ASTRO: Arp 207

Arp 207 is located in western Draco near the border with Camelopardalis.
Redshift puts it about 100 million light-years away. Arp put it in
his category for galaxies with material ejected from the nucleus. He
seemed to think some features we now consider to be tidal in nature to
be material that somehow the core ejected; rather than stars, dust and
gas pulled from the outer reaches of galaxies by tidal forces. He left
no comment on this one making his feelings on this one somewhat vague
other than its category.

I found very little in the literature. Vorontsov and Velyaminov put it
in their category for galaxy pairs with satellites on a stem -- Bottle
forms. They describe this form as having "...dwarf satellites connected
to the primary by a short thin filament, mostly normal to the surface of
the latter. This recalls a mushroom sitting on its stem. It is
noteworthy that most primaries appear to be spheroidal, not spiral."
However Arp 207 (VV58) is not listed as being typical of the group,
likely because the primary is likely a spiral. So they consider it a
pair of interacting galaxies, one a dwarf.
http://adsabs.harvard.edu/cgi-bin/bi...6AS...28....1V -- a
42 meg PDF so be warned.

The UGC catalog has a different opinion. It is UGC 5050 in their
catalog and carries this notation: "Asymmetric -- Short jet-shaped
feature in position angle 50." No mention of a dwarf galaxy being
involved. But the position angle bothers me. Normally position angle
is measured from celestial north (top of my image) through east (left in
my image). This gives me a position angle for the jet of about 226
degrees. If measured from the end of the jet to the main galaxy that
would be about 46 degrees. Odd way to do it however.

I prefer the VV catalog take on this one. Note that the entire system
is slightly curved with the core slightly north of a line connecting
both ends of the system. This would indicate some sort of interaction.

To the northeast (seen in the enlarged cropped image) is CGCG 350-026.
NED has nothing on it. Is it related to Arp 207? It certainly looks
odd. Reminds me of a Star Trek logo of a distorted sort. Is that a
star north of the core or part of the galaxy? An odd V shaped (greater
than symbol) comes in from the east ending in a bright region west of
the core. Unfortunately I was unable to find an image of this one on the
net with greater resolution than my shot. For now I'm calling it the
Star Trek Logo Galaxy.
http://www.beyondhollywood.com/uploa...-Trek-Logo.png
rotated 90 degrees clockwise. Or maybe a NASA logo
http://en.wikipedia.org/wiki/File:Nasa-logo.gif .

NED has no distance data on any other galaxy in the image nor are many
of them even listed. This far north, 76.5°, coverage is very poor.

Arp's image with the 200" telescope has south up while I post my images
north up. The notch in Arp's images usually indicates north in his
atlas (at least one exception). Note how the field star partly lost in
the overexposed galaxy appears out of round in his image. I can't
explain this other than an illusion due to how the emulsion he used
reacts to "flashing". This effect caused an asteroid track in Arp 192
to appear curved. The star is round in my image.

Arp's image:
http://ned.ipac.caltech.edu/level5/A...ig_arp207.jpeg

14" LX200R @ f/10, L=4x10' RB=2x10', STL-11000XM, Paramount ME

Rick

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