Ultraviolet Line Identifications and Spectral Formation Near Max-Light in Type Ia Supernovae 2011fe

Abstract

We present ultraviolet line identifications of near maximum-light HST observations of SN 2011fe using synthetic spectra generated from both SYNOW and $\text{PHOENIX}$. We find the spectrum to be dominated by blends of iron group elements Fe, Co, and Ni (as expected due to heavy line blanketing by these elements in the UV) and for the first time identify lines from C IV and Si IV in a supernova spectrum. We also find that classical delayed detonation models of Type Ia supernovae are able to accurately reproduce the flux levels of SN 2011fe in the UV. Further analysis reveals that photionization edges play an important role in feature formation in the far-UV, and that temperature variations in the outer layers of the ejecta significantly alter the Fe III/Fe II ratio producing large flux changes in the far-UV and velocity shifts in mid-UV features. SN 2011fe is the best observed core-normal SNe Ia, therefore analysis its of UV spectra shows the power of UV spectra in discriminating between different metalicities and progenitor scenarios of Type Ia supernovae, due to the fact that the UV probes the outermost layers of the Type Ia supernova, which are most sensitive to metalicity and progenitor variations.

arXiv comment15 pages, 12 figures. Accepted for publication in ApJ

References in corpus (24)

• Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation
• Comparative Direct Analysis of Type Ia Supernova Spectra. II. Maximum Light
• Metallicity Effects in NLTE Model Atmospheres of Type Ia Supernovae
• Constraints on the Progenitors of SNeIa & Implications for the Cosmological Equation of State
• Hubble Space Telescope spectra of the type Ia supernova SN2011fe: a tail of low-density, high-velocity material with Z<Zsolar
• Verifying the Cosmological Utility of Type Ia Supernovae: Implications of a Dispersion in the Ultraviolet Spectra
• Hubble Space Telescope studies of low-redshift Type Ia supernovae: Evolution with redshift and ultraviolet spectral trends
• Studying the Diversity of Type Ia Supernovae in the Ultraviolet: Comparing Models with Observations
• Light and color curve properties of type Ia supernovae: Theory vs. Observations
• Comparative Direct Analysis of Spectra of Type Ia Supernovae. I. SN 1994D
• Properties of the ultraviolet flux of type Ia supernovae: an analysis with synthetic spectra of SN 2001ep and SN 2001eh
• Metallicity Differences in Type Ia Supernova Progenitors Inferred from Ultraviolet Spectra
• The UV/optical spectra of the Type Ia supernova SN 2010jn: a bright supernova with outer layers rich in iron-group elements
• A Mismatch in the Ultraviolet Spectra between Low-Redshift and Intermediate-Redshift Type Ia Supernovae as a Possible Systematic Uncertainty for Supernova Cosmology
• Spectral Models of the Type Ic SN 1994I in M51
• Radioactively-Powered Rising Lightcurves of Type Ia Supernovae
• Carnegie Supernova Project-II: Using Near-Infrared Spectroscopy to determine the location of the outer ${}^{56}$Ni in Type Ia Supernovae
• A Physical Basis for the H-band Blue-edge Velocity and Light-Curve Shape Correlation in Context of Type Ia Supernova Explosion Physics
• Multi-layered Spectral Formation in SNe Ia Around Maximum Light
• Swift UVOT Grism Observations of Nearby Type Ia Supernovae -- II. Probing the Progenitor Metallicity of SNe Ia with Ultraviolet Spectra
• Theoretical Clues to the Ultraviolet Diversity of Type Ia Supernovae
• Goodness-of-Fit Tests DIFF1 and DIFF2 for Locally-Normalized Supernova Spectra
• A Photometric Analysis of the Relationship Between Type Ia Supernova UV Flux and Host Galaxy Metallicity
• Spectral Models for Early Time SN 2011fe Observations

Cited by in corpus (7)

• A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone can Explain Early-Excess Blue Flux in Some Type Ia Supernovae
• SN 2022acko: the First Early Far-Ultraviolet Spectra of a Type IIP Supernova
• From Out of the Blue: Swift Links 2002es-like, 2003fg-like, and Early-Time Bump Type Ia Supernovae
• The NewEra model grid
• SN 2021fxy: Mid-Ultraviolet Flux Suppression is a Common Feature of Type Ia Supernovae
• Direct Analysis of the Broad-Line SN 2019ein: Connection with the Core-Normal SN 2011fe
• The Ultraviolet Spectra of 2003fg-like Type Ia Supernovae