Non-LTE spectral analysis and model constraints on SN 1993J

view Abstract Citations (80) References (56) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Non-LTE Spectral Analysis and Model Constraints on SN 1993J Baron, E. ; Hauschildt, P. H. ; Branch, D. ; Austin, S. ; Garnavich, P. ; Ann, Hong Bae ; Wagner, R. M. ; Filippenko, A. V. ; Matheson, T. ; Liebert, James Abstract We present non-LTE synthetic spectra for a time series of observations of SN 1993J obtained on 1993 March 30-31, April 7, April 13-15, and June 13 UT. The spectra are dominated by hydrogen Balmer lines; neutral helium lines, which have been nonthermally excited; and Fe II features. The density profile evolves from an extremely steep "brick wall" structure with an equivalent power-law index of about 50 on March 30 to a more typical SN II profile with a power law index of about 10. The early spectra are well fitted by a solar composition of metals, although an enhanced abundance of helium is required in order to fit the neutral helium lines. By June 13, the photosphere has receded deep into the helium layer, although there appears to be a layer of hydrogen at higher velocity. The distance is estimated for each epoch. While consistent results are found for spectra obtained in the month of April, the spread in distances from March to June is quite large. Our value for April is μ = 28.0 +/- 0.3 mag, consistent with the recent Cepheid distance to the host galaxy M81. We also compare our results to other implementations of the expanding photosphere method. Publication: The Astrophysical Journal Pub Date: March 1995 DOI: 10.1086/175347 Bibcode: 1995ApJ...441..170B Keywords: Astronomical Models; Balmer Series; Helium; Hydrogen; Local Thermodynamic Equilibrium; Metallicity; Neutral Gases; Spectrum Analysis; Supernovae; Abundance; Distance; Iron; Numerical Analysis; Photosphere; Red Shift; Astronomy full text sources ADS | data products SIMBAD (3) NED (2)