The Late Behavior of Supernova 1987A. I. The Light Curve
Abstract
Theoretical models are compared to observations of the late (τ = 20-1500 days) bolometric light curve and the γ-lines and X-rays from supernova 1987A. The analytic methods of Arnett (1982) are generalized to include recombination effects on opacity and energetics and are compared to numerical results. Enforcing constraints obtained from numerical work (Arnett 1987, 1988b) on the early observational data (τ < 20 days), the effects of radioactive heating, gamma escape, and pulsar heating are examined. The presence of 0.073 +/- 0.015 M_sun_ of freshly synthesized ^56^Ni is needed to fit the bolometric light curve; the error estimate is dominated by uncertainty in the distance to the supernova. This matter must be well distributed in attenuation depth in the ejecta, as could be the case if the Rayleigh-Taylor instability encountered by Arnett (1987, 1988a) were operative, and/or clumping in density occurred. This modifies the light curve and predictions of X-ray and γ-ray escape. The γ-ray line flux is sensitive to the density and position of the radio-active matter; this may provide a constraint on the nature of the explosion. The accurately exponential decay of the bolometric light curve for τ > 120 days places severe limits on the luminosity (L <= 2 x 10^39^ ergs s^-1^) and the presumed period (P >= 2 x 10^-2^ s) of the newly formed pulsar/neutron star. Some possible observational signatures of such an object are presented.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1989
- DOI:
- 10.1086/167402
- Bibcode:
- 1989ApJ...340..396A
- Keywords:
-
- Gamma Ray Astronomy;
- Light Curve;
- Supernova 1987a;
- X Ray Sources;
- Neutron Stars;
- Nuclear Fusion;
- Pulsars;
- Radiative Transfer;
- Stellar Mass Ejection;
- Astrophysics;
- GAMMA RAYS: GENERAL;
- NUCLEOSYNTHESIS;
- STARS: INDIVIDUAL ALPHANUMERIC: SN 1987A;
- STARS: SUPERNOVAE;
- X-RAYS: SOURCES