THE NOBEYAMA MILLIMETER ARRAY SURVEY OF YOUNG STELLAR OBJECTS ASSOCIATED WITH THE TAURUS MOLECULAR CLOUD

We have carried out an interferometric survey of 3 mm continuum and CS (J = 2-1) line emissions from 13 optically invisible protostar candid ates and six young T Tauri stars associated with the Taurus molecular cloud. The survey was made using the Nobeyama Millimeter Array with a spatial resolution of 2.'' 18-10 ''. The continuum emission was detect ed from two protostar candidates and five T Tauri stars and was well c oincident with optical or infrared objects. It was not spatially resol ved and most probably originated from compact circumstellar disks. The CS emission was detected around 11 protostar candidates and two T Tau ri stars. The detected CS condensations are extended, with a typical s ize and mass of similar to 2000 AU and 0.01 M., respectively. Among th e eleven protostar candidates with detectable CS emission, seven sourc es, i.e., IRAS 04016+2610 (L1489), IRAS 04169+2702, IRAS 04191+1503, I RAS 04239+2436, L1551-IRS 5, IRAS 04325+2402, and IRAS 04365+2535, hav e the CS emission well coincident with infrared sources, while the oth er four show the CS emission separated away from known infrared source s. Most of the CS emission for the former sources may arise from the i nnermost part of their protostellar envelopes, while that for the latt er sources may originate from compact, dense gas in the vicinity of th e infrared sources. The CS gases toward L1489 and IRAS 04365+2535 have disklike structures of similar to 1500 and similar to 500 AU in radiu s, respectively, with velocity gradients along their major axes. The v elocity gradient of the disklike structure around L1489 may be due to rotation, while the origin of velocity gradient around IRAS 04365+2535 is not clear. L1551-IRS 5 shows compact CS emission, possibly arising from a disk, together with weak extended features that may be attribu ted to a denser part of the outflow. The distribution of CS emission a round IRAS 04368+2557 (L1527) is anticorrelated with its molecular out flow, suggesting that the CS gas may be a dense shell swept up by the outflow. The 3 mm continuum detectability toward the protostar candida tes is significantly smaller than what we would expect from the statis tics of T Tauri disks, which we consider may be due to an evolutionary effect; namely, during the transitional phase from embedded protostar s to revealed T Tauri stars, either the disk mass has rapidly increase d, or dust particles in the disks have grown significantly, or both. F or the embedded protostar candidates, the CS intensity is correlated w ith bolometric luminosity. This may mean that the final stellar mass i s correlated with the mass of dense cores.