J/A+A/600/A19ivo://CDS.VizieR/J/A+A/600/A19doi:10.26093/cds/vizier.36000019CDSPhan-Bao N.Bessell M.S.Nguyen-Thanh D.Martin E.L.Ho P.T.P.,Lee C.F.Parsons H.2017-04-11T09:17:28Z2017-03-21T13:54:25ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frm-starsspectroscopyLate M-type dwarfs in the solar neighborhood include a mixture of very low-mass stars and brown dwarfs that is difficult to disentangle due to the lack of constraints on their age, such as trigonometric parallax, lithium detection, and space velocity. We search for young brown dwarf candidates among a sample of 28 nearby late-M dwarfs with spectral types between M5.0 and M9.0, and we also search for debris disks around three of them. Based on theoretical models, we used the color I-J, the J-band absolute magnitude, and the detection of the LiI 6708{AA} doublet line as a strong constraint to estimate masses and ages of our targets. For the search of debris disks, we observed three targets at submillimeter wavelength of 850um. We report here the first clear detections of lithium absorption in four targets and a marginal detection in one target. Our mass estimates indicate that two of them are young brown dwarfs, two are young brown dwarf candidates, and one is a young very low-mass star. The closest young field brown dwarf in our sample at only ~15pc is an excellent benchmark for further studying physical properties of brown dwarfs in the range 100-150Myr. We did not detect any debris disks around three late-M dwarfs, and we estimated upper limits to the dust mass of debris disks around them.2017A&A...600A..19Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/600/A19CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/denis : The DENIS database (DENIS Consortium, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/600/A19https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/600/A19http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/600/A19https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/600/A19https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/600/A19http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/600/A19GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/600/A19/table1 (H{alpha}, Li I 6708{AA} and Na I (8170-8200{AA}) equivalent widths of 28 nearby late-M dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/600/A19/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/600/A19/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/600/A19/table1?GETtext/xml+votable180.050000true10.3974569-56.35358690.0055555555555555566/18979 18999 22657 22739 23144 24657 30903 32830 33655 34289 34301 34961 35008 35203 37678 40623 43413 44318 44778 44881 45344 45576 45626 45752 45963 45994 48025 48735https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/600/A19?format=asciiOpticaldefaultJ/A+A/600/A19/table1H{alpha}, Li I 6708{AA} and Na I (8170-8200{AA}) equivalent widths of 28 nearby late-M dwarfsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDENIS-PDENIS-P name (JHHMMSS+DDMMSS) (Cat. B/denis)meta.id;meta.maincharn_DENIS-P[a] Note on DENIS-P (1)meta.notecharONameOther namemeta.idcharn_OName[bcd] Note on ONAme (1)meta.notecharSpTypeMK spectral typesrc.spTypecharDistDistancepcpos.distance;pos.heliocentricfloate_Distrms uncertainty on Distpcstat.errorfloatObs.dateUT observing datetime.epochnullablel_EWHaLimit flag on EWmeta.code.errorcharEWHaH{alpha} equivalent width (2)0.1nmspect.line.eqWidth;em.line.Halphafloate_EWHa? rms uncertainty on EWHa0.1nmstat.errorfloatnullablel_EWLiLimit flag on EWLimeta.code.errorcharEWLiLithium equivalent width (2)0.1nmspect.line.eqWidthfloate_EWLi? rms uncertainty on EWLi0.1nmstat.errorfloatnullablen_EWLi[e] Note on EWLi (1)meta.notecharEWNaI? NaI equivalent width (3)0.1nmspect.line.eqWidthfloatnullablee_EWNaI? rms uncertainty on EWNaI0.1nmstat.errorfloatnullableRefReferences for spectral type and distance (4)meta.refintspShow the spectrummeta.ref.urlcharFileNameName of the fits spectrum file in subdirectory fitsmeta.id;meta.fitschar_RAPositions from DENIS (B/denis) catalog (right ascension part)degpos.eq.ra;meta.main_DEPositions from DENIS (B/denis) catalog (declination part)degpos.eq.dec;meta.main