Issue |
A&A
Volume 408, Number 1, September II 2003
|
|
---|---|---|
Page(s) | 245 - 256 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361:20030961 | |
Published online | 17 November 2003 |
The stellar content of OMC 2/3*
1
Astronomisches Institut der Ruhr-Universität Bochum, Universitätsstrasse 159/NA 7, 44780 Bochum, Germany
2
SEST, European Southern Observatory, Alonso de Cordova 3107, Santiago, Chile
Corresponding author: M. Nielbock, mnielboc@eso.org
Received:
25
April
2003
Accepted:
17
June
2003
We have revisited the stellar content of OMC 2 and OMC 3
by means of MIR imaging and NIR photometry; in addition, we have
extended the existing (sub)mm maps by a huge m map obtained with
SIMBA showing new sources and filamentary features for the first
time at that wavelength. The MIR data reveal 43 new sources at N and Q which are partly associated with dense condensations at millimetre
wavelengths. Six close binary sources could be resolved at locations
where existing (sub)mm maps only show single emission peaks; three of
them are classified as early (B-type) systems, one of them is
compatible with type K while the remaining two seem to be T Tauri stars.
Furthermore, the MIR images indicate the existence of separate circumstellar
discs in the K-binary system. NIR colour–colour and colour–magnitude
diagrams obtained from 2MASS data are examined to explore the physical
properties of the sources and to derive the distribution of J
luminosities. There is a clear decrease in luminosity and thus in
stellar mass when going from South to North. Likewise, there is an
anti-correlation between Class I and II objects in both regions:
while OMC 2 contains twice as much Class II objects compared to
Class I, the situation is reversed in OMC 3.
Key words: ISM: dust / stars: circumstellar matter, formation
© ESO, 2003
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