J/A+A/312/439ivo://CDS.VizieR/J/A+A/312/439doi:10.26093/cds/vizier.33120439CDSWichmann R.Krautter J.Schmitt J.H.M.M.Neuhauser R.Alcala J.M.,Zinnecker H.Wagner R.M.Mundt R.Sterzik M.F.2025-04-16T20:00:07Z1999-07-29T16:25:48ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsx-ray-sourcesOn the basis of the ROSAT All-Sky-Survey, a study of the Taurus-Auriga star forming region has been performed in order to search for hitherto undiscovered T Tauri stars. Our study covers an area of about 280 square degrees, located between 4^h^ and 5^h^ in right ascension and between 15deg and 34deg in declination. Identification of ROSAT All-Sky Survey sources in this area by means of optical spectroscopy revealed 2 new classical T Tauri stars (CTTS) and 66 new weak-line-T Tauri stars (WTTS) with W_{lambda}_(H{alpha})<=10A. Additional pointed ROSAT observations led to the identification of 6 more WTTS and 2 CTTS, giving a total of 76 new T Tauri stars. The large area of our study, as compared with previous works, allows us to study the spatial distribution of WTTS in this star forming region. We find the WTTS of our survey to be distributed over the whole region investigated. There is a noticeable decline of the surface density from south to north within our study area, but the spatial distribution extends most probably beyond our study region. No clustering towards the population of T Tauri stars known prior to ROSAT in Taurus-Auriga could be observed. We suggest that the WTTS found in our study might in part be somewhat older than the previously known T Tauri stars in Taurus-Auriga, and that their broad spatial distribution is due to the typical velocity dispersion of a few km/s measured for Taurus T Tauri stars, in which case for some of our WTTS an age on the order of 10^7^years would be required for reaching the observed distances from the Taurus dark clouds. We estimate a WTTS/CTTS ratio of about 6 within our study area, but conclude that because of the different spatial distribution of WTTS and CTTS this ratio will be most probably significantly larger for a more extended area.1996A&A...312..439Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/312/439CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/297/391 : T Tauri stars ROSAT survey (Neuhaeuser+, 1995)J/A+AS/132/173 : New weak-line T Tauri stars in Taurus-Auriga (Li+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/312/439https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/312/439http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/312/439https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/312/439https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/312/439http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/312/439GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/312/439/table4 (New T Tauri stars in Taurus-Auriga)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/312/439/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/312/439/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/312/439/table4?GETtext/xml+votable180.050000true60.129519.58908330.005555555555555556Cone search capability for table J/A+A/312/439/table5 (Non-TTS emission-line stars found in the course of our survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/312/439/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/312/439/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/312/439/table5?GETtext/xml+votable180.050000true60.97666724.7893060.005555555555555556Cone search capability for table J/A+A/312/439/table7 (X-ray sources in pointed observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/312/439/table7?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/312/439/table7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/312/439/table7?GETtext/xml+votable180.050000true63.84820.73772220.005555555555555556ROSAT5/87 5887 6/324 326-327 331-333 338 340-342 347 358 368 374 380-381 469 1025 1027 1030 1036 1039 1042 1048 1055 1057 1065-1067 1069 1077 1079-1080 1082-1083 1098-1099 1103 1114-1115 1120 1130 1134 1137-1138 1140 1146 1148 1152 1155 1165 1168-1169 1172 1174 1180-1182 1205 1207 1212 1232 23507 23510 23514 23517-23518 23532-23533 23542-23543 24105 24107 24192-24193 24195-24197 24204-24205 24207 24219 24222 24229-24232 24234 24237-24238 24242 24246 24249-24251https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/312/439?format=asciiX-raydefaultJ/A+A/312/439/table4New T Tauri stars in Taurus-AurigarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoNumbermeta.idintNameIdentifier of star (1)meta.id;meta.maincharn_Pos[X] Note on position (2)meta.notecharn_Xray[P] Note on X-ray detection (3)meta.notecharRAJ2000Right Ascension for equinox J2000.0pos.eq.ra;meta.mainDEJ2000Declination for equinox J2000.0pos.eq.dec;meta.mainEW(Ha)Equivalent width for H_alpha0.1nmspect.line.eqWidthfloatSpSpectral typesrc.spTypecharPmagMagnitude as listed in the Hubble GSC (4)magphot.mag;em.optfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/312/439/table5Non-TTS emission-line stars found in the course of our surveySimbadSimbad column added by the CDSmeta.ref.urlcharNameIdentifier of starmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_Pos[X] Note on position (1)meta.notecharn_Xray[P] Note on X-ray detection (2)meta.notecharRAJ2000Right Ascension for equinox J2000.0pos.eq.ra;meta.mainDEJ2000Declination for equinox J2000.0pos.eq.dec;meta.mainCRBackground subtracted X-ray count rate (0.1-2.4keV energy range)s**-1phot.count;em.X-rayfloate_CRError in CRs**-1stat.errorfloatSpSpectral typesrc.spTypecharEW(Ha)Equivalent width for H_alpha0.1nmspect.line.eqWidthfloatJ/A+A/312/439/table6ROSAT X-ray data and spectral fit results for new T Tauri starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE_LXPositive error for LX1e+23Wstat.error;stat.maxfloate_LXNegative error for LX1e+23Wstat.errorfloatNameIdentifier of starmeta.id;meta.maincharn_Pos[P] Note on X-ray data (1)meta.notecharMLMaximum likelihood of existencestat.likelihoodfloatCtsBackground subtracted X-ray counts (0.1 to 2.4 keV energy range)phot.count;em.X-rayfloate_CtsErrors for X-ray countsstat.errorfloatExpExposure timestime.expofloatHR1Hardness ratio 1phot.flux;arith.ratiofloate_HR1Error in hardness ratio 1stat.errorfloatHR2Hardness ratio 2phot.flux;arith.ratiofloate_HR2Error in hardness ratio 2stat.errorfloatlog(NH)Logarithm of HI column density (2)log(cm**-2)phys.columnDensityfloatE_log(NH)Positive error for log(NH)log(cm**-2)stat.error;stat.maxfloate_log(NH)Negative error for log(NH)log(cm**-2)stat.errorfloatTXTemperature (2)keVphys.temperaturefloatE_TXPositive error for TXkeVstat.error;stat.maxfloate_TXNegative error for TXkeVstat.errorfloatLXX-ray luminosity (10^30^erg/s) (3)1e+23Wphys.luminosity;em.X-rayfloatJ/A+A/312/439/table7X-ray sources in pointed observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIdentifier of starmeta.id;meta.maincharRAJ2000Right Ascension for equinox J2000.0pos.eq.ra;meta.mainDEJ2000Declination for equinox J2000.0pos.eq.dec;meta.mainCtsBackground subtracted X-ray count rate (0.1-2.4 keV energy range)s**-1phot.count;em.X-rayfloate_CtsError in X-ray count rates**-1stat.errorfloatHR1Hardness Ratio 1phot.flux;arith.ratiofloate_HR1Error in Hardness Ratio 1stat.errorfloatHR2Hardness Ratio 2phot.flux;arith.ratiofloate_HR2Error in Hardness Ratio 2stat.errorfloat