Faint arm in NGC2841

[Fabiomax]

Hi

By Stefano Conti have taken over two nights in the galaxy NC2841.
We used two different setups:
I: rc 8 "dslr for rgb
stefano: acf f7 CCD SBIG 10xme for luminance.

In my picture (RGB) has already highlighted a halo, which seemed interesting ,because I had not seen in other images.
In the picture of Stephen (L) there is also an additional ring and more material in the ring.
We combined the pictures and the link that is out. Initially we had hopes of a stream stars. I thank Ken Crawford and J. Gabany to seeing the pictures.
It seems that we have highlighted weak arms in the galaxy.
If so it would be very interesting, changing the morphology of this galaxy. We are happy if someone has news about it.
I put some of the yield map with dslr that I had a good result. I am doubtful that only one galaxy from NED to 22.6 mag Maybe a little too much.
In my photo there was a problem of off-axis guide gradient I felt that night. For the future I have to move it.

http://www.astrofabiomax.it/ngc2841.html

Cheers,
Fabiomax

[Nicola]

Beautiful image Fabiomax, very good collaboration with Stefano! keep on trying!

[TrevorW]

Well done Fabio a great image a fine example of what can be acheived with modest equipment in the right hands

[strongmanmike]

Excellent bit of work Fabio, very interesting and fantastic for an 8" scope.

Modern imaging is amazing, after so many years working with film in the past, I find what is possible today with a 6 or 8 inch scope to be almost unbelievable.

Mike

[Paul Haese]

Nice work Fabio. Lots of really find detail in the arms.

[Fabiomax]

Thanks again!
in truth, the luminance was made with a 12 inch. But we're pretty happy with the result.
Hello,
Fabiomax

[madbadgalaxyman]

Fabio,

Your very interesting image of N2841 illustrates the fact that "if you image deeper or sharper or with a wider field, you are bound to discover something new".

[Fabiomax]

Thank you Robert,
Fabiomax

[multiweb]

Very nice indeed. Great details and colors. :thumbsup:

[atalas]

Top stuff Fab!

[madbadgalaxyman]

Fabio,
I think that you have found something very interesting in your image. I will have to find out by checking the literature of professional astronomy whether or not it qualifies as a discovery. I suspect that the outer Very Faint optical material in N2841 was already known by professional astronomers, but its structure and properties may not be well understood.

Your imaging effort is part of a trend in amateur astronomy in which increasing numbers of amateurs image deep enough to find new things in the outermost regions of galaxies.

The unusual outermost optically-luminous material in
NGC 2841 is very faintly and indistinctly visible in many amateur images, but most images are not deep enough to show the detailed structure of this "anomalous outermost material".

There is only one other image I know about that shows this Anomalous Outermost Material properly. This is the image by
CXIELO Observatory. See this URL:

http://www.cxielo.ch (http://www.cxielo.ch/)

While the disk structures of spiral and S0 galaxies are approximately planar, it is very very common to find that spiral and S0 galaxies have bends, warps, and tilts, in their outer regions.

In the professional literature, any obvious bending away from the principal plane of a disk galaxy is called a Warp.
The amazing thing about warps is firstly that there are many different kinds, and secondly that the large variety of observed non-planar phenomena is not understood by professional astronomers.

In the last two years I have been undertaking a detailed study of non-planar phenomena in disk galaxies. Based on this experience, there are at least two possible interpretations of what is seen at the two ends of the major axis of NGC 2841, in your super-stretched image. The three-dimensional structure of this galaxy, at the extreme ends of the major axis could be as follows:

(1) There could be two bends of the "planar" disk, away from the principal plane of the galaxy, at the two extreme ends of the major axis, with the two bends being oppositely directed.

(2) The entire Faint outermost part (annulus) of this galaxy could be a ring which is at an angle to the ring that is the bright part of this galaxy. In other words, the inner bright galaxy would be at one position angle and the the outer faint part of this galaxy could be at another position angle. Thus, NGC 2841 might occupy two planes, rather than one.


I should point out to you that neither of these two types of bends and tilts is a rare phenomenon, in the population of spiral galaxies.......
In particular, oppositely directed bends/warps at the two extreme ends of the major axis of a galaxy are very common; for instance M31 and our own Galaxy have this sort of warp!
Howevever this is not to say that anybody really understands what causes this sort of phenomenon.
In the professional literature, there has been some limited study of the two-sided warps and bends, but there has been very little study of what could cause a spiral galaxy to occupy more than one plane.
I fact, a good number of individual spiral and S0 galaxies only make sense if they are modelled as being composed of a number of different rings (planes) at various angles to each other .
(Note: It is actually very tricky to figure out the 3-dimensional structure of a galaxy from its 2-dimensional image; there is no easy way to do this......)


The Unusual Outermost Material in N2841 is also visible in the ultraviolet image taken by the GALEX satellite, which I attach.
In this image, far-ultraviolet light displays as blue and near-ultraviolet light displays as Yellow :

91651

In this ultraviolet image, there is plenty of blue light visible outside the bright optical body of N2841, that is, there is far-ultraviolet emission here. In the outer regions of galaxies, this FUV emission can only come from young & luminous OB stars; so there is recent star-formation happening here.
________________


I have just found a radio (21cms) image of the HI (cold neutral atomic hydrogen) layer in NGC 2841, and this confirms that there is a bend or tilt away from the plane of this galaxy:

91652

This 21 cm wavelength image of the cold Hydrogen Gas layer in this galaxy is taken from The HI Nearby Galaxy Survey, and intensity of the grayscale corresponds to the amount of hydrogen gas in the line-of-sight.
The bright inner disk of gas corresponds in space to the bright optical disk of NGC 2841 , but note how the outer gas is at a different position angle. It looks more like the entire outermost part of this galaxy is at a different position angle to the inner part, and that this galaxy occupies two distinct planes!! Alternately, the gas layer is bent away from the principal plane, at the two ends of the major axis.

cheers,
madbadgalaxyman

[Fabiomax]

Do you think that we, in our small, we went in search of stars stream! Your report is very interesting, among other things, expands our knowledge on the dynamics of galaxies. We would like to contact us to future developments. The originals are available. Yes, The slope of the visible matter in HI is different than the image in the optical. Now I feel even Stefano, with whom I worked for this image. Thanks,:)
Fabiomax

[madbadgalaxyman]

Yeah, those diagrams in the astronomy textbooks are wrong; you know, those diagrams showing a spiral galaxy as a thin flat and planar object!
Thin and flat, yes, but planar....NO!

In fact, strict planarity is rare in disk galaxies.

I have prepared an Atlas of edge-on S0 and Spiral galaxies that show a bewildering variety of non-planar bends, warps, and tilts. There are about 4 types of warp that are recognized in the scientific literature, but this is only a fraction of the various types that exist in the real universe.

A third possibility for the actual 3-dimensional structure of what we observe (in two dimensions only) in the outermost regions of NGC 2841 would be a detached ring that surrounds the bright optical body of this galaxy, but which is well separated from the main optical body.

Polar rings are a well-known and well-studied phenomenon in galaxies, but regarding the existence (and plausibility) of Outermost detached rings that are in a similar plane to the rest of a galaxy.......
I don't think anyone knows what is the actual incidence of these objects, but with the new trend towards ultra-deep imaging by amateurs, we will soon find out.

[Ken Crawford]

Very nice work indeed . . . .

This is a very good example of going deep with good calibrations detecting amazing structures not may have not been seen before. We have the advantage of owning our own eqipment and we can stay on a target as long as we like!

These structures are faint but large so with good transparency and dark skies you can detect these type of structures with good low noise cameras and smaller systems.

I detected a stellar stream with a 5" refractor!

This is one of the topics I will be speaking on at the upcoming AAIC. I believe we are in the golden age of Pro-Am work . . .

Again, Congrats on a very fine result!

Kindest Regards,

[Fabiomax]

Thanks for the comment Ken. It 's a pleasure to read it. Besides being a landmark, you're also a really nice person. Iwould love to to be at the conference, but Australia is very far away for me . But I'm not complaining, having recently been at Cedic, really interesting as well for this wonderful adventure that is the imaging of the deep sky.
Cheers,
Fabiomax