SPIRou Input Catalogue: Global properties of 440 M dwarfs observed with ESPaDOnS at CFHT

TL;DR

This paper presents a detailed analysis of 440 M dwarfs observed with ESPaDOnS, deriving their fundamental properties to optimize target selection for the SPIRou planet search program.

Contribution

It introduces methods for determining effective temperature, metallicity, and rotation velocity for M dwarfs, and provides a comprehensive catalog to aid in selecting optimal stars for exoplanet surveys.

Findings

Calibration of rotation velocity versus line width for M dwarfs.

Comparison of derived stellar parameters with literature values.

Estimation of radial velocity uncertainties for target selection.

Abstract

Present and future high-precision radial-velocity spectrometers dedicated to the discovery of low-mass planets orbiting low-mass dwarfs need to focus on the best selected stars to make an efficient use of telescope time. In the framework of the preparation of the SPIRou Input Catalog, the CoolSnap program aims at screening M dwarfs in the solar neighborhood against binarity, rapid rotation, activity, ... To optimize the selection, the present paper describes the methods used to compute effective temperature, metallicity, projected rotation velocity of a large sample of 440 M dwarfs observed in the visible with the high-resolution spectro-polarimeter ESPaDOnS at CFHT. It also summarizes known and newly-discovered spectroscopic binaries, and stars known to belong to visual multiple systems. A calibration of the projected rotation velocity versus measured line widths for M dwarfs observed by the ESPaDOnS spectro-polarimeter is derived, and the resulting values are compared to equatorial rotation velocities deduced from rotation periods and radii. A comparison of the derived effective temperatures and metallicities with literature values is also conducted. Finally, the radial velocity uncertainty of each star in the sample is estimated, to narrow down the selection of stars to be included into the SPIRou Input Catalogue (SPIC).