Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae

Details Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae

2010-06-22

arxiv.org/abs/1006.4391v3

Astroph.J. Letters 722 (2010) 157-161

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

5 pages, 1 figure, accepted for publication in ApJ Letters. (v3 matches the accepted version, clarified following the refereee

Scientific paper

Type Ia supernovae are generally thought to be due to the thermonuclear explosions of carbon-oxygen white dwarfs with masses near the Chandrasekhar mass. This scenario, however, has two long-standing problems. First, the explosions do not naturally produce the correct mix of elements, but have to be finely tuned to proceed from sub-sonic deflagration to super-sonic detonation. Second, population models and observations give formation rates of near-Chandrasekhar white dwarfs that are far too small. Here, we suggest that type Ia supernovae instead result from mergers of roughly equal-mass carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar mass remnants. Numerical studies of such mergers have shown that the remnants consist of rapidly rotating cores that contain most of the mass and are hottest in the center, surrounded by dense, small disks. We argue that the disks accrete quickly, and that the resulting compressional heating likely leads to central carbon ignition. This ignition occurs at densities for which pure detonations lead to events similar to type Ia supernovae. With this merger scenario, we can understand the type Ia rates, and have plausible reasons for the observed range in luminosity and for the bias of more luminous supernovae towards younger populations. We speculate that explosions of white dwarfs slowly brought to the Chandrasekhar limit---which should also occur---are responsible for some of the "atypical" type Ia supernovae.

Affiliated with

Also associated with

No associations

Rating

Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sub-Chandrasekhar White Dwarf Mergers as the Progenitors of Type Ia Supernovae will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-276730