Lynds 1527: An Embedded Protobinary System in Taurus

Submillimeter continuum maps at 800 μm of the embedded source IRAS 04368+2557 in L1527 in Taurus show that there are two sources separated by 20'', or 2800 AU. The secondary source is between 2 and 3 times less luminous than the primary source if both sources have similar spectral energy distributions. Large-scale C 18 O J = 1 → 0 emission shows the sources to be embedded in a single dense core, and observations of C 18 O and C 17 O show the sources to be associated with a compact region of high-density gas. Three transitions of C 18 O show a velocity gradient between the two sources. On the smallest size scale, the C 18 O J = 3 → 2 emission has a velocity gradient of 3-7 km s -1 pc -1 . The proximity of the sources in both space and velocity suggest that they are a very young protobinary system. The estimated age of the primary source, 5 × 10 3 yr, is much less than the estimated orbital period, 1.4 × 10 5 yr. The separation and young age of the system indicates that it formed through fragmentation of the dense core during collapse.