Title: Spectral models for early time SN 2011fe observations

Abstract

We use observed UV through near-IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal Type Ia supernovae (SNe Ia) and to examine its individual peculiarities. As a benchmark, we use a delayed-detonationmodel with a progenitormetallicity of Z_⊙/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. The effect of metallicity variations in the progenitor have a relatively small effect on the synthetic spectra. We also find that the abundance stratification of SN 2011fe resembles closely that of a delayed-detonation model with a transition density that has been fit to other Branch-normal SNe Ia. At early times, the model photosphere is formed in material with velocities that are too high, indicating that the photosphere recedes too slowly or that SN 2011fe has a lower specific energy in the outer ≈0.1 M_⊙ than does the model. We discuss several explanations for the discrepancies. Lastly, we examine variations in both the spectral energy distribution and in the colours due to variations in the progenitor metallicity, which suggests that colours are only weak indicators for the progenitor metallicity, in the particular explosion model that we havemore » studied. Here we do find that the flux in the U band is significantly higher at maximum light in the solar metallicity model than in the lower metallicity model and the lower metallicity model much better matches the observed spectrum.« less

Authors:

Baron, E. ^[1]; Hoeflich, P. ^[2]; Friesen, Brian ^[3]; Sullivan, M. ^[4]; Hsiao, E. ^[5]; Ellis, R. S. ^[6]; Gal-Yam, A. ^[7]; Howell, D. A. ^[8]; Nugent, P. E. ^[9]; Dominguez, I. ^[10]; Krisciunas, K. ^[11]; Phillips, M. M. ^[5]; Suntzeff, N. ^[11]; Wang, L. ^[11]; Thomas, R. C. ^[10]

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+ Show Author Affiliations

1. Univ. of Oklahoma, Norman, OK (United States). Homer L. Dodge Dept. of Physics and Astronomy; Hamburger Sternwarte, Hamburg (Germany)
2. Florida State Univ., Tallahassee, FL (United States). Dept. of Physics
3. Univ. of Oklahoma, Norman, OK (United States). Homer L. Dodge Dept. of Physics and Astronomy
4. Univ. of Southampton (United Kingdom). School of Physics and Astronomy
5. Las Campanas Observatory, La Serena (Chile)
6. California Inst. of Technology (CalTech), Pasadena, CA (United States). Cahill Center for Astrophysics
7. Weizmann Inst. of Science, Rehovot (Israel). Benoziyo Center for Astrophysics
8. Las Cumbres Observatory Global Telescope Network, Goleta, CA (United States); Univ. of California, Santa Barbara, CA (United States). Dept. of Physics
9. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Cosmology Center
10. Univ. of Granada (Spain)
11. Texas A & M Univ., College Station, TX (United States). Dept. of Physics and Astronomy, George P. and Cynthia Woods Mitchell Inst. for Fundamental Physics and Astronomy

Publication Date:

Tue Oct 13 00:00:00 EDT 2015

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); German Research Foundation (DFG); Spanish Ministry of Science and Innovation

OSTI Identifier:

1407294

Grant/Contract Number:  

AC02-05CH11231; NAS5-26555; AST-0703902

Resource Type:

Accepted Manuscript

Journal Name:

Monthly Notices of the Royal Astronomical Society

Additional Journal Information:

Journal Volume: 454; Journal Issue: 3; Journal ID: ISSN 0035-8711

Publisher:

Royal Astronomical Society

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; radiative transfer; supernovae general; supernovae individual; SN 2011fe