A Physical Basis for the H -band Blue-edge Velocity and Light-curve Shape Correlation in Context of Type Ia Supernova Explosion Physics
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© 2019. The American Astronomical Society. All rights reserved. Our recent work demonstrates a correlation between the high-velocity blue edge, v edge, of the iron-peak Fe/Co/Ni H-band emission feature and the optical light-curve (LC) shape of normal, transitional and subluminous SNe Ia. We explain this correlation in terms of SN Ia physics. v edge corresponds to the sharp transition between the complete and incomplete silicon burning regions in the ejecta. It measures the point in velocity space where the outer 56Ni mass fraction, X Ni, falls to the order of 0.03-0.10. For a given 56Ni mass, M(56Ni), v edge is sensitive to the specific kinetic energy E kin(M(56Ni)/M WD) of the corresponding region. Combining v edge with LC parameters (i.e., s BV, in B and V) allows us to distinguish between explosion scenarios. The correlation between v edge and light-curve shape is consistent with explosion models near the Chandrasekhar limit. However, the available sub-M Ch WD explosion model based on SN 1999by exhibits velocities that are too large to explain the observations. Finally, the subluminous SN 2015bo exhibits signatures of a dynamical merger of two WDs demonstrating diversity among explosion scenarios at the faint end of the SNe Ia population.
author list (cited authors)
Ashall, C., Hoeflich, P., Hsiao, E. Y., Phillips, M. M., Stritzinger, M., Baron, E., ... Taddia, F.
complete list of authors
Ashall, C||Hoeflich, P||Hsiao, EY||Phillips, MM||Stritzinger, M||Baron, E||Piro, AL||Burns, C||Contreras, C||Davis, S||Galbany, L||Holmbo, S||Kirshner, RP||Krisciunas, K||Marion, GH||Morrell, N||Sand, DJ||Shahbandeh, M||Suntzeff, NB||Taddia, F