Cr Research

1.0 – 0.6 head-on collision in 3d

Cody — Thu, 11 Feb 2010 19:54:15 +0000

A 1.01msun WD collides with a 0.64 WD.

I wrote a 3d plugin for my visualization routine. Here’s an example for a 1.0 msun white dwarf colliding with a 0.64 msun white dwarf.

The apparent roiling on the surface of the stars may be an artifact of the particle nature of the simulation, or of the way I’m drawing contours at fixed opacities. In either case, it looks way cool and should make for some really good PR material.

Spatial Distributions Paper Accepted

Cody — Fri, 18 Sep 2009 21:27:49 +0000

An illustration of the Doughnut Method for a SN Ia host.

Our paper on type Ia supernova spatial distributions and how they can be used to age date SNe Ia has been accepted for publication in ApJ. You can read a draft of it here.

Prompt Ia Supernovae are Significantly Delayed

This is the paper wherein we develop a new observational technique that builds on previous work by Andy Fruchter and others.

The Gort Principle

Cody — Fri, 18 Sep 2009 19:14:40 +0000

A simulation of the collision of a 0.8 solar mass white dwarf (bottom) and a 0.6 solar mass white dwarf (top).

Another Crack at Visualizations

Cody — Fri, 28 Aug 2009 20:14:43 +0000

Bob Greene of LANL has turned his viz talents on our SPH simulation outputs. Here is a sample of what his tools can do.

Pictured here is a single frame from a collision scenario. The two spheres embedded in the larger cloud are simply the cores of the constituent white dwarfs that have yet to merge. We hope to eventually make animations using this technique.

Collisions Paper Accepted

Cody — Fri, 28 Aug 2009 02:45:16 +0000

Our paper on white dwarf collisions, On Type Ia Supernovae From The Collisions of Two White Dwarfs, has been accepted by MNRAS. It should be published within a month or so.

Wolfram|Alpha

Cody — Thu, 02 Jul 2009 15:55:51 +0000

I use this almost every day now and I recommend anyone who relies heavily on a TI-89 or just occasionally wants to compute something check it out.

Working at LANL this Summer

Cody — Thu, 02 Jul 2009 15:38:54 +0000

I started at LANL this week and will be working here for the remainder of July on reintegrating the changes made to our version of SNSPH into the main code branch.

A Few More Visualizations

Cody — Tue, 26 May 2009 19:43:38 +0000

The text on the color bars didn’t survive the jpeging process too well.

Doughnut Method & the LSST

Cody — Tue, 19 May 2009 04:59:52 +0000

Evan is a member of the LSST team, and so now our “doughnut method” for constraining type Ia SNe will be a small part of the science goals of the LSST.

To read more about the “doughnut method“, check out our paper on it, Prompt Ia Supernovae are Significantly Delayed which has been submitted to ApJ Letters.

Collision Poster

Cody — Tue, 19 May 2009 04:13:22 +0000

A poster of one of our white dwarf collision simulations will be on display outside of the SESE office very soon. It will probably also be on display somewhere on the Astronomy floor of the F-wing. Here is the final mockup from Susan Selkirk.

Depicted here, two CO 0.6Msun white dwarfs collide with an impact parameter of 1/2 the white dwarf radius. They detonate as a supernova and end up looking something like Tycho’s SNR shown in the background of the poster. This simulation consisted of approximately 800,000 particles and used a 13 isotope reaction network.