Grefenstette, B. W., Fryer, C. L., Harrison, F. A., Boggs, S. E., DeLaney, T., Laming, J. M., …Zoglauer, A. (2017). The distribution of radioactive 44Ti in Cassiopeia A. Astrophysical Journal, 834(1), Article 19. https://doi.org/10.3847/1538-4357/834/1/19