Astron. Astrophys. 347, 500-507 (1999)

ISO SWS/LWS observations of SN 1987A ^*

P. Lundqvist ¹, J. Sollerman ¹, C. Kozma ¹, B. Larsson ¹, J. Spyromilio ², A.P.S. Crotts ³, J. Danziger ⁴ and D. Kunze <sup>5

1</sup> Stockholm Observatory, S-133 36 Saltsjöbaden, Sweden
² European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany
³ Columbia University, Department of Astronomy, 538 W. 120th Street, New York, USA
⁴ Osservatorio Astronomico, Via G.B. Tiepolo 11, I-34131 Trieste, Italy
⁵ Max-Planck-Institut für Extraterrestrische Physik, Postfach 1603, D-85740 Garching, Germany

Received 3 February 1999 / Accepted 14 April 1999

Abstract

We report on observations of SN 1987A with ISO SWS/LWS made years after the explosion. No emission from the supernova was seen. In particular, the upper limits on the fluxes of [Fe I] 24.05 and [Fe II] 25.99 on day 3 999 are  Jy and  Jy, respectively. Assuming a homogeneous distribution of ⁴⁴Ti inside , we have made theoretical models to estimate the mass of ejected ⁴⁴Ti. Assessing various uncertainties of the model, we obtain an upper limit of . The implications of this are discussed.

The LWS data display continuum emission as well as nebular lines of [O I], [C II] and [O III] from neighboring photoexcited regions in the LMC. The [O III] lines indicate an electron density of  cm^-3, and the continuum can be explained by dust with a temperature of K. A second dust component with K may also be present.

Key words: stars: supernovae: individual: SN 1987A nuclear reactions, nucleosynthesis, abundances stars: supernovae: general

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

Correspondence to: peter@astro.su.se

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and results
  • 2.1. SWS observations
  • 2.2. LWS observations
• 3. Interpreting the SWS observations
  • 3.1. The model for line emission from the supernova
  • 3.2. Model calculations
  • 3.3. Mass of ⁴⁴Ti from [Fe II] 25.99
• 4. Discussion
  • 4.1. Uncertainties in the modeling
  • 4.2. Implications of the derived mass of ⁴⁴Ti
  • 4.3. Interpretation of LWS observations
• 5. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: June 30, 1999
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