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Arp 80 Lots of galaxies in IFN

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#1 Rick J

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Posted 28 December 2012 - 04:24 PM

Arp 80/NGC 2633 is located in northern Camelopardalis with a red shift distance of about 100 million light-years. Other distance estimates range from 89 million light-years to 108 million light-years with a mean value of 96 million light-years. The latter is in surprisingly good agreement with the redshift value. Arp put it in his category for spiral galaxies with large high surface brightness companions. His comment reads: "End of one arm heavy; absorption break in same arm near nucleus." Note it doesn't mention the "high surface brightness companion." Could that be because it doesn't exist? This has to be one of the most puzzling entries in his atlas. I'd think a high surface brightness companion would be easy to spot but where the blankety-blank is it? The VV catalog seems to add my confusion when it reads: "3 or more galaxies with one or two 'bridges' (at the left). All nearly in contact. Bordered by an arc above and below and still further above by a wide spiral arm. ... The upper arc is terminated by zigzags, or by a chance projection of a remote nest." Until that last sentence I thought I might have the wrong galaxy but it does show a nice squiggle at the end of the upper arm. That arm is quite a bit brighter than the other arm. The UGC makes the most sense when it says of Arp 80: "Arp's class 'galaxies with one heavy arm' appears more appropriate." Amen to that! I believe the absorption break Arp speaks of is at the other end from the squiggle right where it meets the core region. At least I see a strong dust band cutting straight across the arm there which is a very unusual feature. But I can't fathom the companion or companions Arp and the VV catalog mentions. Best I can do is the "zigzag" or "nest" at the end of the arm that the VV catalog mentions. Both the NGC Project and NED class it as SBb.

It does, however, have a companion. It is LEDA 213530 about 3 minutes to the south and a bit east. Far from being on an arm it is apparently a true companion having exactly the same redshift, 2160 km/s. NED classes it as Im. It is quite blue as are a surprising number of the galaxies in this image.

Below it is yet another companion NGC 2634. It is classed by NED as E1: and simply as E by the NGC Project. Usually elliptical galaxies are composed of old red stars but this one has outer shells of blue. The POSS plates also show it brighter in blue than red light. Continuing south yet we find yet another group member, NGC 2634A. NED classes it as SB(s)bc? sp. The sp means it has spectral lines. It is apparently an edge on barred spiral. It certainly has some bright knots of activity in it. The shells of NGC 2634 are usually an indication it is digesting a rather large meal after cannibalizing another galaxy in the past. I find its shells more interesting than Arp 80. Arp has a class for such shell galaxies but didn't include this one though to me its shells structure is better defined than some he did include. All notes at NED agree it is not interacting with NGC 2634A.

Those 4 are the only ones with any redshift data but there are other interesting galaxies in the image that I marked in the annotated image. MAILYAN 035 is a very low surface brightness, and very fuzzy spiral galaxy that is also very blue. The designation is from the Mailyan Dwarf Galaxy Catalogue. So apparently it is a small galaxy much closer than the previously mentioned galaxies. Though without redshift data this is only a guess.

Every object NED lists in the field has been annotated. Most with a ? for distance. A few that would seem reasonable for NED to know about aren't listed. Probably because those that are are either from the 2MASS catalog of 2 micron objects which omits galaxies without 2 micron radiation which usually means lots of warm dust, or they are objects with strong ultraviolet radiation. These are noted by UvES. Often these are quasar candidates though they can be just stars with unusual UV radiation and even galaxies. One that is certainly a galaxy is at the top of the image left of center. The others are star-like but without redshift data I can't tell if they might be quasar candidates or not.

The entire field is full of IFN, galactic cirrus. Unfortunately my color data is somewhat noisy do to clouds so it looks rather noisy. This image was taken over a couple nights but still was severely hurt by clouds. This is my last January 2012 image. Weather allowed me to capture only 5 objects that month and most of those were taken under far from ideal skies. February wasn't any better nor was most of the year. It isn't ending any better than it began.

Arp's image:
http://ned.ipac.calt.../big_arp80.jpeg

14" LX200R @ f/10, L=8x10' R=4x10' G=3x10' B=2x10', STL-11000XM, Paramount ME

Full frame at native 1" per pixel
http://www.spacebant...ntid=4408&stc=1

Annotated
http://www.spacebant...09&d=1356683005

Rick

Attached Thumbnails

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#2 WhistleStop

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Posted 28 December 2012 - 07:32 PM

Great collection Rick..almost need my Gravol...its so dizzying :)
Happy New Year
Cheers
Lynn

#3 Rick J

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Posted 29 December 2012 - 06:07 PM

This is a good field for those with a wider FOV and clear skies to spend more time to bring out the faint IFN. At 74 degrees good polar alignment is a big help.

I had to google Gravol. It's Dramamine on on this side of the border.

I have an inner ear problem due to being too close to a big explosion at about age 8 that damaged the balance organ in my right ear (and nearly deafened that ear) so often need it though this field didn't do that to me.

Rick

#4 Jim Thommes

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Posted 29 December 2012 - 07:26 PM

Rick,
It is a marvelous field. It's also a pretty reasonable view of the IFN.


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