Astron. Astrophys. 335, L13-L16 (1998)

Letter to the Editor

Compact HII regions in the Large Magellanic Cloud observed by ISO ^*

F. Comerón ¹ and P. Claes <sup>2

1</sup> European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany (e-mail: fcomeron@eso.org)
² ESTEC, European Space Agency, 2200 AG Noordwijk, The Netherlands (e-mail: pclaes@astro.estec.esa.nl)

Received 6 May 1998 / Accepted 18 May 1998

Abstract

We present ISOCAM observations of five fields in the Large Magellanic Cloud centered on IRAS point sources with colors of ultracompact HII regions. Three bright sources of parsec or subparsec size, with luminosities consistent with being embedded O stars, are detected at 15 µm in two fields belonging to the HII region N 159. Using published high resolution radio observations, it is found that two of these sources may be ultracompact HII regions with a turnover frequency above 2.4 GHz, while the other is identified with a known compact HII region. If their nature as true ultracompact HII regions is confirmed by follow-up observations, these objects can provide a first sample useful for future studies of early massive star evolution in a low metallicity environment.

Key words: stars: early-type stars: formation H ii regions Magellanic Clouds

* Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) with the participation of ISAS and NASA.

Send offprint requests to: F. Comerón

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
• 3. Results and discussion
  • 3.1. Fields without bright sources
  • 3.2. The point sources
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: June 12, 1998

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