A C(18)O (J = 1 goes to 0) survey of protostellar candidates embedded in the Taurus molecular cloud

Abstract

view Abstract Citations (15) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A C 18O (J = 1--0) Survey of Protostellar Candidates Embedded in the Taurus Molecular Cloud Hayashi, Masahiko ; Hasegawa, Tetsuo ; Ohashi, Nagayoshi ; Sunada, Kazuyoshi Abstract C(18)O (J = 1 goes to 0) observations were made toward a sample of 32 protostellar sources associated with the Taurus molecular cloud complex. The sources were selected from the IRAS Point Source Catalog with criteria to pick up solar-type protostar candidates. The C(18)O intensity for the optically invisible objects is correlated with the IRAS flux at 25, 60, and 100 micrometers, while at 12 micrometers the correlation is rather ambiguous. The correlation between the C(18)O intensity and the IRAS flux for the invisible objects suggests that both the C(18)O intensity and the IRAS flux at 25, 60, and 100 micrometers well represent the amount of gas and dust, respectively, in the extended envelopes (radius approximately 400-4000 AU) around these objects, while the worse correlation seen at 12 micrometers is consistent with the 12 micrometers emission arising from compact circumstellar disks. The visible objects show wide scatter in the C(18)O intensity with no clear correlation with the IRAS flux at all four wavelength bands, consistent with the IRAS emission originating from circumstellar disks at any infrared wavelengths. The difference in the correlation between the invisible and visible sources means that protostellar envelopes around invisible sources are dissipated away in the course of evolution from invisible sources into visible ones, probably due to accretion onto the central star or due to being blown off by molecular outflows. The observed smooth decrease of the C(18)O intensity from the invisible to visible sources implies the mass dissipation timescale of approximately 105 yr at a rate of greater than or approximately equal to 6 x 10-7 solar masses/yr. Publication: The Astrophysical Journal Pub Date: May 1994 DOI: 10.1086/174057 Bibcode: 1994ApJ...426..234H Keywords: Carbon Monoxide; Infrared Astronomy; Molecular Clouds; Protostars; Radio Astronomy; Stellar Envelopes; Stellar Evolution; Stellar Mass Accretion; Taurus Constellation; Astronomical Catalogs; Infrared Astronomy Satellite; Radio Telescopes; Spectral Energy Distribution; Astronomy; ISM: CLOUDS; ISM: MOLECULES; RADIO LINES: ISM; STARS: CIRCUMSTELLAR MATTER; STARS: PRE--MAIN-SEQUENCE full text sources ADS | data products SIMBAD (34)