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Letter to the Editor
The LMC stellar complexes in luminosity slices
Star formation indicators
F. Maragoudaki 1, 2,
M. Kontizas 1,
E. Kontizas 2,
A. Dapergolas 2 and
D.H. Morgan 3
Received 16 July 1998 / Accepted 4 August 1998
An approach towards the investigation of the star formation mechanisms in galaxies can be achieved through the search of stellar complexes and the determination of their properties. A method has been developed for the detection of stellar complexes and the derivation of their fundamental properties in the LMC.
Photographic plates taken with the 1.2m U.K. Schmidt Telescope have been digitized by the APM and SuperCosmos machines to produce homogeneous data for extended regions. Star counts have been performed for extended areas in selected luminosity slices and colours (U, HeII, R filters). Isodensity contours have been used to identify the various structures with enhanced stellar number density (3 above the mean background density).
About 50 large stellar groupings have been revealed showing: 1) hierarchical structure, where the smallest are found within the large ones. 2) their size distribution has peaks at 25050 pc (aggregates) and 60050 pc (complexes), there are also a few cases with size 120050 pc (supercomplexes). 3) there is evidence that at the fainter magnitudes these structures are aligned to a general trend whereas at the most bright end (B1, O spectral types) they become more clumpy and symmetrical in shape. The relationship between the above complexes' properties and the various scenarios of star formation are discussed.
Key words: galaxies: stellar content Magellanic Clouds star formation
Send offprint requests to: F. Maragoudaki (e-mail: firstname.lastname@example.org)
Online publication: September 8, 1998