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We report the results of our observations of the S255IR area with the SMA at1.3 mm in the very extended configuration and at 0.8 mm in the compactconfiguration as well as with the IRAM-30m at 0.8 mm. The best achieved angularresolution is about 0.4 arcsec. The dust continuum emission and several tens ofmolecular spectral lines are observed. The majority of the lines is detectedonly towards the S255IR-SMA1 clump, which represents a rotating structure(probably disk) around the young massive star. The achieved angular resolutionis still insufficient for conclusions about Keplerian or non-Kepleriancharacter of the rotation. The temperature of the molecular gas reaches 130-180K. The size of the clump is about 500 AU. The clump is strongly fragmented asfollows from the low beam filling factor. The mass of the hot gas issignificantly lower than the mass of the central star. A strong DCN emissionnear the center of the hot core most probably indicates a presence of arelatively cold ($\lesssim 80$ K) and rather massive clump there. High velocityemission is observed in the CO line as well as in lines of high density tracersHCN, HCO+, CS and other molecules. The outflow morphology obtained fromcombination of the SMA and IRAM-30m data is significantly different from thatderived from the SMA data alone. The CO emission detected with the SMA tracesonly one boundary of the outflow. The outflow is most probably driven by jetbow shocks created by episodic ejections from the center. We detected a densehigh velocity clump associated apparently with one of the bow shocks. Theoutflow strongly affects the chemical composition of the surrounding medium.

The disk-outflow system in the S255IR area of high mass star formation