The low-mass stellar population in the young cluster Tr37: Disk evolution, accretion, and environment

摘要: We present a study of accretion and protoplanetary disks around M-type stars in the 4 Myr-old cluster Tr37. With well-studied solar-type population, Tr37 is benchmark for disk evolution. used low-resolution spectroscopy to identify 141 members (78 new) 64 probable members, mostly stars. H\alpha\ emission provides information about accretion. Optical, 2MASS, Spitzer, WISE data are trace SEDs. construct radiative transfer models explore structures full-disks, pre-transition, transition, dust-depleted disks. Including new previously known we confirm that substantial fraction (~2/5) show signs evolution, either as radial dust evolution (transition/pre-transition disks) or more global (low small-dust masses, settling, weak/absent signatures). Accretion strongly dependent on SED type. About half transition objects consistent with no accretion, have weak (or undetectable) signatures, especially among The analysis structure suggests parallel gas. find several distinct classes evolved disks, based type pointing different dispersal mechanisms probably evolutionary paths. Dust depletion opening inner holes appear be independent processes: most not dust-depleted, do require holes. differences between (4 Myr) remarkable young, sparse, Coronet (1-2 Myr), suggesting other factors, like environment/interactions, likely play role dispersal. Finally, also some evidence clumpy star formation mini-clusters within