Galaxies central-dominant

Embsion in the 1-0 S(l) line of H2 was detected in all cooling flow central dominant galaxies with Ha emission. Thus, cold molecular material is found in a large number of the central dominant galaxies within X-ray cooli g flows. 

Dwarf Spheroidal galaxies are the smallest and faintest galaxies known. They are typically dominated by old stellar populations (e.g. Sculptor and Sextans), but some of them (e.g. Fornax) exhibit more recent star formation episodes (2-8 Gyr ago). Analysis of the horizontal branch morphology shows that Red HB stars are more centrally concentrated than Blue HB stars which could be interpreted either as an age or a metallicity gradient or both ([1]). Only spectroscopic observations can unambiguously separate metallicity gradients and make a link with the kinematics. 

M87, the dominant central galaxy in the nearby Virgo cluster is a shows the detailed interaction between the X-ray emitting gas and the central supermassive black hole. The Chandra images also show cavities and filaments in the eastern and southwestern X-ray arms (see Young et al. 2002 and Forman et al. 2004). 

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