Arp 203/NGC 3712 is located about 90 million light-years away in the
constellation of Ursa Major just across the border from Leo. In fact
the south edge of my image is only a few seconds of arc into Ursa Major.
Arp put it in his category for galaxies with material ejected from
nucleus. So what material is he referring to? I have no idea. His
comment says "Faint plumes coming off both ends of bar." Is this the
material? NED classes it as SB? as does the NGC project.
The "bar" is rather broken up. It consists of three bright parts. A
lower elongated piece and two round pieces north of it oriented at an
angle to the lower piece. Further north are two faint condensations.
The northern one brighter and designated by the SDSS as a separate
galaxy with no red shift given. Arp 203 does have one obvious
companion, or galaxy at about the same distance near the same line of
sight. It is SDSS J113119.85+283125.0 at 83 million light years. It's
a rather featureless galaxy that NED makes no attempt to categorize.
Both are rather small galaxies. Since it is undistorted I doubt it is
the cause of the plumes seen coming from Arp 203. Could it be a merger.
The multiple bright blobs in the core would seem to make this a
possibility. I found no papers discussing anything about its plumes
other than pure descriptions. Though I didn't search very deep. Still
it seems to be a poorly studied galaxy.
NED and the SDSS have some communication errors involving this one or
maybe the problem is solely with the SDSS. In any case the SDSS doesn't
recognize NGC 3712 in the NED data base nor at their own finder web
page. In fact put in the coordinates for NGC 3712 and it says the field
is not in the survey! Put in the coordinates for its position for NGC
3712 which it enters as SDSS J113109.36+283359.3 which is the position
of the lower of the three blobs that seem to define the bar and then it
finds it. Just a few seconds of arc north and it returns the out of
field error. It also lists a rather bright 20th magnitude galaxy a bit
east of Arp 203 that does exist but is about 24th magnitude not 20th
which had me going for a bit. There are other errors but I didn't
pursue them, just cussed and went on.
In the upper left corner you can find ZwCl 1129.4+2858, a galaxy cluster
of unknown distance with 68 members in an 11' field. The label marks
the center. Most that I see are to the upper left of that position.
But redshift distances of galaxies within 5.5 minutes of the center all
have very different values ranging from 2.3 to 5 billion light-years.
At least the galaxies with redshift values are just a line of sight
group rather than a true cluster of gravitationally bound galaxies. If
there's a true cluster here redshift values aren't disclosing it.
This was taken early in the morning of April 15, 2010 so I am now
officially a year behind in my processing
Arp's image
http://nedwww.ipac.caltech.edu/level...ig_arp203.jpeg
14" LX200R @ f/10, L=6x10' RGB=2x10'x3, STL=11000XM, Paramount ME
Rick
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Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".