The L 1157 protostellar outflow imaged with the Submillimeter Array(Corrigendum)

Abstract

Using the line ratio between the SiO (5–4) and the SiO (2–1) observed by Zhang et al. (2000) with a synthesized beam of 9. ′′5× 8. ′′0, we derived the physical conditions of the gas in the high-velocity clumps. For our analysis we selected the portion of the high-velocity range that is less affected by the missing flux. The analysis was performed at the B0i and B1a positions, at which the SiO (5–4) emission was detected above the 5σ level. We note that an analysis using several SiO lines observed with a single-dish telescope has been made by Nisini et al. (2007). However, they used single-pointing observations, which means that the data were taken with different beam sizes, for instance ∼27′′for SiO (2–1) and ∼11′′for SiO (5–4). In addition, the line ratios used the total integrated intensity, including the low-velocity component, where as we used higher-resolution data and focused on the high-velocity component. Since the interferometric SiO (2–1) observations agreed to better than 20% with the single-dish results, Zhang et al. (2000) concluded that most of the SiO (2–1) flux was recovered with the interferometer. Therefore we did not take into account the effect of the missing flux in this transition. Our SiO (5–4) observations were convolved to the angular resolution of the SiO (2–1) data (i.e. 9. ′′5×8. ′′0). In Fig. 10 we show the SiO (5–4) and (2–1) spectra at the position of clumps B0i and B1a in a brightness-temperature scale. The portion of the high-velocity range in which most of the single-dish SiO (5–4) emission at the B1a position is recovered by our SMA observations is –16.0 to –10.8 km s−1. We assumed the velocity range for the B0i clump to be the same as that of the B1a clump. The linewidth was assumed to be 5 km s−1 for both B1a and B0i. Since smoothing the SMA maps to ∼9′′ beam averaged the emission of adjacent clumps, the spectrum at B1a includes the emission from