocity kinks/wiggles and Doppler Flips. Doppler Flips are observable in the residuals of intensity-weighted velocity (first moment map) model fitting. The purpose of this study was to apply these methods, previously used on protoplanetary disk data, to debris disk data. We used spectral line emission data from the Atacama Large Millimeter/submillimeter Array (ALMA). We first verified the presence of velocity kinks/wiggles and Doppler Flips in the protoplanetary disk 12CO(J=2-1) emission data of HD163296, confirming the results of previous studies. The analysis of CI(3P1-3P0) and CO(J=3-2) emission data for the gas-rich debris disk 49 Ceti did not show any velocity kinks/wiggles, however disk models do indicate moderate evidence of a warp, a possibility considered in previous studies. Our analysis rules out planets orbiting 49 Ceti with semimajor axes between 60 and 260 au and provides proof of concept for similar studies of a wider variety of debris disks in the future.

Lewis_Poster2020-Hannah-Lewis

Live Poster Session: Zoom Link
Thursday, July 30th 1:15-2:30pm EDT

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