  We present dual-wavelength observations and modeling of the nearly edge-on
Class 0 young stellar object L1157-mm. Using the Combined Array for Research in
Millimeter-wave Astronomy, a nearly spherical structure is seen from the
circumstellar envelope at the size scale of 10^2 to 10^3 AU in both 1 mm and 3
mm dust emission. Radiative transfer modeling is performed to compare data with
theoretical envelope models, including a power-law envelope model and the
Terebey-Shu-Cassen model. Bayesian inference is applied for parameter
estimation and information criteria is used for model selection. The results
prefer the power-law envelope model against the Terebey-Shu-Cassen model. In
particular, for the power-law envelope model, a steep density profile with an
index of ~2 is inferred. Moreover, the dust opacity spectral index (beta) is
estimated to be ~0.9, implying that grain growth has started at L1157-mm. Also,
the unresolved disk component is constrained to be < 40 AU in radius and < 4-25
M_Jup in mass. However, the estimate of the embedded disk component relies on
the assumed envelope model.
