J/A+A/678/A161ivo://CDS.VizieR/J/A+A/678/A161doi:10.26093/cds/vizier.36780161CDSGloudemans A.J.Callingham J.R.Duncan K.J.Saxena A.Harikane Y.,Hill G.J.Zeimann G.R.Rottgering H.J.A.Hardcastle M.J.Pineda J.S.,Shimwell T.W.Smith D.J.B.Wagenveld J.D.2024-11-28T20:05:23Z2023-10-17T15:51:33ZCDS support team

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

cds-question@unistra.frm-starsradio-continuum-emissionvisible-astronomyspectroscopyWe present the serendipitous discovery of 8 distant (>50pc) late M dwarfs with plausible associated radio emission at 144MHz. The M dwarf nature of our sources has been confirmed with optical spectroscopy performed using HET/LRS2 and Subaru/FOCAS, and their radio flux densities are within the range of 0.5-1.0mJy at 144MHz. Considering the radio-optical source separation and source densities of the parent catalogues, we suggest that it is statistically probable the M dwarfs are associated with the radio emission. However, it remains plausible that for some of the sources the radio emission originates from an optically faint and red galaxy hiding behind the M dwarf. The isotropic radio luminosities (~10^17-18^erg/s/Hz) of the M dwarfs suggest that if the association is real, the radio emission is likely driven by a coherent emission process produced via plasma or electron-cyclotron maser instability processes, which is potentially caused by binary interaction. Long term monitoring in the radio and high-resolution radio follow-up observations are necessary to search for any variability and pinpoint the radio emission to determine whether our tentative conclusion that these ultracool dwarfs are radio emitting is correct. If the low-frequency radio emission is conclusively associated with the M dwarfs, this would reveal a new population of optically faint and distant (>50pc) radio emitting M dwarfs.2023A&A...678A.161Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A161CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A161https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A161http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A161https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A161https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A161http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A161GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/678/A161/table2 (Measurements of M dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A161/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A161/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A161/table2?GETtext/xml+votable180.050000true2.536442823932.65032925840.005555555555555556Cone search capability for table J/A+A/678/A161/list (List of spectra fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A161/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A161/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A161/list?GETtext/xml+votable180.050000true2.536442823932.65032925840.0055555555555555566/5310 5399 5958 6082 6271 7502 20421 327639.54153977050123e-26 9.54153977050123e-26https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/678/A161?format=asciiOpticalRadiodefaultJ/A+A/678/A161/table2Measurements of M dwarfsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintspShow the spectrummeta.ref.urlcharNameSource name (ILTJJJMM+DDMM)meta.id;meta.maincharRAJ2000Right ascension Legacy Surveys DR8 (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination Legacy Surveys DR8 (J2000.0)degpos.eq.dec;meta.mainRALdegRight ascension from LoTSS-DR2 (J2000.0)degpos.eq.raDELdegDeclination from LoTSS-DR2 (J2000.0)degpos.eq.decSepSeparation between optical and radio sourcearcsecpos.angDistancefloatF144MHzTotal flux at 144MHzmJyphot.flux.density;em.radio.100-200MHzfloate_F144MHzTotal flux error at 144MHzmJystat.errorfloatzmagLegacy z-band magnitudemagphot.mag;em.opt.Ifloate_zmagLegacy z-band magnitude errormagstat.error;phot.magfloatJmag? UHS J-band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? UHS J-band magnitude errormagstat.error;phot.magfloatnullableJ/A+A/678/A161/listList of spectra fits filesNameSource namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainObs.dateObservations date (dd-mm-yyyy)time.epoch;obsnullableInstName of instrumentmeta.id;instrcharTelName of telescopemeta.id;instr.telcharFilenameName of FITS file in subdirectory fitsmeta.id;meta.fitscharspShow the spectrummeta.ref.urlchar