The distribution of carbon and M-type giants in the Magellanic Clouds

Abstract

A near-infrared survey with low dispersion of 37 SMC and 52 LMC sample regions allows one to study the surface distribution of carbon and M-type giants in the Magellanic Clouds. The surveys achieved a high degree of completeness throughout the depths of the Clouds for the carbon stars and for the giants of type M5 or later, and a moderate degree of completeness for those of types M2-M4. The total number of LMC carbon stars in the area covered by the sample regions is about 9500. For the SMC, the number is 2650. The contributions of various stellar components to the surface brightness are discussed. The presence in both Clouds of RR Lyrae stars which represent a stellar population 10 - 15 Gyr old, of carbon stars which represent a population 3 - 5 Gyr old, and of relatively young blue stars may be due to a series of discrete star formation bursts rather than to a continuous process of star births.