TY - JOUR
T1 - Carnegie Supernova Project-II
T2 - Using Near-infrared Spectroscopy to Determine the Location of the Outer 56Ni in Type Ia Supernovae
AU - Ashall, C.
AU - Hsiao, E. Y.
AU - Hoeflich, P.
AU - Stritzinger, M.
AU - Phillips, M. M.
AU - Morrell, N.
AU - Davis, S.
AU - Baron, E.
AU - Piro, A. L.
AU - Burns, C.
AU - Contreras, C.
AU - Galbany, L.
AU - Holmbo, S.
AU - Kirshner, R. P.
AU - Krisciunas, K.
AU - Marion, G. H.
AU - Sand, D. J.
AU - Shahbandeh, M.
AU - Suntzeff, N. B.
AU - Taddia, F.
N1 - Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved.
PY - 2019/4/20
Y1 - 2019/4/20
N2 - We present the H-band wavelength region of 37 postmaximum light near-infrared spectra of three normal, nine transitional, and four subluminous type Ia supernovae (SNe Ia), extending from +5 days to +20 days relative to the epoch of B-band maximum. We introduce a new observable, the blue-edge velocity, v edge, of the prominent Fe/Co/Ni-peak H-band emission feature, which is quantitatively measured. The v edge parameter is found to decrease over subtype ranging from around -14,000 km s-1 for normal SNe Ia, to -10,000 km s-1 for transitional SNe Ia, down to -5000 km s-1 for the subluminous SNe Ia. Furthermore, inspection of the +10 ± 3 days spectra indicates that v edge is correlated with the color-stretch parameter, s BV, and hence with peak luminosity. These results follow the previous findings that brighter SNe Ia tend to have 56Ni located at higher velocities as compared to subluminous objects. As v edge is a model-independent parameter, we propose it can be used in combination with traditional observational diagnostics to provide a new avenue to robustly distinguish between leading SNe Ia explosion models.
AB - We present the H-band wavelength region of 37 postmaximum light near-infrared spectra of three normal, nine transitional, and four subluminous type Ia supernovae (SNe Ia), extending from +5 days to +20 days relative to the epoch of B-band maximum. We introduce a new observable, the blue-edge velocity, v edge, of the prominent Fe/Co/Ni-peak H-band emission feature, which is quantitatively measured. The v edge parameter is found to decrease over subtype ranging from around -14,000 km s-1 for normal SNe Ia, to -10,000 km s-1 for transitional SNe Ia, down to -5000 km s-1 for the subluminous SNe Ia. Furthermore, inspection of the +10 ± 3 days spectra indicates that v edge is correlated with the color-stretch parameter, s BV, and hence with peak luminosity. These results follow the previous findings that brighter SNe Ia tend to have 56Ni located at higher velocities as compared to subluminous objects. As v edge is a model-independent parameter, we propose it can be used in combination with traditional observational diagnostics to provide a new avenue to robustly distinguish between leading SNe Ia explosion models.
KW - supernovae: general
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U2 - 10.3847/2041-8213/ab1654
DO - 10.3847/2041-8213/ab1654
M3 - Article
AN - SCOPUS:85069435168
SN - 2041-8205
VL - 875
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L14
ER -