Discovery of new nearby L and late-M dwarfs at low Galactic latitude from the DENIS database

Abstract

We report new nearby L and late-M dwarfs (d_phot <= 30 pc) discovered in our search for nearby ultracool dwarfs (I-J >= 3.0, later than M8.0) at low Galactic latitude (|b| < 15 degr) over 4,800 square degrees in the DENIS database. We used late-M (>=M8.0), L, and T dwarfs with accurate trigonometric parallaxes to calibrate the M_J versus I-J colour-luminosity relation. The resulting photometric distances have standard errors of ~15%, which we used to select candidates d_phot <= 30 pc. We measured proper motions from multi-epoch images found in the public archives ALADIN, DSS, 2MASS, DENIS, with at least three distinct epochs and time baselines of 10 to 21 years. We then used a Maximum Reduced Proper Motion cutoff to select 28 candidates as ultracool dwarfs (M8.0--L8.0) and to reject one as a distant red star. No T dwarf candidates were found in this search which required an object to be detected in all three DENIS bands. Our low-resolution optical spectra confirmed that 26 of them were indeed ultracool dwarfs, with spectral types from M8.0 to L5.5. Two contaminants and one rejected by the Maximum Reduced Proper Motion cutoff were all reddened F-K main sequence stars. 20 of these 26 ultracool dwarfs are new nearby ultracool dwarf members, three L dwarfs within 15 pc with one L3.5 at only ~10 pc. We determine a stellar density of \barΦ_J cor=(1.64 +- 0.46).10^{-3} dwarfs pc^{-3} mag^{-1} over 11.1 <= M_J <= 13.1 based on that sample of M8--L3.5 ultracool dwarfs. Our ultracool dwarf density value is in good agreement with the Cruz et al. measurement of the ultracool dwarf density at high Galactic latitude.

arXiv comment17 pages, 11 figures, 7 tables, accepted by MNRAS

References in corpus (52)

• The Sloan Digital Sky Survey: Technical Summary
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• Color Transformations for the 2MASS Second Incremental Data Release
• Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs
• Sixty-seven Additional L Dwarfs Discovered by the Two Micron All Sky Survey (2MASS)
• Near-Infrared Photometry and Spectroscopy of L and T Dwarfs: the Effects of Temperature, Clouds, and Gravity
• New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
• Towards Spectral Classification of L and T Dwarfs: Infrared and Optical Spectroscopy and Analysis
• Preliminary Parallaxes of 40 L and T Dwarfs from the U.S. Naval Observatory Infrared Astrometry Program
• The Spectra of T Dwarfs I: Near-Infrared Data and Spectral Classification
• Meeting the Cool New Neighbors V: A 2MASS-Selected Sample of Ultracool Dwarfs
• Binarity in Brown Dwarfs: T Dwarf Binaries Discovered with the Hubble Space Telescope WPFC2
• Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
• The 2MASS Wide-Field T Dwarf Search. III. Seven New T Dwarfs and Other Cool Dwarf Discoveries
• Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey
• Multiplicity of Nearby Free-floating Ultra-cool Dwarfs: a HST-WFPC2 search for companions
• Meeting the Cool Neighbors. IX. The Luminosity Function of M7-L8 Ultracool Dwarfs in the Field
• Infrared Spectra and Spectral Energy Distributions of Late-M- and L-Dwarfs
• Activity in Very Cool Stars: Magnetic Dissipation in late-M and L Dwarf Atmospheres
• A search for L dwarf binary systems
• Hubble Space Telescope Observations of Binary Very-Low-Mass Stars and Brown Dwarfs
• Four nearby L dwarfs
• Epsilon Indi Ba/Bb: the nearest binary brown dwarf
• SDSS J1534+1615AB: A Novel T Dwarf Binary Found with Keck Laser Guide Star Adaptive Optics and the Potential Role of Binarity in the L/T Transition
• L Dwarfs Found in Sloan Digital Sky Survey Commissioning Imaging Data
• A search for binary systems among the nearest L dwarfs
• Infrared Colors at the Stellar/Substellar Boundary
• JHK Magnitudes for L and T Dwarfs and Infrared Photometric Systems
• Epsilon Indi B: a new benchmark T dwarf
• Meeting the Cool Neighbors III: Spectroscopy of Northern NLTT Stars
• New High Proper Motion Stars from the Digitized Sky Survey. I. Northern Stars with proper motion between 0.5 and 2.0 arcsec/yr at Low Galactic Latitudes
• Optical Spectroscopy of 2MASS Color-Selected Ultracool Subdwarfs
• Meeting the Cool Neighbours I: Nearby stars in the NLTT Catalogue - Defining the sample
• Keck Imaging of Binary L Dwarfs
• Eight new T4.5-T7.5 dwarfs discovered in the UKIDSS Large Area Survey Data Release 1
• The Solar Neighborhood IX: Hubble Space Telescope Detections of Companions to Five M and L Dwarfs within 10 pc of the Sun
• Dust in the Photospheric Environment III. A Fundamental Element in the Characterization of Ultracool Dwarfs
• Spectroscopic classification of red high proper motion objects in the Southern Sky
• Southern Infrared Proper Motion Survey I: Discovery of New High Proper Motion Stars From First Full Hemisphere Scan
• Discovery of a High Proper Motion L Dwarf Binary: 2MASS J15200224-4422419AB
• A Systematic Study Of X-Ray Variability In The ROSAT All-Sky Survey
• New, nearby bright southern ultracool dwarfs
• New neighbours: IV. 30 DENIS late-M dwarfs between 15 and 30 parsecs
• Discovery of a nearby L-T transition object in the Southern Galactic plane
• New neighbours: V. 35 DENIS late-M dwarfs between 10 and 30 parsecs
• New neighbours VI. Spectroscopy of DENIS nearby stars candidates
• SSSPMJ0829-1309: A new nearby L dwarf detected in SuperCOSMOS Sky Surveys
• LSR0602+3910 - Discovery of a Bright Nearby L-type Brown Dwarf
• Spectroscopic distances of nearby ultracool dwarfs
• A new strongly X-ray flaring M9 dwarf in the solar neighborhood
• New nearby stars selected in a high proper motion survey by DENIS photometry
• Meeting the Cool Neighbours, VI: A search for nearby ultracool dwarfs in the Galactic Plane

Cited by in corpus (60)

• Target Selection for the Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime
• The Brown Dwarf Kinematics Project (BDKP) I. Proper Motions and Tangential Velocities for a Large Sample of Late-type M, L and T Dwarfs
• Population Properties of Brown Dwarf Analogs to Exoplanets
• BANYAN. VII. A New Population of Young Substellar Candidate Members of Nearby Moving Groups from the BASS Survey
• The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
• The Solar Neighborhood XXXII. The Hydrogen Burning Limit
• SpeX Spectroscopy of Unresolved Very Low Mass Binaries. II. Identification of Fourteen Candidate Binaries with Late-M/Early-L and T Dwarf Components
• Preliminary Trigonometric Parallaxes of 184 Late-T and Y Dwarfs and an Analysis of the Field Substellar Mass Function into the "Planetary" Mass Regime
• BANYAN. XIII. A First Look at Nearby Young Associations with Gaia Data Release 2
• Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3$\pi$ Survey
• A Volume-Limited Sample of Ultracool Dwarfs. I. Construction, Space Density, and a Gap in the L/T Transition
• Doppler Imaging of Exoplanets and Brown Dwarfs
• The lithium depletion boundary and the age of the Hyades cluster
• Wide, Cool and Ultracool Companions to Nearby Stars from Pan-STARRS1
• The Brown Dwarf Kinematics Project (BDKP). IV. Radial Velocities of 85 Late-M and L dwarfs with MagE
• The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0-T8 dwarfs with UKIRT
• Spectroscopic characterization of 78 DENIS ultracool dwarf candidates in the solar neighborhood and the Upper Sco OB association
• An Infrared High Proper Motion Survey Using 2MASS and SDSS: Discovery of M, L and T Dwarfs
• Astrometric orbit of a low-mass companion to an ultracool dwarf
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• Near-infrared low-resolution spectroscopy of Pleiades L-type brown dwarfs
• The Ultracool SpeXtroscopic Survey. I. Volume-Limited Spectroscopic Sample and Luminosity Function of M7$-$L5 Ultracool Dwarfs
• Astrometric planet search around southern ultracool dwarfs I: First results, including parallaxes of 20 M8-L2 dwarfs
• Neighbours hiding in the Galactic plane - a new M/L dwarf candidate for the 8pc sample
• Intermediate Resolution Near-Infrared Spectroscopy of 36 late-M Dwarfs
• Discovery of the first wide L dwarf + giant binary system and eight other ultra-cool dwarfs in wide binaries
• The Solar Neighborhood XXIII CCD Photometric Distance Estimates of SCR Targets -- 77 M Dwarf Systems within 25 Parsecs
• One more neighbor: The first brown dwarf in the VVV survey
• Identifying Ultra-Cool Dwarfs at Low Galactic Latitudes: A Southern Candidate Catalogue
• WISEP J180026.60+013453.1: A Nearby Late L Dwarf Near the Galactic Plane
• Extremely faint high proper motion objects from SDSS stripe 82 - Optical classification spectroscopy of about 40 new objects
• VIRAC2: NIR Astrometry and Time Series Photometry for 500M+ Stars from the VVV and VVVX Surveys
• Constraints on the binary Properties of mid to late T dwarfs from Hubble Space Telescope WFC3 Observations
• Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. IV. Discovery of an M9 + L6 BInary Separated by Over 100 AU
• High Proper Motion Objects from the UKIDSS Galactic Plane Survey
• Binarity at the L/T brown dwarf transition
• Astrometric planet search around southern ultracool dwarfs III. Discovery of a brown dwarf in a 3-year orbit around DE0630-18
• Discovery And Characterization of Wide Binary Systems With a Very Low Mass Component
• The ChaMPlane bright X-ray sources - Galactic longitudes l = 2-358 deg
• X-ray emission from the M9 dwarf 1RXS J115928.5-524717 - Quasi-quiescent coronal activity at the end of the main sequence
• On the Correlation between L Dwarf Optical and Infrared Variability and Radio Aurorae
• Optical Spectra of Ultracool Dwarfs with the Southern African Large Telescope
• Detection of lithium in nearby young late-M dwarfs
• DE0823$-$49 is a juvenile binary brown dwarf at 20.7 pc
• Individual Dynamical Masses of DENIS J063001.4$-$184014AB Reveal A Likely Young Brown Dwarf Triple
• Increasing the census of L and T dwarfs in wide binary and multiple systems using Dark Energy Survey DR1 and Gaia DR2 data
• VVVX near-IR photometry for 99 low-mass stars in the Gaia EDR3 Catalog of Nearby Stars
• New ultracool dwarf candidates from multi-epoch WISE data
• Maximum Reduced Proper Motion Method: Detection of New Nearby Ultracool Dwarfs
• Large Scale Searches for Brown Dwarfs and Free-Floating Planets
• CaII and H$\alpha$ flaring M dwarfs detected with multi-filter photometry
• Low-resolution near-infrared spectroscopic signatures of unresolved ultracool companions to M dwarfs
• The Brown Dwarf Kinematics Project (BDKP). II. Details on Nine Wide Common Proper Motion Very Low-Mass Companions to Nearby Stars
• The Brown Dwarf Kinematics Project (BDKP). V. Radial and Rotational Velocities of T Dwarfs from Keck/NIRSPEC High-Resolution Spectroscopy
• The Gaia Ultracool Dwarf Sample -- IV. GTC/OSIRIS optical spectra of Gaia late-M and L dwarfs
• Silicate Clouds, SiO, and Molecular Trends across the L-T Sequence: A JWST/MIRI LRS Spectral Library of Brown Dwarfs
• Using Old and New Approaches: Determining Physical Properties of Brown Dwarfs with Empirical Relations and Machine Learning Models
• Astrometric planet search around southern ultracool dwarfs IV. Relative motion of the FORS2/VLT CCD chips
• New constraints on the minimum mass for thermonuclear lithium burning in brown dwarfs