2006MNRAS.372.1509O

We investigate the conditions of star formation in the Large Magellanic Cloud (LMC). We have conducted a survey for water maser emission arising from massive young stellar objects in the 30 Doradus region (N157) and several other Hii regions in the LMC (N105A, N113 and N160A). We have identified a new maser source in 30Dor at the systemic velocity of the LMC. We have obtained 3-4 µm spectra, with the European Southern Observatory (ESO)-Very Large Telescope (VLT), of two candidate young stellar objects. N105AIRS1 shows H recombination line emission, and its Spectral Energy Distribution (SED) and mid-infrared colours are consistent with a massive young star ionizing the molecular cloud. N157BIRS1 is identified as an embedded young object, based on its SED and a tentative detection of water ice. The data on these four Hii regions are combined with mid-infrared archival images from the Spitzer Space Telescope to study the location and nature of the embedded massive young stellar objects and signatures of stellar feedback. Our analysis of 30Dor, N113 and N160A confirms the picture that the feedback from the massive O- and B-type stars, which creates the Hii regions, also triggers further star formation on the interfaces of the ionized gas and the surrounding molecular cloud. Although in the dense cloud N105A star formation seems to occur without evidence of massive star feedback, the general conditions in the LMC seem favourable for sequential star formation as a result of feedback. In an Appendix, we present water maser observations of the galactic red giants RDoradus and WHydrae.