New and Updated Rossiter-McLaughlin Measurements for Three Hot Jupiter-Hosting M Dwarfs

Abstract: Evidence suggests that Kozai-Lidov high-eccentricity migration (HEM) is the dominant migration channel for short-period Giant Exoplanets around M dwarf Stars (GEMS). However, it is unlikely that all short-period GEMS form via HEM, given that most systems lack known massive companions capable of driving HEM. Characterizing the stellar obliquities of GEMS via the Rossiter-McLaughlin (RM) effect can help shed light on the dynamical histories of GEMS. We present RM effect detections for the GEMS TOI-5205 b, TIC 46432937 b, and TOI-3714 b using the Gemini-North/MAROON-X spectrograph, bringing the total number of GEMS with RM detections to five. Our systems are well-aligned, with sky-projected obliquities of $λ= 0 \pm 6^{\circ$, $3_{-3}^{{+4}$^\circ,}}and,</sup></sup> and 15_{-8}^{+12}<sup>∘<sup>\circ, respectively, and we measure a deprojected obliquity of $ψ= 24_{-8}<sup>{+7}$ $<sup>\circ$ for TOI-3714. We analyze archival radial velocities, astrometry, and speckle imaging data to search for additional companions around all five known GEMS with RM detections. We find tentative evidence for a new massive companion around one of these GEMS, TOI-5293 A, in Gaia DR2+DR3 data, though further follow-up is needed for confirmation. We rule out massive companions between $\sim 1-10\textrm{ AU}$ in the remaining systems, but cannot rule out all companions capable of driving HEM. Our findings present further evidence that short-period GEMS are preferentially aligned. While current results remain consistent with both primordial alignment and HEM plus tidal damping, we offer future directions for studies to further constrain the dominant migration channel for GEMS.