J/ApJ/849/149ivo://CDS.VizieR/J/ApJ/849/149doi:10.26093/cds/vizier.18490149CDSSun N.-C.de Grijs R.Subramanian S.Bekki K.Bell C.P.M.,Cioni M.-R.L.Ivanov V.D.Marconi M.Oliveira J.M.Piatti A.E.,Ripepi V.Rubele S.Tatton B.L.van Loon J.T.2018-08-20T08:21:06Z2018-07-19T12:47:55ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsinfrared-sourcessurveysStar formation is a hierarchical process, forming young stellar structures of star clusters, associations, and complexes over a wide range of scales. The star-forming complex in the bar region of the Large Magellanic Cloud is investigated with upper main-sequence stars observed by the VISTA Survey of the Magellanic Clouds. The upper main-sequence stars exhibit highly nonuniform distributions. Young stellar structures inside the complex are identified from the stellar density map as density enhancements of different significance levels. We find that these structures are hierarchically organized such that larger, lower-density structures contain one or several smaller, higher- density ones. They follow power-law size and mass distributions, as well as a lognormal surface density distribution. All these results support a scenario of hierarchical star formation regulated by turbulence. The temporal evolution of young stellar structures is explored by using subsamples of upper main-sequence stars with different magnitude and age ranges. While the youngest subsample, with a median age of log({tau}/yr)=7.2, contains the most substructure, progressively older ones are less and less substructured. The oldest subsample, with a median age of log({tau}/yr)=8.0, is almost indistinguishable from a uniform distribution on spatial scales of 30-300pc, suggesting that the young stellar structures are completely dispersed on a timescale of ~100Myr. These results are consistent with the characteristics of the 30 Doradus complex and the entire Large Magellanic Cloud, suggesting no significant environmental effects. We further point out that the fractal dimension may be method dependent for stellar samples with significant age spreads.2017ApJ...849..149Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/849/149CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/351 : VISTA Magellanic Survey (VMC) catalog (Cioni+, 2011)J/A+AS/104/379 : Integrated Photometry of open clusters (Battinelli+ 1994)J/A+A/397/473 : HST photometry of M51 cluster (Bik+, 2003)J/AJ/127/1531 : Star formation history of SMC (Harris+, 2004)J/AJ/127/1632 : UBVR(UIT) photometry of O and OB stars in SMC (Oey+, 2004)J/AJ/128/1606 : Magellanic Clouds Photometric Survey: LMC (Zaritsky+, 2004)J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)J/ApJS/178/56 : CO observations of LMC Giant Molecular clouds (Fukui+, 2008)J/AJ/138/1243 : The star formation history of the LMC (Harris+, 2009)J/MNRAS/403/996 : Clusters and associations in SMC and LMC (Bonatto+, 2010)J/ApJ/723/492 : Physical data of GRS molecular clouds (Roman-Duval+, 2010)J/ApJ/727/64 : Young stellar groups & their massive stars (Kirk+, 2011)J/A+A/542/A66 : YSOs in 9 LMC star forming regions (Carlson+, 2012)J/MNRAS/452/3508 : Young stellar structures in NGC 6503 (Gouliermis+, 2015)J/MNRAS/454/839 : VMC survey. XVI. (Piatti+, 2015)J/MNRAS/449/639 : VMC survey. XIV. SFR in SMC (Rubele+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/849/149https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/849/149http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/849/149https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/849/149https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/849/149http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/849/149GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/849/149/table1 (Identified young stellar structures)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/849/149/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/849/149/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/849/149/table1?GETtext/xml+votable180.050000true146.1157-67.86030.0055555555555555566/32991 33040 33053 33078 33136 33205 33219 33250 33279 33349 33527 33591 33597 33615 33621 33655 33804 33819 33834 33840 33846 33855 33894 34019 34035 34055 34056 34083 34203 34234 34254 34354 34355 34373 34378 34399 34452 34461 34496 34528 34594 35080 35082 35083 35103 35145 35147 35889 35904 35920 35930 36909 36911 36959 36962 37047 37082 37084 37108 37145 37182 37222 37224 37244 37249 37252 37262 37316 37330 37370 37395 37418 37458 37489 37530 37550 37555 37580 37595 37626 37646 37731 37775 37779 37782 37897 39006 39070 39431 39470 45475https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/849/149?format=asciiInfrareddefaultJ/ApJ/849/149/table1Identified young stellar structuresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/123] Internal index numbermeta.id;meta.mainintsig[1/10] Significance level (see Figure 4)stat.fit.goodnessintRAJ2000[28.8/320.5] Right Ascension (J2000) (1)degpos.eq.ra;meta.mainDEJ2000[-82.5/-30] Declination (J2000) (1)degpos.eq.dec;meta.mainR[2.5/213] Size parameter (2)pcphys.size.radiusfloatN*[4.5/4419.2] Mass; expressed in N_*_ (the number of upper main-sequence stars in a structure)phys.massfloatSDen[0.01/0.5] Surface density (3)pc**-2phot.flux.density.sbfloat