The Line-of-Sight Depth of Populous Clusters in the Small Magellanic Cloud

We present an analysis of age, metal abundance, and positional data onpopulous clusters in the Small Magellanic Cloud (SMC) with the ultimate aim ofdetermining the line-of-sight (LOS) depth of the SMC using these clusters asproxies. Our dataset contains 12 objects and is limited to clusters with thehighest quality data for which the ages and abundances are best known and canbe placed on an internally consistent scale. We have analyzed the variation ofthe clusters' properties with position on the sky and with line-of-sight depth.Based on this analysis, we draw the following conclusions. 1) The observationaldata indicates that the eastern side of the SMC (facing the LMC) containsyounger and more metal-rich clusters as compared with the western side. This isnot a strong correlation because our dataset of clusters is necessarilylimited, but it is suggestive and warrants further study. 2) Depending on howthe reddening is computed to our clusters, we find a mean distance modulus thatranges from (m-M)_0 = 18.71 +/- 0.06 to (m-M)_0 = 18.82 +/- 0.05. 3) Theintrinsic +/- 1-sigma line-of-sight depth of the SMC populous clusters in ourstudy is between ~6 kpc and ~12 kpc depending primarily on whether we adopt theBurstein & Heiles reddenings or those from Schlegel et al. 4) Viewing the SMCas a triaxial galaxy with the Declination, Right Ascension, and LOS depth asthe three axes, we find axial ratios of approximately 1:2:4. Taken together,these conclusions largely agree with those of previous investigators and serveto underscore the utility of populous star clusters as probes of the structureof the Small Magellanic Cloud.Comment: 31 pages, 11 figures, accepted for publication in the Astronomical Journa