Disk and envelope structure in class 0 protostars. II. High-resolution millimeter mapping of the Serpens sample

We present high-resolution CARMA 230GHz continuum imaging of nine deeply embedded protostars in the Serpens Molecular Cloud, including six of the nine known Class 0 protostars in Serpens. This work is part of a program to characterize disk and envelope properties for a complete sample of Class 0 protostars in nearby low-mass star-forming regions. Here, we present CARMA maps and visibility amplitudes as a function of uv-distance for the Serpens sample. Observations are made in the B, C, D, and E antenna configurations, with B configuration observations utilizing the CARMA Paired Antenna Calibration System. Combining data from multiple configurations provides excellent uv-coverage (4-500kλ), allowing us to trace spatial scales from 10 ² to 10⁴AU. We find evidence for compact disk components in all of the observed Class 0 protostars, suggesting that disks form at very early times (t < 0.2Myr) in Serpens. We make a first estimate of disk masses using the flux at 50kλ, where the contribution from the envelope should be negligible, assuming an unresolved disk. The resulting disk masses range from 0.04 M_⊙ to 1.7 M_⊙, with a mean of approximately 0.2 M_⊙. Our high-resolution maps are also sensitive to binary or multiple sources with separations ≳ 250AU, but significant evidence of multiplicity on scales <2000AU is seen in only one source.