H II regions and young star clusters in the magellanic clouds

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5588843

Lee, M G

The stellar content in H II regions and young star clusters of the Magellanic Clouds (MC) was studied by using UBV CCD photometry. The purposes of this study are threefold: to investigate the evolution of massive stars in the H II regions and young star cluster; to derive stellar luminosity functions and to determine the stellar initial mass functions; and to study the structural properties of young star clusters in the Magellanic Clouds. A summary of results are (1) The reddening was determined from the color-color diagram, showing E(B-V) = 0.03-.04 for the LMC and 0.03-.22 for the SMC. The distances derived are (m - M){sub 0} = 18.4 + or - 0.2 for NGC 2004 and (m - M){sub 0} = 18.8 + or - 0.3 for NGC 371. Finally, ages of star clusters in H II regions range from 0 to 8 Myr, and ages of the young clusters studied vary from 8 to 80 Myr. Most of the clusters show an age spread up to 50 Myr, sometimes indicating multiple star formation (NGC 1850, NGC 2004, NGC 2100). (2) The initial mass function of stars in H II regions and young star clusters were determined from the main sequence luminosity functions in U, B, and V. The results show that the IMFs of stars in MC H II regions and young clusters are similar in slope to those for various objects in the Galaxy and the Magellanic Clouds. This leads to the conclusion that the slope of the stellar IMFs for m is greater than or equal to 3 solar mass does not depend on the metallicities, on the masses, nor on the morphological types of galaxies. (3) UBV CCD surface photometry of 7 LMC clusters and 2 SMC clusters is presented. The radial surface brightness profiles of most of these clusters are well fitted by the single-mass isotropic King models. The surface photometry, supplemented by star counts from the literature, was used to determine the structural parameters of the clusters.

• Research Organization: Washington Univ., Seattle, WA (United States)
• OSTI ID: 5588843
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BRIGHTNESS
COSMIC RADIO SOURCES
DATA
EXPERIMENTAL DATA
GALAXIES
H2 REGIONS
INFORMATION
INFRARED SPECTRA
ISOTROPY
MAGELLANIC CLOUDS
MAIN SEQUENCE STARS
MORPHOLOGY
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPECTRA
STAR CLUSTERS
STAR EVOLUTION
STARS