• Maeda, Keiich
• Takahashi, Tadayuki
• Fukazawa, Yasushi
• Katsuda, Satoru
• Ueda, Yoshihiro
• Bamba, Aya
• Tamagawa, Toru
• Röpke, Friedrich K.
• Enoto, Teruaki
• Diehl, Roland
• Summa, Alexander
• Terada, Yukikatsu

Abstract

Type Ia Supernovae (SNe Ia) are key objects for the present cosmology as the most mature standard candles. It is important to verify theoretical models of SN Ia explosions observationally. Since emissions from SN Ia are mainly drived by the radioactive sources generated in the explosion, gamma-ray observations are the key for the study. We performed a soft gamma-ray observation of the near-by SN Ia, SN2014J, with the hard X-ray detector (HXD) onboard Suzaku satellite at 77 ± 2 days after the explosion. After careful treatments of X-ray contaminations from ultra-luminous X-ray source in the M82 galaxy, non X-ray background events, Cosmic X-ray background emission and the Earth's albedo, we found gamma-ray signals are measured from SN2014J at 2 sigma confidence with the flux at (1.2 ± 0.7) × 10<SUP>-4</SUP> ph s<SUP>-1</SUP> cm<SUP>-2</SUP> in the 170-250 keV band. The flux ratio between the continuum and the line from <SUP>56</SUP>Co is sensitive to the ejecta mass and might distinguish progenitor models between single and double degenerate scenarios. Our Suzaku data of continuum emission and line emission reported by INTEGRAL satellite has been examined with this relation but could not distinguish these models. However, thanks to the high sensitivities of the HXD around 200 keV in the shorter exposure than INTEGRAL, the Suzaku observations clearly exclude explosion models with heavier <SUP>56</SUP>Ni mass than 1 solar mass....

Topics

• impedance spectroscopy