Hydrogen Content of Young Stellar Clusters. II. Clusters NGC2175, 2264, 2353, and 2362

Abstract

Measurements of the total amount of gaseous hydrogen associated with the O-type stellar clusters NGC 2175, 2264, 2353, and 2362 are reported. For the nebula in which NGC2175 is embedded, a mean electron density of 20cm- 3 and a mass of ionized hydrogen of 1400Mo were obtained. For the nebula in which NGC2264 is embedded, a mean electron density of 10 cm - 3 and a mass of ionized hydrogen of 60Mo (with a possible, though unlikely, additional 40Mo of neutral hydrogen) were obtained. No hydrogen in association with NGC 2353 or 2362 was detected.