ASTRO: NGC 3521

NGC 3521 is a very disturbed flocculant spiral galaxy in Leo about 35
million light-years distant. Redshift can be rather misleading giving a
distance of 54 million light-years. NED gives it a classification of
SAB(rs)bc;HII LINER while the NGC Project just notes it as Sb with H II
emission. I didn't pick up any H II emission in my image. Deep images
show a lot more to this galaxy than I was able to pick up. I took about
6 times the data used here, nearly all the color data was unusable as
was 18 of the 22 luminance frames. The last 12 months have been by far
the worst for imaging since I moved here 7 years ago. Actually all
color was unusable by normal standards. I just used the best single
frame of each color as using more just made things worse no matter what
I did. While I blame weather it was only half guilty. The other half
of frames lost were due to a very bright aurora going on two of those
nights that fogged the luminance frames and made the color balance
awful. No amount of normalization could handle the frame differences
which ranged from 450 (120 is normal) background to over 31,000 thanks
to that aurora I slept through. If conditions ever improve I'll try again.

Most sources attribute all the plumes due to the remains of several
dwarf galaxies it has consumed. One dwarf MGC 0016030 (near western
edge of my frame) has the same redshift so is likely a companion that
has survived (so far). Because of my very weak color data these plumes
are in mono only as the clouds and aurora drown out any hope of color
data for these faint features. Due to better than average seeing on the
4 luminance frames I did use I was able to pull out a lot of detail
right to the core of the galaxy. Much of the detail is "fogged" by all
the scattered stars in its halo from galaxies it has consumed. Only a
narrow region on the west (right) side is mostly clear of this "fog".
This is why the contrast suddenly improves in a small area. Really
makes it look strange. My processing cut through this "fog" to bring
out as much of the flocculant nature as I could. If I could have used
all 22 frames then I'd likely have processed for the plumes instead.

CGCG 141-072 is oddly classed as a dwarf irregular galaxy. Looks like a
barred spiral to me that has nice plumes coming off both arms. At over
10 times the distance of NGC 3521 it is small but not dwarf size. To
its north is LEDA 135771. It too is classed as a dwarf irregular. This
time it makes perfect sense. It is at the right distance and size to be
a dwarf companion of NGC 3521. Is it next to be consumed?

MGC 0015934 is classed as Sc. I don't have sufficient resolution at a
half billion light years to say if that is reasonable. Looks tighter
than that but this may be due to my resolution.

2dFGRS N368Z219 to the southeast is one strange galaxy. It has a very
blue bright core with faint, somewhat spiral plumes or arms. Again, my
color data missed these plumes. The Sloan image shows these as the same
blue color as the core. NED makes no attempt to classify it nor any
other galaxy in the image.

Arp liked to find significance in quasars near disturbed galaxies
thinking they were nearby objects ejected by these galaxies. A theory
he never could support to the satisfaction of the astronomy community
but never gave up. I can't find that he used this one in support of his
ideas even though it has far more quasars than average and is highly
disturbed.

Near the lower left corner is the rather common galaxy 2dFGRS N368Z212.
I'd not mention it but noticed its redshift distance by NED's 5 year
WMAP calculation is 666 million light-years. Is it the home of "The
Beast"? I was annotating this when that character made the news
resigning is job because his W2 carried the processing number of 666.

NED listed a ton of very faint galaxies with redshift data. I listed a
couple down to 23rd magnitude but omitted about 100 of them as not worth
the effort.

There are two very short asteroid trails that are noted in the annotated
image. They are likely short because they are at the end of their
retrograde motion and about to begin normal eastward motion across the
sky after we have passed them.

14" LX200R @ f/10, L=4x10' RGB=1x10' (All poor frames), STL-11000XM,
Paramount ME

Rick



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Another I see as a bit flat once I see it on the net. Didn't look at the compressed JPG only the TIFF and ther is a difference. Trying again.

Rick

I discovered something about very thin color images I didn't realize. While the TIFF looks fairly good as to noise in the dim areas the JPG process really tears up the noise making it far worse. I applied strong noise filters to the RGB data (leaving L alone) then recombined the TIFF and used quality 11 compression (very little) which results in a huge file but now the TIFF and JPG are about the same. Just learned something new about processing thin color data. Normally I do that only with star clusters which don't suffer the problem, at least in an obvious fashion.

Rick

Originally Posted by WA0CKY

Another I see as a bit flat once I see it on the net. Didn't look at the compressed JPG only the TIFF and there is a difference. Trying again.

Rick

"WA0CKY" wrote in message ...


I discovered something about very thin color images I didn't realize.
While the TIFF looks fairly good as to noise in the dim areas the JPG
process really tears up the noise making it far worse. I applied strong
noise filters to the RGB data (leaving L alone) then recombined the TIFF
and used quality 11 compression (very little) which results in a huge
file but now the TIFF and JPG are about the same. Just learned
something new about processing thin color data. Normally I do that only
with star clusters which don't suffer the problem, at least in an
obvious fashion.

Rick

WA0CKY;1240093 Wrote:
Another I see as a bit flat once I see it on the net. Didn't look at
the compressed JPG only the TIFF and there is a difference. Trying
again.

Rick


--
WA0CKY

Hi Rick. I like this galaxy. I hope you don't mind but I downloaded it and
played with it a little. I've learned a lot about processing in the last
year, so I thought I would try my hand at this and see how it would turn
out. I created a screen mask invert layer to bring out more of the faint
parts without blowing out the stars, and then used a soft color layer to
increase contrast and color. Then I used the shadow highlight filter (which
I don't normally use much) to bring down the highlights in the core of the
galaxy cause by creating the previous layers. Then I used carboni's
deepspace noise reduction to clean up the background a little. And finally,
I adjusted the blackpoint to get it back to your original, which I believe
was around 12. I included the result as an attachment. Tell me what you
think. If you don't like me messing with your photos, just tell me and I
will not do this again. Like I said, I just wanted to see what I could do
with it. Anyway, I hope you like it. It did bring out more detail.

George

Personally I don't care for such over the top processing but you're
welcome to process my images as you prefer them.

Rick

On 2/22/2013 7:48 AM, George wrote:


"WA0CKY" wrote in message ...


I discovered something about very thin color images I didn't realize.
While the TIFF looks fairly good as to noise in the dim areas the JPG
process really tears up the noise making it far worse. I applied strong
noise filters to the RGB data (leaving L alone) then recombined the TIFF
and used quality 11 compression (very little) which results in a huge
file but now the TIFF and JPG are about the same. Just learned
something new about processing thin color data. Normally I do that only
with star clusters which don't suffer the problem, at least in an
obvious fashion.

Rick

WA0CKY;1240093 Wrote:
Another I see as a bit flat once I see it on the net. Didn't look at
the compressed JPG only the TIFF and there is a difference. Trying
again.

Rick




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Prefix is correct. Domain is arvig dot net