Obscured AGB stars in the Magellanic Clouds^*

I. IRAS candidates

¹ Institut d'Astrophysique de Paris, CNRS, 98 bis Bd. Arago, F–75014 Paris, France
² European Southern Observatory, Casilla 19001, Santiago 19, Chile
³ European Southern Observatory, Karl–Schwarzschild Strasse 2, D–85748 Garching bei München, Germany
⁴ Astronomical Institute Anton Pannekoek, University of Amsterdam, Kruislaan 403, NL–1098 SJ Amsterdam, The Netherlands
⁵ Max–Planck–Institut für Astrophysik, Karl–Schwarzschild 1, D–85740 Garching, Germany

Send offprint request to: loup at iap.fr

Received: 30 March 1996
Accepted: 22 January 1997

Abstract

We have selected 198 IRAS sources in the Large Magellanic Cloud, and 11 in the Small Magellanic Cloud, which are the best candidates to be mass–loosing AGB stars (or possibly post–AGB stars). We used the catalogues of Schwering & Israel (1990) and Reid et al. (1990). They are based on the IRAS pointed observations and have lower detection limits than the Point Source Catalogue. We also made cross–identifications between IRAS sources and optical catalogues. Our resulting catalogue is divided in 7 tables. Table 1 lists optically known red supergiants and AGB stars for which we found an IRAS counterpart (7 and 52 stars in the SMC and LMC, respectively). Table 2 lists "obscured” (or "cocoon”) AGB stars or late–type supergiants which have been identified as such in previous works through their IRAS counterpart and JHKLM photometry (2 SMC and 34 LMC sources; no optical counterparts). Table 3 lists known planetary nebulae with an IRAS counterpart (4 SMC and 19 LMC PNe). Table 4 lists unidentified IRAS sources that we believe to be good AGB or post–AGB or PNe candidates (11 SMC and 198 LMC sources). Table 5 lists unidentified IRAS sources which could be any type of object (23 SMC and 121 LMC sources). Table 6 lists IRAS sources associated with foreground stars (29 SMC and 135 LMC stars). Table 7 lists ruled out IRAS sources associated with HII regions, hot stars, etc We show that the sample of IRAS AGB stars in the Magellanic Clouds is very incomplete. Only AGB stars more luminous than typically and with a mass-loss rate larger than typically /yr could be detected by the IRAS satellite. As a consequence, one expects to find very few carbon stars in the IRAS sample. We also expect that most AGB stars with intermediate mass–loss rates have not been discovered yet, neither in optical surveys, nor in the IRAS survey.