2004/01/15 by David Branch, D. Branch, R. C. Thomas +12 · 36 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Gamma-ray bursts and supernovae #Light curve #Line (geometry) #Photosphere #Spectral line #Supernova #Type (biology) #astro-ph
paper · pdf · doi:10.1086/382950
published in The Astrophysical Journal 606(1), 413-423 (IOP Publishing) · 41 pages including 21 figures, accepted by ApJ
arxiv created 2004/01/15 · openalex publication_date 2004/04/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Type Ia supernova (SN) 2000cx exhibited multiple peculiarities, including a lopsided B -band light-curve peak that does not conform to current methods for using shapes of light curves to standardize SN Ia luminosities. We use the parameterized SN synthetic-spectrum code SYNOW to study line identifications in the photospheric-phase spectra of SN 2000cx. Previous work established the presence of Ca II infrared triplet features forming above velocity ~20,000 km s -1 , much higher than the photospheric velocity of ~10,000 km s -1 . We find Ti II features forming at the same high velocity. High-velocity line formation is partly responsible for the photometric peculiarities of SN 2000cx: for example, B -band flux blocking by Ti II absorption features that decreases with time causes the B light curve to rise more rapidly and decline more slowly than it otherwise would. SN 2000cx contains an absorption feature near 4530 Å that may be Hβ, forming at the same high velocity. The lack of conspicuous Hα and Paα signatures does not necessarily invalidate the Hβ identification if the high-velocity line formation is confined to a clump that partly covers the photosphere and the Hα and Paα source functions are elevated relative to that of resonance scattering. The Hβ identification is tentative. If it is correct, the high-velocity matter must have come from a nondegenerate companion star.