'What is the progenitor system of the nearby Type Ia SN 2014J?'


Type Ia supernovae (SNe Ia) are the thermonuclear explosive
end-products of white dwarfs. SNe Ia are primary cosmological distance
indicators and a major contributor to the chemical evolution of
galaxies, yet we do not know what makes a SN Ia.
There are two basic families of models leading to a SN Ia, the single-
degenerate model (SD) and the double-degenerate model (DD). In the SD
scenario, a WD accretes mass from a hydrogen-rich star companion
before reaching a mass close to the Chandrasekhar mass and going off
as supernova. In the DD scenario, two WDs merge.
Radio (and X-ray) observations can potentially discriminate between
the progenitor models of SNe Ia. For example, in all scenarios with
mass transfer from a companion (i.e., SD scenarios), a significant
amount of circumstellar gas is expected, and therefore a shock is
bound to form when the supernova ejecta are expelled. On the contrary,
the DD scenario will not give rise to any circumstellar medium close
to the progenitor system, and hence essentially no prompt radio
emission is expected.
I will present the deepest radio observations ever of the type Ia SN
2014J in M82, aimed at probing both SD and DD scenarios for this
nearby supernova, using JVLA, eMERLIN, and EVN observations. The
evidence from our radio non-detection for 2014J strongly points in the
direction of a DD scenario for this supernova.
03/07/2014 - 14:30
Dr. Miguel Ängel Pérez Torres