The kinematics , structure , and stellar population properties in the centers of two early-type spiral galaxies of the Leo Triplet , NGC 3627 and NGC 3623 , are studied by means of integral-field spectroscopy .
Unlike our previous targets , NGC 3384/NGC 3368 in the Leo I Group and NGC 5574/NGC 5576 in LGG 379 , NGC 3623 and NGC 3627 do not appear to experience a synchronous evolution .
The mean ages of their circumnuclear stellar populations are quite different , and the magnesium overabundance of the nucleus in NGC 3627 is evidence for a very brief last star formation event 1 Gyr ago whereas the evolution of the central part of NGC 3623 looks more quiescent .
In the center of NGC 3627 we observe noticeable gas radial motions , and the stars and the ionized gas in the center of NGC 3623 demonstrate more or less stable rotation .
However , NGC 3623 has a chemically distinct core – a relic of a past star formation burst – which is shaped as a compact , dynamically cold stellar disk with a radius of \sim 250 - 350 pc which has been formed not later than 5 Gyr ago .