Re: jpeg images (fwd)

["Christopher L. Fryer" <clf@t6.lanl.gov>]

Ah... sorry...  I was envisioning a binary companion that merges in a
common envelope with the primary before the primary collapses.  The
scenario is similar to what we think happened to the companion of the
1987A progenitor.  Since it merged with the primary helium core, there
would be no companion to see now.

We need the binary if we want a 20-25Msun star to lose most of its mass
prior to collapse (one progenitor possibility for Cas A).  If the
progenitor is a really massive star, we don't need the binary.  so if we
stick with the low-mass variant of the progenitor, we will have to have
it.

If we have a binary, the mass loss will not be spherical and the
"wind-swept" media that the explosion goes through will be far from a
simple spherical scenario.

chris





On 11 May 2004, Jacco Vink wrote:

> Hi Chris & others,
>
> Shouldnt that be a fast moving star, or can it be completely blown away?
> I guess, it should be quite massive if ~10 Msun of mass has been dumped
> on it. Is there any chance that we could have missed a companian star?
> May be Rob Fesen can put some limits on this.
>
> As for the assymetries. It looks like Fe is asymmetric, i.e. no symmetry
> at all! Si is non-spherical, but here there seems to be the presence of
> jet-like ejecta (at least at one side).
>
> Jacco
>
> On Tue, 2004-05-11 at 16:38, Christopher L. Fryer wrote:
> > Hi all,
> >
> > Just to add some on the theory end.  We are running a large suite of
> > 3-dimensional explosion calculations with detailed abundance calculations.
> > Once we get the first set finished, I'll put them on the web.  But let me
> > say a few words of caution.  If the asymmetry is in the explosion, and not
> > the environment (e.g. the binary+windswept media) around the star prior to
> > collapse, then my money is on the iron having the biggest asymmetry.
> >
> > My intuition may be wrong here, I'll know more when we've finished this
> > suite of simulations and after we get a better handle on the progenitor,
> > but this looks a lot more like a binary affected environmnent to me.
> >
> > chris
> >
> >
> > On 11 May 2004, Jacco Vink wrote:
> >
> > > Dear all,
> > >
> > > I have put jpeg images of individual bands, as well as RGB color images
> > > on a webpage using the available 312 ks of observations:
> > > http://www.sron.nl/~jvink/casa_vlp . It includes one image suggesting
> > > the existence of a counter jet. However, I am not quite sure why the
> > > ratio of Si/Mg would bring out such evidence, may be the Jets may have
> > > purer Si abundance. At any rate it looks very interesting
> > > and worth pondering about. (A similar image I produced in
> > > http://arxiv.org/abs/astro-ph/0310518 -New Astron.Rev. 2004, 48, 61-67).
> > >
> > > Cheers,
> > >
> > >
> > > Jacco
> > >
>