Effective Temperatures of Low-Mass Stars from High-Resolution H-band Spectroscopy

Abstract

High-resolution, near-infrared spectra will be the primary tool for finding and characterizing Earth-like planets around low-mass stars. Yet, the properties of exoplanets can not be precisely determined without accurate and precise measurements of the host star. Spectra obtained with the Immersion GRating INfrared Spectrometer (IGRINS) simultaneously provide diagnostics for most stellar parameters, but the first step in any analysis is the determination of the effective temperature. Here we report the calibration of high-resolution H-band spectra to accurately determine effective temperature for stars between 4000-3000 K ($\sim$K8--M5) using absorption line depths of Fe I, OH, and Al I. The field star sample used here contains 254 K and M stars with temperatures derived using BT-Settl synthetic spectra. We use 106 stars with precise temperatures in the literature to calibrate our method with typical errors of about 140 K, and systematic uncertainties less than $\sim$120 K. For the broadest applicability, we present T${}_{\mathrm{eff}}$--line-depth-ratio relationships, which we test on 12 members of the TW Hydrae Association and at spectral resolving powers between $\sim$10,000--120,000. These ratios offer a simple but accurate measure of effective temperature in cool stars that is distance and reddening independent.

19 pages, 11 figures and 3 tables. Accepted in ApJ

References in corpus (28)

• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
• Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes
• An Optical Spectroscopic Study of T Tauri Stars. I. Photospheric Properties
• Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters
• Planets Around Low-Mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems
• Activity and Kinematics of Ultracool Dwarfs Including An Amazing Flare Observation
• M dwarfs: effective temperatures, radii and metallicities
• A Stellar Census of the Tucana-Horologium Moving Group
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• Accurate fundamental parameters for Lower Main Sequence Stars
• High-Dispersion Optical Spectra of Nearby Stars Younger Than The Sun
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• First Results from the CHARA Array. IV. The Interferometric Radii of Low-Mass Stars
• Meeting the Cool Neighbors X: Ultracool dwarfs from the 2MASS All-Sky Data Release
• An empirical calibration to estimate cool dwarf fundamental parameters from H-band spectra
• Prospecting in Ultracool Dwarfs: Measuring the Metallicities of Mid- and Late-M Dwarfs
• A discontinuity in the $T_{\mathrm{eff}}$-radius relation of M-dwarfs
• The LuckyCam Survey for Very Low Mass Binaries II: 13 new M4.5-M6.0 Binaries
• Five new very low mass binaries
• A 3D Search for Companions to 12 Nearby M-Dwarfs
• A physically motivated and empirically calibrated method to measure effective temperature, metallicity, and Ti abundance of M dwarfs
• M dwarf luminosity, radius, and $\alpha$-enrichment from $I$-band spectral features
• Method to Estimate the Effective Temperatures of Late-Type Giants using Line-Depth Ratios in the Wavelength Range 0.97-1.32$\mu$m
• Deriving temperature, mass and age of evolved stars from high-resolution spectra. Application to field stars and the open cluster IC 4651
• Search for bright nearby M dwarfs with Virtual Observatory tools
• A Technique to Derive Improved Proper Motions for Kepler Objects of Interest

Cited by in corpus (13)

• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• Stellar Characterization of M-dwarfs from the APOGEE Survey: A Calibrator Sample for the M-dwarf Metallicities
• The IGRINS YSO Survey I. Stellar parameters of pre-main sequence stars in Taurus-Auriga
• Estimating fundamental parameters of nearby M dwarfs from SPIRou spectra
• Stellar Characterization and Radius Inflation of Hyades M Dwarf Stars From the APOGEE Survey
• The IGRINS YSO Survey III: Stellar parameters of pre-main sequence stars in Ophiuchus and Upper Scorpius
• Is T Tauri North a 'Classical' T Tauri star?
• Ultracool dwarfs identified using spectra in LAMOST DR7
• Effective Temperature Estimations from Line Depth Ratios in the \H\ and \K-band Spectra of IGRINS
• 10 Years of Archival High-Resolution NIR Spectra: The Raw and Reduced IGRINS Spectral Archive (RRISA)
• Chemical Compositions of Red Giant Stars in the Old Open Cluster NGC 7789
• 2MASS J04435686+3723033 B: A Young Companion at the Substellar Boundary with Potential Membership in the $\beta$ Pictoris Moving Group
• M dwarf spectral indices at moderate resolution: accurate $T_{\mathrm{eff}}$ and [Fe/H] for 178 southern stars