Interferometric Observations of Outflows From Low-Mass Protostars in Taurus

Abstract

view Abstract Citations (41) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Interferometric Observations of Outflows From Low-Mass Protostars in Taurus Tamura, Motohide ; Ohashi, Nagayoshi ; Hirano, Naomi ; Itoh, Yoichi ; Moriarty-Schieven, Gerald H. Abstract We have mapped CO J=1-0 outflows from two low-mass protostar candidates in Taurus, IRAS 04365+2535 (TMC1-A) and IRAS 04368+2557 (Li 527), using the Nobeyama Millimeter Array. The outflow structure is compared with deep near-infrared images obtained by IR array detectors. The molecular outflow from IRAS 04365+2535 (TMC1-A) shows a clear bipolar structure whose blueshifted lobe extends to the north-west and redshifted one to the south-east. The extension of the blue shifted lobe is consistent with that of the cometary infrared reflection nebula, suggesting the presence of a large (∼2500 AU) tilted dust disk or elongated envelope which obscures the other side of the nebula, i.e., the redshifted lobe. The outflow associated with IRAS 04368+2557 (L1527) appears to be almost perfectly in the plane of the sky with blueshifted and redshifted lobes significantly overlapped with each other. Both lobes show clear bow-tie shaped, shell-like structure whose geometrical center is coincident with a millimeter continuum point-like source. Deep near-infrared images have revealed that a faint bipolar infrared nebulosity is associated with the "edge-on" molecular outflow. The central source, totally invisible even at near-infrared wavelengths, might be heavily obscured by a disk or an elongated envelope whose size is comparable to the IR nebula (∼10 000 AU). These two IRAS sources show large difference in their near-infrared appearance even though they have similar physical properties including bolometric luminosity, association of CO outflows, and submillimeter/millimeter flux. This difference might be due to the inclination effect: the central part of IRAS 04368+2557 is more heavily obscured (Aυ∼70 mag) along the line of sight than that of IRAS 04365+2535 by the envelope of a disk-like structure with almost edge-on geometry. The difference of the appearance of CO outflow between these two sources is consistent with this interpretation. Although IRAS 04368+2557 is regarded as a Class 0 source, our observations suggest that this source could be similar to IRAS 04365+2535, a Class 1 source, in nature, except for the geometry of the circumstellar envelope. Publication: The Astronomical Journal Pub Date: November 1996 DOI: 10.1086/118164 Bibcode: 1996AJ....112.2076T Keywords: STARS: LOW-MASS; INFRARED: STARS; STARS: PRE-MAIN SEQUENCE full text sources ADS | data products SIMBAD (30)