Search for New Paths to Type Ia Supernovae

2015 Fiscal Year Final Research Report

• Project/Area Number: 24540227
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: The University of Tokyo
• Principal Investigator: HACHISU Izumi 東京大学, 総合文化研究科, 准教授 (90135533)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: Ia型超新星 / 連星系の進化 / 恒星風 / 白色矮星 / 距離指標 / 光度曲線 / 質量降着 / チャンドラセカール限界質量

Outline of Final Research Achievements

Recent observations of Type Ia supernovae suggest that some of the progenitor white dwarfs had masses up to 2.4-2.8 soloar masses, highly exceeding the Chandrasekhar mass limit. We present a new single degenerate model for Type Ia supernova progenitors, in which the white dwarf mass possibly reaches 2.3-2.7 solar masses. Three binary evolution processes are incorporated; optically thick winds from mass-accreting white dwarfs, mass stripping from the binary companion star by the white dwarf winds, and white dwarfs being supported by differential rotation. The white dwarf mass can increase by accretion up to 2.3 solar masses from the initial value of 1.1 soloar masses, being consistent with high-luminosity Type Ia supernovae, such as SN 2003fg, SN 2006gz, SN 2007if, and SN 2009dc. We also suggest that the very bright super-Chandrasekhar mass Type Ia supernovae are born in a low-metallicity environment.

Free Research Field

天体物理学