2026-05-25T00:45:25Zhttps://keep.lib.asu.edu/oai/request

oai:keep.lib.asu.edu:node-1295182025-05-20T15:17:28Zoai_pmh:alloai_pmh:repo_items

129518 https://hdl.handle.net/2286/R.I.27105 <p>Seitenzahl, Ivo R., Timmes, F. X., &amp; Magkotsios, Georgios (2014). THE LIGHT CURVE OF SN 1987A REVISITED: CONSTRAINING PRODUCTION MASSES OF RADIOACTIVE NUCLIDES. ASTROPHYSICAL JOURNAL, 792(1), 10. http://dx.doi.org/10.1088/0004-637X/792/1/10</p> 10.1088/0004-637X/792/1/10 0004-637X 1538-4357 http://rightsstatements.org/vocab/InC/1.0/ 2014-09-01 2015-08-08T17:22:50 7 pages eng Seitenzahl, Ivo R. Timmes, Francis Magkotsios, Georgios College of Liberal Arts and Sciences Copyright IOP Publishing. This is the authors' final, peer-reviewed manuscript. The final version as published can be viewed online at http://dx.doi.org/10.1088/0004-637X/792/1/10 <p>We revisit the evidence for the contribution of the long-lived radioactive nuclides ⁴⁴Ti, ⁵⁵Fe, ⁵⁶Co, ⁵⁷Co, and ⁶⁰Co to the UVOIR light curve of SN 1987A. We show that the V-band luminosity constitutes a roughly constant fraction of the bolometric luminosity between 900 and 1900 days, and we obtain an approximate bolometric light curve out to 4334 days by scaling the late time V-band data by a constant factor where no bolometric light curve data is available. Considering the five most relevant decay chains starting at ⁴⁴Ti, ⁵⁵Co, ⁵⁶Ni, ⁵⁷Ni, and ⁶⁰Co, we perform a least squares fit to the constructed composite bolometric light curve. For the nickel isotopes, we obtain best fit values of M(⁵⁶Ni) = (7.1 ± 0.3) × 10^-2 M ☉ and M(⁵⁷Ni) = (4.1 ± 1.8) × 10^-3 M ☉. Our best fit ⁴⁴Ti mass is M(⁴⁴Ti) = (0.55 ± 0.17) × 10^-4 M ☉, which is in disagreement with the much higher (3.1 ± 0.8) × 10^-4 M ☉ recently derived from INTEGRAL observations. The associated uncertainties far exceed the best fit values for ⁵⁵Co and ⁶⁰Co and, as a result, we only give upper limits on the production masses of M(⁵⁵Co) &lt; 7.2 × 10^-3 M ☉ and M(⁶⁰Co) &lt; 1.7 × 10^-4 M ☉. Furthermore, we find that the leptonic channels in the decay of [superscript 57]Co (internal conversion and Auger electrons) are a significant contribution and constitute up to 15.5% of the total luminosity. Consideration of the kinetic energy of these electrons is essential in lowering our best fit nickel isotope production ratio to [⁵⁷Ni/⁵⁶Ni] = 2.5 ± 1.1, which is still somewhat high but is in agreement with gamma-ray observations and model predictions.</p> Text The Light Curve of SN 1987A Revisited: Constraining Production Masses of Radioactive Nuclides