Millimeter Imaging of the HH 270 Protostellar Core and Outflow

Abstract

The HH 270 region was observed in the C18O and the 13 CO J = 1 → 0 lines with angular resolutions ranging from 3'' to 10''. The dense molecular core containing the centimeter continuum source VLA 1 has a mass of ~1.6 M☉. As the 13CO image shows that the dense core is elongated in the direction perpendicular to the outflow axis, the core may be flattened and viewed nearly edge-on. The 13CO spectrum shows a blue-skewed line profile when the imaging is done at a high resolution, suggesting that the infall motion becomes kinematically important on a small scale, within ~2000 AU from the center. The molecular outflow does not show a large line width, and the outflow axis may be close to the plane of the sky. Archival near-IR images reveal that there is a nebulosity associated with VLA 1, and that VLA 1 and HH 270 IRS are separate objects. Comparison of the near-IR and optical images with an accurate positional alignment shows that VLA 1 is the driving source of the HH 270 flow. If HH 270 IRS is not a background star, the HH 270 core may contain a binary system with inhomogeneous spectral classes: VLA 1 may be a Class 0 protostar, and HH 270 IRS may be a young stellar object with a hotter spectral energy distribution.