English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Despite their prominent role in cosmography, little is yet known about thenature of type-Ia supernovae (SNe Ia), from the identity of their progenitorsystems, through the evolution of those systems up to ignition and explosion,and to the causes of the environmental dependences of their observedproperties. I briefly review some of those puzzles. I then focus on recentprogress in reconstructing the SN Ia delay time distribution (DTD) -- the SNrate versus time that would follow a hypothetical brief burst of starformation. A number of measurements of the DTD over the past two years, usingdifferent methods and based on SNe Ia in different environments and redshiftranges, are converging. At delays 1<t<10 Gyr, these measurements show a similar1/t power-law shape, with similar normalizations. The DTD peaks at the shortestdelays probed, but there is still some uncertainty regarding its precise shapein the range 0.1<t<1 Gyr. At face value, this result supports Ron Webbink's(1984) idea of a double-degenerate progenitor origin for SNe Ia, but thenumbers currently predicted by binary population synthesis models must beincreased by factors of 3-10, at least. Single-degenerate progenitors may stillplay a role in producing short-delay SNe Ia, or perhaps all SNe Ia, if there issomething important missing in the current modeling efforts.

Type-Ia supernovae: new clues to their progenitors from the delay-time distribution