The Magellan-TESS Survey I: Survey Description and Mid-Survey Results
Creators: name: Teske, Johanna
name: Wang, Sharon Xuesong
name: Wolfgang, Angie
name: Gan, Tianjun
name: Plotnykov, Mykhaylo
name: Armstrong, David J.
name: Butler, R. Paul
name: Cale, Bryson
name: Crane, Jeffrey D.
name: Howard, Ward
name: Jensen, Eric L. N.
name: Law, Nicholas
name: Shectman, Stephen A.
name: Plavchan, Peter
name: Valencia, Diana
name: Vanderburg, Andrew
name: Ricker, George
name: Vanderspek, Roland
name: Latham, Dave W.
name: Seager, Sara
name: Winn, Joshua W.
name: Jenkins, Jon M.
name: Adibekyan, Vardan
name: Barrado, David
name: Barros, Susana C. C.
name: Benkhaldoun, Zouhair
name: Brown, David J. A.
name: Bryant, Edward M.
name: Burt, Jennifer
name: Caldwell, Douglas A.
name: Charbonneau, David
name: Cloutier, Ryan
name: Collins, Karen A.
name: Collins, Kevin I.
name: Colon, Nicole D.
name: Conti, Dennis M.
name: Demangeon, Olivier D. S.
name: Eastman, Jason D.
name: Elmufti, Mohammed
name: Feng, Fabo
name: Flowers, Erin
name: Guerrero, Natalia M.
name: Hojjatpanah, Saeed
name: Irwin, Jonathan M.
name: Isopi, Giovanni
name: Lillo-Box, Jorge
name: Mallia, Franco
name: Massey, Bob
name: Mori, Mayuko
name: Mullally, Susan E.
name: Narita, Norio
name: Nishiumi, Taku
name: Osborn, Ares
name: Paegert, Martin
name: de Leon, Jerome Pitogo
name: Quinn, Samuel N.
name: Reefe, Michael
name: Schwarz, Richard P.
name: Shporer, Avi
name: Soubkiou, Abderahmane
name: Sousa, Sérgio G.
name: Stockdale, Chris
name: Strøm, Paul A.
name: Tan, Thiam-Guan
name: Tenenbaum, Peter
name: Wheatley, Peter J.
name: Wittrock, Justin
name: Yahalomi, Daniel A.
name: Zohrabi, Farzaneh
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: $Kepler$ revealed that roughly one-third of Sun-like stars host planets orbiting within 100 days and between the size of Earth and Neptune. How do these planets form, what are they made of, and do they represent a continuous population or multiple populations? To help address these questions, we began the Magellan-TESS Survey (MTS), which uses Magellan II/PFS to obtain radial velocity (RV) masses of 30 TESS-detected exoplanets and develops an analysis framework that connects observed planet distributions to underlying populations. In the past, small planet RV measurements have been challenging to obtain due to host star faintness and low RV semi-amplitudes, and challenging to interpret due to the potential biases in target selection and observation planning decisions. The MTS attempts to minimize these biases by focusing on bright TESS targets and employing a quantitative selection function and observing strategy. In this paper, we (1) describe our motivation and survey strategy, (2) present our first catalog of planet density constraints for 27 TESS Objects of Interest (TOIs; 22 in our population analysis sample, 12 that are members of the same systems), and (3) employ a hierarchical Bayesian model to produce preliminary constraints on the mass-radius (M-R) relation. We find that the biases causing previous M-R relations to predict fairly high masses at $1~R_\oplus$ have been reduced. This work can inform more detailed studies of individual systems and offer a framework that can be applied to future RV surveys with the goal of population inferences.
description: Minor updates to some masses, and new exploration of broken power law M-R relation. 66 pages (now some figures moved to figure sets, will be in HTML published version). Accepted to ApJS on June 22, 2021