J/MNRAS/469/1783ivo://CDS.VizieR/J/MNRAS/469/1783doi:10.26093/cds/vizier.74691783CDSDuchene G.Becker A.Yang Y.Bouy H.De Rosa R.J.Patience J.,Girard J.H.2024-08-17T20:19:05Z2020-05-14T06:55:10ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsspectroscopyline-intensitiesWe conducted a 12-month monitoring campaign of 33 T Tauri stars (TTS) in Taurus. Our goal was to monitor objects that possess a disc but have a weak H{alpha} line, a common accretion tracer for young stars, in order to determine whether they host a passive circumstellar disc. We used medium-resolution optical spectroscopy to assess the accretion status of the objects and to measure the H{alpha} line. We found no convincing examples of passive discs: only transition disc and debris disc systems in our sample are non-accreting. Among accretors, we found no example of flickering accretion, leading to an upper limit of 2.2 per cent on the duty cycle of accretion gaps, assuming that all accreting TTS experience such events. When combining literature results with our observations, we found that the reliability of traditional H{alpha}-based criteria to test for accretion is high but imperfect, particularly for low-mass TTS. We found a significant correlation between stellar mass and the full width at 10 per cent of the peak (W_10_) of the H{alpha} line that does not seem to be related to variations in free-fall velocity. Finally, our data revealed a positive correlation between the H{alpha} equivalent width and its W_10_, indicative of a systematic modulation in the line profile whereby the high-velocity wings of the line are proportionally more enhanced than its core when the line luminosity increases. We argue that this supports the hypothesis that the mass accretion rate on the central star is correlated with the H{alpha} W_10_ through a common physical mechanism.2017MNRAS.469.1783Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/469/1783CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/312/439 : New T Tauri stars in Taurus-Auriga (Wichmann+, 1996)J/A+AS/132/173 : New weak-line T Tauri stars in Taurus-Auriga (Li+, 1998)J/A+A/519/A83 : T Tau stars toward the Taurus-Auriga region (Takita+, 2010)J/ApJS/216/26 : GALEX search for T Tauri in Taurus-Auriga (Gomez+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/469/1783https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/469/1783http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/469/1783https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/469/1783https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/469/1783http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/469/1783GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/469/1783/table1 (Observed sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/469/1783/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/469/1783/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/469/1783/table1?GETtext/xml+votable180.050000true70.320044228.66668810.0055555555555555566/1029 1031 1048 1050 1075 1081 1083 1123-1124 1156 1159 1168 1170-1171 23543 23549 23551 24300https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/469/1783?format=asciidefaultJ/MNRAS/469/1783/table1Observed sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSampleSample (1)src.samplecharNameObject namemeta.id;meta.maincharSpTypeSpectral type (2)src.spTypecharn_SpType[bd] Note on SpType (3)meta.notecharRmag? R magnitudemagphot.mag;em.opt.RfloatnullableEWHaH{alpha} equivalent width0.1nmspect.line.eqWidth;em.line.Halphafloatr_EWHaReference for EWHa (4)meta.ref;pos.frameintTTS[CW] Litterature classification, TTS (5)src.classcharUV[YN? -] Litterature classification, UV/veiling (6)meta.codecharSED[II/III ] Spectral energy distribution (2)meta.codecharn_SED[ac] Note on SED (3)meta.notecharAcc[Y/N? ] Accretor in this survey?meta.codecharMult[SBTQ] multiplicity flag (7)meta.code.multipcharNspecNumber of spectra obtained in this study, separated in time by a maximum of Dtmaxmeta.numberintDtmaxSeparation time for Nspecdtime.intervalint_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/469/1783/table3Spectral line measurementsl_EWLi[<>= ] Limit flag on EWLimeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTarget namemeta.id;meta.maincharDateObservation datetime.epoch;obsnullableNote[W] W for Weighted average (1)meta.notecharSNR? Signal-to-noise ratio estimated in the 6400-6700{AA} range, reported on a per resolution element basisstat.snrintnullableEWHaH{alpha} equivalent width0.1nmspect.line.eqWidth;em.line.HalphafloatE_EWHaError on Ha equivalent width (upper value)0.1nmstat.error;stat.maxfloate_EWHaError on Ha equivalent width (loper value)0.1nmstat.errorfloatl_W10[<>= ] Limit flag on W10meta.code.errorcharW10? H{alpha} full width at 10% of the fluxkm/sspect.line.widthintnullableE_W10? Error on W10 (upper value)km/sstat.error;stat.maxintnullablee_W10? Error on W10 (lower value)km/sstat.errorintnullableAsym[YN-] Asymetric profilemeta.codecharl_EWHeI5876[<>= ] Limit flag on EWHeI5876meta.code.errorcharEWHeI5876? HeI 5876 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWHeI5876? HeI 5876 equivalent width error0.1nmstat.errorfloatnullablel_EW[OI][<>= ] Limit flag on EW[OI]meta.code.error;spect.line.eqWidthcharEW[OI]? [OI]6300 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EW[OI]? [OI]6300 equivalent width error0.1nmstat.error;spect.line.eqWidthfloatnullablel_EWHeI6678[<>= ] Limit flag on EWHeI6678meta.code.errorcharEWHeI6678? HeI 6678 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWHeI6678? HeI 6678 equivalent width error0.1nmstat.errorfloatnullablel_EWCa8498[<>= ] Limit flag on EWCa8498meta.code.errorcharEWCa8498? Ca 8498 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWCa8498? Ca 8498 equivalent width error0.1nmstat.errorfloatnullablel_EWCa8542[<>= ] Limit flag on EWCa8542meta.code.errorcharEWCa8542? Ca 8542 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWCa8542? Ca 8542 equivalent width error0.1nmstat.errorfloatnullablel_EWCa8862[<>= ] Limit flag on EWCa8862meta.code.errorcharEWCa8862? Ca 8862 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWCa8862? Ca 8862 equivalent width error0.1nmstat.errorfloatnullableEWLi? Li 6707 equivalent width0.1nmspect.line.eqWidthfloatnullablee_EWLi? Li 6707 equivalent width error0.1nmstat.errorfloatnullableAcc[YN? -] Accretor status ? (see Section 4.5)meta.codechar