The AstraLux Multiplicity Survey: Extension to Late M-dwarfs

Abstract

The distribution of multiplicity among low-mass stars is a key issue to understanding the formation of stars and brown dwarfs, and recent surveys have yielded large enough samples of nearby low-mass stars to study this issue statistically to good accuracy. Previously, we have presented a multiplicity study of ~700 early/mid M-type stars observed with the AstraLux high-resolution Lucky Imaging cameras. Here, we extend the study of multiplicity in M-type stars through studying 286 nearby mid/late M-type stars, bridging the gap between our previous study and multiplicity studies of brown dwarfs. Most of the targets have been observed more than once, allowing us to assess common proper motion to confirm companionship. We detect 68 confirmed or probable companions in 66 systems, of which 41 were previously undiscovered. Detections are made down to the resolution limit of ~100 mas of the instrument. The raw multiplicity in the AstraLux sensitivity range is 17.9%, leading to a total multiplicity fraction of 21-27% depending on the mass ratio distribution, which is consistent with being flat down to mass ratios of ~0.4, but cannot be stringently constrained below this value. The semi-major axis distribution is well represented by a log-normal function with mu_a = 0.78 and sigma_a = 0.47, which is narrower and peaked at smaller separations than for a Sun-like sample. This is consistent with a steady decrease in average semi-major axis from the highest-mass binary stars to the brown dwarf binaries.

28 pages, 7 figures, ApJ accepted. V2: Minor corrections; reformulated G91 parallax reference (thanks to J. Winters) and corrected one line in table 3

References in corpus (16)

• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m Program -- Twenty New Members of the RECONS 10 Parsec Sample
• The Gemini Deep Planet Survey -- GDPS
• Meeting the Cool Neighbors X: Ultracool dwarfs from the 2MASS All-Sky Data Release
• Deficit of wide binaries in the eta Chamaeleontis young cluster
• Discovery of 9 New Companions to Nearby Young M Stars with the Altair AO System
• New Neighbors: Parallaxes of 18 nearby stars selected from the LSPM-north catalog
• Dynamical Mass of GJ 802B: a brown dwarf in a triple system
• Southern wide very low-mass stars and brown dwarfs in resolved binary and multiple systems
• X-Ray-Emitting Stars Identified from the ROSAT All-Sky Survey and the Sloan Digital Sky Survey
• Orbits and Masses in the T Tauri System
• The LuckyCam Survey for Very Low Mass Binaries II: 13 new M4.5-M6.0 Binaries
• Five new very low mass binaries
• Masses of Astrometrically-Discovered and Imaged Binaries: G 78-28AB and GJ 231.1BC
• The Detection of Low Mass Companions in Hyades Cluster Spectroscopic Binary Stars
• Improved age constraints for the AB Dor quadruple system - The binary nature of AB Dor B

Cited by in corpus (31)

• How to Constrain Your M Dwarf: measuring effective temperature, bolometric luminosity, mass, and radius
• The Solar Neighborhood XLV. The Stellar Multiplicity Rate of M Dwarfs Within 25 pc
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• The Solar Neighborhood XXXV: Distances to 1404 M Dwarf Systems Within 25 pc in the Southern Sky
• A giant exoplanet orbiting a very low-mass star challenges planet formation models
• CARMENES input catalogue of M dwarfs II. High-resolution imaging with FastCam
• The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0-T8 dwarfs with UKIRT
• Characterizing the Brown Dwarf Formation Channels from the Initial Mass Function and Binary-star Dynamics
• Characterizing Undetected Stellar Companions with Combined Datasets
• The Origin of the Stellar Mass Distribution and Multiplicity
• The Volume-Complete Sample of M Dwarfs with Masses 0.1 <= M/M_sol <= 0.3 within 15 Parsecs
• The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-Rich Stars in the Solar Neighborhood
• Orbital Monitoring of the AstraLux Large M-dwarf Multiplicity Sample
• Binaries among low-mass stars in nearby young moving groups
• The CARMENES search for exoplanets around M dwarfs, Wolf 1069 b: Earth-mass planet in the habitable zone of a nearby, very low-mass star
• BEAST begins: Sample characteristics and survey performance of the B-star Exoplanet Abundance Study
• The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393
• Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaboration
• Detecting New Visual Binaries in Gaia DR3 with Gaia and 2MASS Photometry I. New Candidate Binaries Within 200 pc of the Sun
• Stellar activity with LAMOST. III. Temporal variability pattern in Pleiades, Praesepe, and Hyades
• Updated orbital monitoring and dynamical masses for nearby M-dwarf binaries
• Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes
• Spectral characterization of newly detected young substellar binaries with SINFONI
• Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program
• One is the loneliest number: multiplicity in cool dwarfs
• Characterising Young Visual M-dwarf Binaries with Near-Infrared Integral Field Spectra
• Radio Emission from a Nearby M dwarf Binary
• Detection and characterisation of two VLM binaries: LP 1033-31 and LP 877-72
• Constraints on the Spindown of Fully-Convective M Dwarfs Using Wide Field Binaries
• TOI-1201 b: A mini-Neptune transiting a bright and moderately young M dwarf
• Discovery of 34 low-mass comoving systems using NOIRLab Source Catalog DR2