J/ApJ/875/51ivo://CDS.VizieR/J/ApJ/875/51doi:10.26093/cds/vizier.18750051CDSBiazzo K.Beccari G.De Marchi G.Panagia N.2022-07-08T07:27:07Z2020-10-07T14:53:32ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsaccretionpre-main-sequence-starshst-photometryinfrared-photometryvisible-astronomyphotometryh-alpha-photometrystellar-associationsstellar-massesstellar-agesWe report on the accretion properties of low-mass stars in the LH 95 association within the Large Magellanic Cloud. Using noncontemporaneous wideband optical and narrowband H{alpha} photometry obtained with the Hubble Space Telescope, we identify 245 low-mass pre-main-sequence (PMS) candidates showing H{alpha} excess emission above the 4{sigma} level. We derive their physical parameters, including effective temperatures, luminosities, masses (M_*_), ages, accretion luminosities, and mass accretion rates (dM/dt_acc_). We identify two different stellar populations: younger than ~8Myr with median dM/dt_acc_~5.4x10^-8^M_{sun}_/yr (and M_*_~0.15-1.8M_{sun}_) and older than ~8Myr with median dM/dt_acc_~4.8x10^-9^M_{sun}_/yr (and M_*_~0.6-1.2M_{sun}_). We find that the younger PMS candidates are assembled in groups around Be stars, while older PMS candidates are uniformly distributed within the region without evidence of clustering. We find that dM/dt_acc_ in LH 95 decreases with time more slowly than what is observed in Galactic star-forming regions (SFRs). This agrees with the recent interpretation, according to which higher metallicity limits the accretion process in both rate and duration due to higher radiation pressure. The dM/dt_acc_-M_*_ relationship shows different behavior at different ages, becoming progressively steeper at older ages, indicating that the effects of mass and age on dM/dt_acc_ cannot be treated independently. With the aim to identify reliable correlations between mass, age, and dM/dt_acc_, we used a multivariate linear regression fit between these parameters for our PMS candidates. The comparison between our results and those obtained in other SFRs of our Galaxy and the Magellanic Clouds confirms the importance of the metallicity for the study of the dM/dt_acc_ evolution in clusters with different environmental conditions.2019ApJ...875...51Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/875/51CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)J/ApJ/661/1119 : Spectroscopy in the 25 Ori group (Briceno+, 2007)J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)J/ApJ/710/597 : Accretion in disks in Cep OB2 (Sicilia-Aguilar+, 2010)J/MNRAS/415/103 : IPHAS T Tauri candidates in IC 1396 (Barentsen+, 2011)J/A+A/525/A47 : U-band photometry in sigma Orionis region (Rigliaco+, 2011)J/A+A/533/A109 : Pisa pre-main sequence tracks & isochrones (Tognelli+, 2011)J/ApJ/746/29 : High-resolution GC abundances. IV. 8 LMC GCs (Colucci+, 2012)J/MNRAS/421/78 : LMC PMS stars mass accretion rates (Spezzi+, 2012)J/MNRAS/429/1981 : NGC 2264 T Tauri star properties (Barentsen+, 2013)J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)J/AJ/146/85 : Spectral types of 1576 opt. stars in ONC (Hillenbrand+, 2013)J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/A+A/561/A2 : 36 accreting YSOs emission lines (Alcala+, 2014)J/MNRAS/442/1663 : Velocities of red giants in the SMC (Dobbie+, 2014)J/A+A/580/A26 : T Tauri star population in Lupus (Galli+, 2015)J/A+A/600/A20 : Lupus YSOs X-shooter spectroscopy (Alcala+, 2017)J/ApJ/847/31 : Protoplanetary disk data in Cha I and Lupus (Mulders+, 2017)J/AJ/157/85 : CIDA Variability Survey of Orion OB1. II. (Briceno+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/875/51https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/875/51http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/875/51https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/875/51https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/875/51http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/875/51GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/875/51/table3 (Stellar parameters of our low-mass pre-main-sequence (PMS) accreting candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/51/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/51/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/51/table3?GETtext/xml+votable180.050000true84.31741-66.342440.0055555555555555566/33116https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/875/51?format=asciiOpticalInfrareddefaultJ/ApJ/875/51/table3Stellar parameters of our low-mass pre-main-sequence (PMS) accreting candidatese_F555Wmag[0.01/0.1] Uncertainty in F555Wmagmagstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSet[1/2] Candidate subset population (1)meta.codeintID[100583/206419] Object ID within our catalogmeta.id;meta.mainintRAJ2000[84.19/84.34] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-66.4/-66.3] Declination (J2000)degpos.eq.dec;meta.mainF555Wmag[21.87/26.55] Dereddened HST F555W magnitudemagphot.mag;em.opt.VfloatF814Wmag[20.73/25.4] Dereddened HST F814W magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[0.01/0.07] Uncertainty in F814Wmagmagstat.errorfloatF658Nmag[20.72/25.11] Dereddened HST F658N magnitudemagphot.mag;em.opt.Rfloate_F658Nmag[0.003/0.3] Uncertainty in F658Nmagmagstat.errorfloatEWHa[12.7/66.5] Equivalent width, H{alpha}, in Angstroms0.1nmspect.line.eqWidthfloate_EWHa[0.4/3.3] Uncertainty in EWHa0.1nmstat.errorfloatTeff[3135/7323] Stellar effective temperatureKphys.temperature.effectiveinte_Teff[10/183] Uncertainty in TeffKstat.error;phys.temperature.effectiveintLstar[0.08/5.83] Stellar luminositysolLumphys.luminosityfloate_Lstar[0.01/0.2] Uncertainty in LstarsolLumstat.errorfloatMstar[0.2/1.8] Stellar masssolMassphys.massfloatl_logt[> ] Limit flag on logtmeta.code.errorcharlogt[3.6/7.8] Log of agelog(yr)time.agefloatlogLacc[-1.3/0.5] Log of accretion luminositylog(solLum)phys.luminosityfloatlogMacc[-8.7/-5.7] Log of measured accretion ratelog(solMass.yr**-1)arith.ratefloatSimbadSimbad column added by the CDSmeta.ref.urlchar