AN UNBIASED SPECTRAL LINE SURVEY TOWARD R CrA IRS7B IN THE 345 GHz WINDOW WITH ASTE

摘要: We have conducted a spectral line survey in the 332 - 364 GHz region with ASTE 10 m telescope toward R CrA IRS7B, low-mass protostar Class 0 or 0/I transitional stage. also performed some supplementary observations 450 band. In total, 16 molecular species are identified region. Strong emission lines of CN and CCH observed, whereas complex organic molecules long carbon-chain which characteristics hot corino warm chemistry (WCCC) source, respectively, not detected. The rotation temperature CH3OH is evaluated to be 31 K, significantly lower than that reported for prototypical IRAS 16293-2422 (~85 K). deuterium fractionation ratios H2CO obtained 0.038 0.050, much those corino. These results suggest weak activity IRS7B. On other hand, related molecules, c-C3H2, found abundant. However, this source cannot classified as WCCC since If represent two extremes chemical compositions sources, IRS7B would mixture these characteristics. UV radiation from nearby Herbig Ae star may affect composition. present demonstrates further diversity star-forming regions.