Type Ia Supernovae: Rates and Progenitors
Date
2015-09-01
Authors
Masikiv Heringer, Epson Thiago
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Abstract
Thermonuclear (Type Ia) supernovae are excellent distance indicators, due to their
uniform peak brightness. They are also important contributors to the chemical
evolution of galaxies since their explosions supply large amounts of iron peak
elements to the interstellar medium. However, there is no consensus on the
progenitor systems of these supernovae. As a result, different delay times from the
formation of the binary system to the supernova have been proposed. Whether the
observed rate of supernova Type Ia in early-type galaxies supports a progenitor
channel with one or two degenerate objects has been disputed. While the
predominant old population found in early-type galaxies supports longer delay
times, the presence of recent star formation might indicate the opposite. In this
work, we employ a double-burst model to account for the relative contribution of
both populations. We show that for a DTD ∝ t^−1, convolved with star formation
histories that are relevant for early-type galaxies, the supernova rate is independent
of a host galaxy’s colour. Our results indicate that a DTD with no cutoff is
preferred, thus favoring the double-degenerate scenario.
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Keywords
Supernovae, Type Ia, Red Sequence