Re: jpeg images

[John Hughes <jackph@physics.rutgers.edu>]

I seem to have missed some of the back and forth messages about 
Jacco's images (particularly some of Tracey's and Larry's early
today).  But if I've gotten the jist of the e-mails correctly, 
some people have questioned the identification of individual 
bands with astrophysically interesting quantities (e.g., continuum,
Mg, Si, etc.). Let me echo those concerns (and I'm sure Jacco will 
agree).  The energy bands containing "Ne" and "Mg" are also where 
Fe L-shell lines lie, so these images cannot be uniquely identified 
with a given species. We'll need to do spectroscopy to be sure.

OK, enough for the lecture.  Here's some fun stuff.

I downloaded all the data available, which totaled 570 ks 
as of late yesterday. Using the L2 events, I located the
position of the central point source and aligned all the
individual evt2 files to it.  The resulting total band image
is pretty spectacular!  The jet region shows a number of
fainter features, further out from the center than before.
The counter-jet unfortunately suffers from much worse PSF
(see casa_570ks_thrt_clippedmore_nomin.jpg at web site below).
(I wonder if we should have done 1/2 our observation at a roll
angle ~180 deg away from this one to image the counterjet
at the best resolution.  Too late now, though...)

Anyway Rob Fesen will be happy to know that there are a few other 
serendipitous point-like sources in the field of view located at:

Src 1:  23:23:43.213 +58:52:23.81 (appears in low energy X-rays)
Src 2:  23:23:57.261 +58:48:10.76 (appears in high energy X-rays)
Src 3:  23:23:51.402 +58:49:29.58 (maybe a faint knot?)

I also made a few 3-color images using the same energy bands as my paper
in 2000, with various scalings and clippings for the individual frames
to bring out faint features.  Note that I have not smoothed any of the
images.

You can find the broad-band fits images and jpeg files at my web site:

http://www.physics.rutgers.edu/~jackph/casa_vlp/

I will update these as I download more data.

Enjoy!
Jack
_______________________________________________________________________________
John P. Hughes          Department of Physics and Astronomy
                        Rutgers, The State University of New Jersey
                        136 Frelinghuysen Road, Piscataway, NJ 08854-8019 USA
                        Phone: 732-445-0980, Fax: 732-445-4343
                        http://www.physics.rutgers.edu/~jackph