@proceedings{13049,
  author = {Yueming Xu},
  editor = {Richard McCray},
  title = {Late Time Spectrum of SN 1987A},
  abstract = {<p>At late times (200 days), when the photosphere of continuum emission has disappeared from the envelope, the radiation of the supernova 1987A is powered by $\gamma$-rays resulting from 56Co decays. The spectrum formation at such a late time is a highly non-linear process (XU [1]). The $\gamma$-ray photons first lose their energy due to Compton scattering and photoelectric absorption, generating non-thermal energetic electrons. These energetic electrons are then slowed down by Coulomb scattering or ionizing and exciting different ions in the envelope. The ions will recombine and de-excite, radiating away their energy in infrared (IR), optical and primarily ultraviolet (UV) wavebands.</p>
},
  year = {1991},
  pages = {444-453},
  publisher = {Springer New York},
  address = {New York, NY},
  isbn = {978-1-4612-2988-9},
  doi = {10.1007/978-1-4612-2988-9_65},
}