Arp 49/NGC 5665 is in Bootes. It's distance is a bit difficult to pin
down. Redshift puts it about 113 million light-years distant but a
recent Tully-Fisher measurement says only about 65 million light-years.
A 40 year old Tully measurement agrees to its redshift. For now I'll
go with the redshift distance as being more likely closer to reality.
Arp put it in his class of spirals with small, high surface brightness
companions on the arms. His comment reads: "Appearance of wake from
stellar object in eastern arm." This stellar object is NGC 5665A.
Older sources consider it a separate galaxy, newer say it is part of the
galaxy not a separate one. One paper suggests this galaxy is the result
of a merger that happened about a half billion years ago. Another
concludes the arms couldn't be tidal in nature and its distortions are
natural to the galaxy, not due to outside influences. The field is
rather barren of any candidates that could have distorted it so that
part is likely correct. But whether this is a merger or just a
naturally weird galaxy seems still up for debate. There is one more
galaxy at the same distance as Arp 49 in the image, LEDA 4421246 to the
north. It's a dwarf and likely too small to bother Arp 49 in any way
though it is possible it donated many of its stars to Arp 49 long ago.
My color data was severely hurt by varying clouds and haze so is a bit
suspect. Still it seems to agree fairly well to the Sloan image so I'll
go with what I have for now.
Arp's image:
http://ned.ipac.caltech.edu/level5/A...big_arp49.jpeg
14" LX200R @ f/10, L=4x10', RGB=2x10'x3, STL-11000XM, Paramount ME
Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".