The 44Ti-powered spectrum of SN 1987A

By A. Jerkstrand, C. Fransson, C. Kozma. 2011

134 citations recorded by the source corpus.

SN 1987A provides a unique opportunity to study the evolution of a supernova from explosion into very late phases. Owing to the rich chemical structure, the multitude of physical processes involved and extensive radiative transfer effects, detailed modeling is needed to interpret the emission from this and other supernovae. In this paper, we analyze the late-time (about eight years) Hubble Space Telescope spectrum of the SN 1987A ejecta, where 44 Ti is the dominant power source. Based on an explosion model for a 19 Mprogenitor, we compute a model spectrum by calculating the degradation of positrons and gamma-rays from the radioactive decays, solving theequations governing temperature, ionization balance and NLTElevel populations, and treating theradiative transfer with a Monte Carlo technique. We obtain a UV/optical/NIR model spectrum that reproduces most of the lines in the observed spectrum with good accuracy. We find non-local radiative transfer in atomic lines to be an important process also at this late stage of the supernova, with ∼30% of the emerging flux in the optical and NIR coming from scattering/fluorescence. We investigate the question of where the positrons deposit their energy, and favor the scenario where they are locally trapped in the Fe/He clumps by a magnetic field. Energy deposition into these largely neutral Fe/He clumps makes Fe I lines prominent in the emerging spectrum. With the best available estimates for the dust extinction, we determine the amount of 44 Ti produced in the explosion to be 1.5 +0.5 −0.5 × 10 −4 M� .

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/32f15667e28618d75ab9af55f1540b92c27c051f

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA (2013, background): “…supernovae like SN 1987A are highly inhomogeneous, with instabilities and radioactive energy deposition mixing the initially chemically stratiﬁed stellar interior into clumps with different compositions, macroscopically mixed throughout the ejecta volume (McCray 1993; Jerkstrand et al. 2011).”
Observational Constraints on the Progenitors of Core-Collapse Supernovae: The Case for Missing High-Mass Stars (2015, background): “The physical sophistication of the Jerkstrand et al. (2011) code now allows this to be done to high accuracy.”