| Description |
Stars form from contracting molecular cloud cores, but this process relies
heavily on the ability of the core to cool and to overcome the magnetic
barrier; this, in turn, depends on the chemical composition and could
therefore lead to drastically different outcomes at low metallicity. However,
most of what we know about star formation is derived from studies of
solar-metallicity YSOs in the Milky Way. To investigate the role of
metallicity on the star-formation process we propose to observe a sample of
early-stage massive young stellar objects in the metal-poor Small and Large
Magellanic Clouds. These were selected from among sources with spectroscopic
evidence of ice and/or maser emission, and comprise a range in luminosity. We
propose to use PACS and SPIRE FTS to measure the strengths of key atomic and
molecular lines, in order to measure the temperature, density, ionization
state and abundances of the main cooling species in these objects. By
comparing the SMC and LMC samples, and Galactic samples of YSOs, we will
assess the effect of the reduced metallicity on the formation process of
massive stars. |
