Re: 1Msec pictures

[Tracey DeLaney <tdelaney@astro.umn.edu>]

Hi everybody,

I would like to slightly amend Larry's observations here.  The really
bright knot at the "base" of the southernmost counterjet finger (located
at RA offset=40 and DEC offset=-20 on Larry's gif) is part of the forward
shock structure with a similar spectrum to the rest of the exterior
continuum-dominated filaments.  In fact, the forward shock cuts through
this region just as it does for the NE jet.  The elongated tangential
filament at the base of the northernmost counterjet finger and the bright
knot at the base of the central counterjet finger are also
continuum-enhanced.  So one of the "bends" is not really a bend at all,
just a different structure.  I don't have anything to say at this time
about the "flaring" at the end of the southernmost finger.  In order to
not accidentally mix together things that are overlapping but unrelated,
it might be useful to make a Si equivalent width image or do some
tomography to separate jet stuff from not jet stuff.  

Before making any statements about fine structure in the counterjets, I
would ask the question: What would the NE jet look like under similar
viewing conditions? e.g. What if the pointing center were on the other
side of the chip from the NE jet?  The resolution in the SW is about 2
arcsec at 1.5 keV.  Also, given the greater absorption in the region, we
may be preferentially seeing higher energy photons.  The psf radius
increases slightly at higher energies thus lowering the effective
resolution by about another half arcsecond.  This is all before convolving
out to 5 arcseconds to presumably increase S/N.  As a test, if your
high-pass filter were run on the ROSAT image for the NE jet, would you
predict the fine-scale structure that we now know is present from the
Chandra image?

Ok, end of my stream of consciousness,
Tracey

On Thu, 27 May 2004, Lawrence Rudnick wrote:

> in the meantime, the counterjet has encountered a little 'trouble'.
> the southernmost of the three filaments has a couple of bends, and
> a likely flaring at the end, as seen in the attached gif.  this
> is broadband, convolved to 5", overlaid with contours of the same
> image run through a simple high pass filter. this could be a little
> problematic, or interesting, depending on your view on life.  not so
> easy to bend a dense clump travelling ballistically, without
> immediately disrupting it. and, since these 'counterjets' seem to
> have little or no finestructure, not clear that a simple ballistic
> picture of clumps being successively ejected was a good way to think
> about this anyway, although fesen's work shows that there were
> definitely ballistic ejections in this region. in images that are
> not so burned out, it also looks like the middle filament can be
> traced interior to the outer shock, and if this is right,
> shows some gentle curvature, as well.
>    enough stream of consciousness, enjoy the pics.
> 
> lr
>