Class I Methanol Emission Around DR 21 (OH)

Results of new observations of the vicinity of DR 21 (OH) conducted on the 20-m Onsala radio telescope are presented. The goal was to search for associations between molecular hydrogen emission tracing shock waves and class I methanol maser emission. Observations at 44 and 36 GHz have shown that an extensive region of faint methanol maser emission elongated North-South is probably present in the vicinity of DR 21(OH). The linear size of this structure may be a factor of ten larger than the central region in DR 21(OH) that emits at 44 GHz. Three maser emission peaks are clearly visible in the northern (DR 21N), central (DR 21(OH)), and southern (vicinity of DR 21 West) parts of this structure. Many other structures are also embedded in this region, including the protostellar disk ERO 3 previously detected at 6.7 GHz. Maser components of these objects are formed with velocities from -5 to-2 km/s, with a velocity gradient from -5 in the North to -2 km/s in the South. The spatial resolution of the map is not high enough to distinguish fine structures at 44 GHz associated with spots and jets emitting in molecular hydrogen.