Abstract: Dense gas clouds containing OH, CO, NH3 and H2CO are found in the inner part of the Hi nuclear disk. The molecular spectral lines allow direct observations of the kinematics of the gas near the galactic centre. Strong absorption of the thermal continuum sources by OH and H2CO shows that much of the gas on the near side of the centre can be located in a massive ‘ring’ expanding at 130 km s -1 which may have originated close to the nucleus about 106 yr ago. Observations of CO emission from beyond the centre show that the far side of the ‘ri...
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Topics: 
Astrophysics
Astronomy