J/A+A/650/A190ivo://CDS.VizieR/J/A+A/650/A190doi:10.26093/cds/vizier.36500190CDSGonzalez-Payo J.Cortes-Contreras M.Lodieu N.Solano E.Zhang Z.H.,Galvez-Ortiz M.-C.2023-05-05T11:20:12Z2021-06-29T08:08:01ZCDS support team

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

cds-question@unistra.frmultiple-starssubdwarf-starsThe aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass metal-poor binaries and to improve the determination of their metallicity from the higher-mass binary. We made use of Virtual Observatory tools and large-scale public surveys to look in Gaia for common proper motion companions to a well-defined sample of ultracool subdwarfs with spectral types later than M5 and metallicities below or equal to ~0.5dex. We collected low-resolution optical spectroscopy for our best system, which is a binary composed of one sdM1.5 subdwarf and one sdM5.5 subdwarf located at ~1360au, and for another two likely systems separated by more than 115000au. We confirm one wide companion to an M subdwarf, and infer a multiplicity for M subdwarfs (sdMs) of 1.0_-1.0_^+2.0^% for projected physical separations of up to 743000au. We also find four M-L systems, three of which are new detections. No colder companion was identified in any of the 219 M and L subdwarfs of the sample, mainly because of limitations on the detection of faint sources with Gaia. We infer a frequency of wide systems for sdM5-9.5 of 0.60_-0.60_^+1.17^% for projected physical separations larger than 1360au (up to 142400au). This study shows a multiplicity rate of 1.0_-1.0_^+2.0^% in sdMs, and 1.9_-1.9_^+3.7^% in extreme M subdwarfs. We did not find any companion for the ultra M subdwarfs of our sample, establishing an upper limit of 5.3% on binarity for these objects.2021A&A...650A.190Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/650/A190CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/650/A190https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/650/A190http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/650/A190https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/650/A190https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/650/A190http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/650/A190GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/650/A190/tablea1 (Properties of all subdwarfs in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/650/A190/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/650/A190/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/650/A190/tablea1?GETtext/xml+votable180.050000true1.43820837.39508330.005555555555555556Cone search capability for table J/A+A/650/A190/tablea3 (Astrometric data of the companion candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/650/A190/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/650/A190/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/650/A190/tablea3?GETtext/xml+votable180.050000true19.8896253.55438890.0055555555555555565/4552 6/128 544 3965 4099 4142 4157 4245 4352 4465 4521 4661 4784 5017 5027 5095 5140-5141 5222 5238 5326 5344 5563 5691 6169 6230 6241 6423 6441 6450 6476 7181 7443 7536-7538 8194 8230 8234 8292 8395 8405 8521 8713 8719 8783 8895 8912 9087 9136 9145 9244 9315 9325 9377 9467 9607 9792 10250 10266 10294 10337 10354 10363 10389 10409 10429 10447 10567 10569 10710 10770 10828 10899 11054 11095 11271 11329 11404 11444 11448 11665 11848 12066 13952 15494 16800 17268 17661 17778 17856 17864 17907 18097 18204 18381 18389 18802 18805 18858 18888 18907 19249 19283 19286 19289 19292 19317 19319 19511 19525 19727-19728 19765 19778 19906 20000 20672 21156 21845 21977 22003 23196 24213 24338 25582 25845 25916 25936 25947 25962 25965 26032-26033 26042 26055 26186 26194 26211 26216 26261-26262 26271 26325 26330 26396 26410 26412 26438 26446 26471 26497 26515 26537 26539 26559 26567 26602 26667 26807 26900 26988 27019 27038 27084 27110 27116 27132 27211 27253 27294 27334 27393 27410 27441 27460 27470 27508 27517-27518 27579 27588 27666 27668 27685 27702 27721 27779 27828 27886 27904 27921 27925 27933 27941 27968 27971-27972 27974 27980 28000 28139 28156 28342 28409 28656 30037 31293 31309 31338 31386 31393 31397 31426 31434 31456 31460 31599 31696 32574 34239 37519 38915 44349 44632 47357 47866https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/650/A190?format=asciidefaultJ/A+A/650/A190/tablea1Properties of all subdwarfs in the sampleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/219] Number of the subdwarf inside the samplemeta.numberintNameDenomination of the subdwarf in the cataloguesmeta.id;meta.maincharRAJ2000Right ascension of the subdwarf (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination of the subdwarf (J2000) (1)pos.eq.dec;meta.mainGaiaDR2? Identification number of the subdwarf in Gaia DR2 cataloguemeta.idnullableSpTypeSpectral type of the subdwarfsrc.spTypecharRefLiterature reference for the above data per subdwarf (2)meta.ref;pos.framecharJ/A+A/650/A190/tablea2Astrometric data of the subdwarfsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/219] Number of the subdwarf inside the samplemeta.numberintpmRASubdwarf proper motion, RA component, pmRA*cosDEmas/yrpos.pm;pos.eq.radoublee_pmRArms uncertainty on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDESubdwarf proper motion, DE componentmas/yrpos.pm;pos.eq.decdoublee_pmDErms uncertainty on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatr_pmOrigin of the value used in the work (Gaia DR2 or calculated by us)meta.ref;pos.framecharDistDistance to the subdwarfpcpos.distancefloate_Distrms uncertainty on Distancepcstat.errorfloatr_DistOrigin of the value of the distance used in the work (Gaia DR2 or calculated by us)meta.ref;pos.framecharRadSearchRadius for searching for possible candidates to companionsdegphys.angSizefloatJ/A+A/650/A190/tablea3Astrometric data of the companion candidatesSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountpos.eq.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCandIdNumber YY of the possible candidate to companion in relation to the XXX subdwarf: XXX-YYmeta.id;meta.maincharGaiaDR2Identification number of the companion in Gaia DR2 cataloguemeta.idRA_ICRSRight ascension of the companion candidate (ICRS) at Ep=2015.5pos.eq.ra;meta.mainDE_ICRSDeclination of the companion candidate (ICRS) at Ep=2015.5pos.eq.dec;meta.mainpmRACandidate proper motion, RA component, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRArms uncertainty on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDECandidate proper motion, DE componentmas/yrpos.pm;pos.eq.decfloate_pmDErms uncertainty on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatDistDistance of the companion candidatepcpos.distancefloate_Distrms uncertainty on Distancepcstat.errorfloatSepSeparation between subdwarf and companion candidatearcminpos.angDistancefloatn_Sep[a] a: Distance is in arcsecmeta.notechar