G'day Paul,
I will admit that I have a definite NGC 2442 obsession......I keep a hundred images of it on disk, at various scales, and at various wavelengths, so as to be able to compare and contrast them.
I can't seem to disprove the very interesting idea that the ultra-faint light extending from the longer and narrower of the two main arms of NGC 2442 , when seen in your very deep image, extends a long way outwards into the field, away from the bright portion of the galaxy. This faint optically-luminous material just doesn't look like cirrus to me.
Therefore, I am wondering what your recent image of N2442 would look like if the very outermost extremely-faint regions of this galaxy could be emphasized even more;
no need for a "pretty picture" here, just maximum contrast and brightness.
The only other amateur image I know of that shows the outermost extremely-faint material well is by Martin Pugh.
Ryder et al, in a 2001 paper (reference: 2001, ApJ,
555, 232) presented an image of this galaxy which was made from three co-added UK Schmidt plates......and you blokes are imaging as deep as that, if not deeper, which is very good work!!
Here is a link to their UKS image:
http://iopscience.iop.org/0004-637X/...53313.fg2.html
Accordingly, I am thinking of sending the URL of your image to Professor Ron Buta (University of Alabama), a man who essentially "wrote the book on bars in galaxies"(in other words, the modern classification and understanding of barred spirals is in good measure due to Buta's research).
I think he may find some interest in the anomalous/peculiar outermost material that is well seen in your image. The long bar-like structure from which the two main Spiral Arms emanate is also rather unusual; I am wondering if it also has a ring structure which is seen in a foreshortened aspect.
Other professional astronomers who might be interested in your image include Chris Mihos and Greg Bothun, who in 1997 modelled the interaction origin of this galaxy's current appearance; and also Koribalski and Ryder and colleagues, a mainly Australian team who discovered a highly unusual
intergalactic cloud of neutral hydrogen gas near NGC 2442:
http://arxiv.org/pdf/astro-ph/0103099.pdf
From what I can see, there has been little professional follow-up of the unusual intergalactic gas and of the unusual morphology of this galaxy, except for the recent
very very weak paper about NGC 2442 that I provided a link to in your thread.
This situation is fairly typical for the more cautious of the professional astronomers; they seem content to plod along, adding the merest infinitesimal increments to the existing knowledge, and do not wish trouble their minds by following up the implications of peculiarities and anomalies.
I certainly do appreciate the large amount of effort and expertise that you put into getting the best possible image of a galaxy. Indeed, it is definitely getting to the stage where expert astro-imagers like you are reaching depths on galaxy images that could well lead to new discoveries.
Cheers,
Robert
Here is another co-added Schmidt Plates image from the UKS. I am not sure if it is the same exposures as the one that was presented in the paper:
http://www.aao.gov.au/images/deep_html/n2442_d.html
