A mapping study of L1174 with 13CO J=2-1 and 12CO J=3-2: star formation triggered by a Herbig Ae/Be star

We have carried out a comprehensive study of the molecular conditions and star-forming activities in the dark cloud L1174 using multiwavelength data. Mapping observations of L1174 in (CO)-C-13 J = 2 - 1 and (CO)-C-12 J = 3 - 2 were performed using the Kolner Observatorium fur Submillimetre Astronomie (KOSMA) 3-m telescope. Six molecular cores have been resolved, with masses ranging from 5 to 31 M-circle dot and sizes ranging from 0.17 to 0.39 pc. The large area ahead of the Herbig Be star HD 200775 is expanding and core 1 has a collapse signature. The large linewidths of (CO)-C-13 J = 2 - 1 indicate the ubiquity of the turbulent motions in this region. The spectra of (CO)-C-12 J = 3 - 2 prevalently show conspicuously asymmetric double-peaked profiles. In a large area, red-skewed profiles are detected, suggesting a scenario of global expansion. There is a large cavity around the Herbig Be star HD 200775, which is the brightest star in L1174. The gas around the cavity has been severely compressed by the stellar winds from HD 200775. Feedback from HD 200775 might have helped to form the molecular cores around the cavity. In total, 17 potential young stellar objects from the Two-Micron All-Sky Survey (2MASS) have been identified, according to their 2MASS colour indices. The spatial distribution of these 2MASS sources indicates that some of them have a triggered origin. All this suggests that feedback from a Herbig Ae/Be star might also have the potential to trigger star-forming activities.