LMC H II Region N11C

An image of the LMC H II region N11C taken with the ESO NTT
and an Strömgren y filter
Based on imaging and spectroscopy obtained at the ESO NTT telescope and using an efficient image analysis algorithm, we study the core of the LMC OB association LH13, particularly the two compact stellar clusters Sk-66°41 and HNT in the Hii region N11C. Attaining a resolution of 0.13 arcsec (FWHM), we resolve Sk-66°41, which has a mere 3 x 3 arcsec size, into 15 components and for the first time the HNT cluster into 70 stars; and moreover derive photometry for the members. Click here to read the decomposition history of Sk-66°41, once believed to be a "supermassive" star with a mass well over 120 Solar masses.

From medium resolution spectroscopy we determine the spectral types for 16 stars in N11C. The main component of the Sk-66°41 cluster is classified O3 V((f*)) + OB, while Wo 599 turns out to be O4 V ((f+)) + O. We compare the color-magnitude diagrams of the clusters with that of the field stars and discuss the cluster ages. With an age of about 100 Myr, the HNT cluster appears significantly older than the very young (< or = 5 Myr) Sk-66°41 starburst.

We suggest that most of the `field' O-stars in the core of LH13 (Wo 597, Wo 599, Wo 622, etc.) have actually been ejected from Sk-66°41 through dynamical interactions in the compact cluster. The properties of the Sk-66°41 and HNT clusters suggest that we are viewing different star formation regions lying at different distances along the same line of sight.

A&A paper (M. Heydari-Malayeri, P. Royer, G. Rauw, N.R. Walborn 2000)

See this note!

Decomposition history of the LMC cluster Sk-66°41

Images of N11C

References on N11C

References on Sk-66°41