ASTRO: Arp 288 More plumes

Arp 288 is a triple galaxy system in the very northeast corner of Virgo
about 320 million light-years away. Arp put it in his catalog under
Wind Effects. Apparently referring to the northern member of the trio,
NGC 5221. It has some faint but huge plumes. South of it is the odd
galaxy pair of NGC 5222. It consists of a small blue spiral and a
larger golden elliptical galaxy. Arp's comment refers to NGC 5221 when
it says: "Streamers in both directions from edge of spiral. Why he
included the pair that is NGC 5222 I'm not sure. They are related in
that their redshift is about the same but neither shows distortion that
could easily explain NGC 5221's plumes.

NED classes NGC 5221 as Sb. I'd have thought the plumes would earn it a
pec designation but apparently not. The spiral itself is quite ordinary
looking though I suspect that is due to our highly tilted viewing angle.
One note at NED says it is a barred spiral.

NGC 5222 is an odd pair of galaxies, a small blue Sa spiral and a far
larger elliptical (E). The spiral has some distortion, best seen on the
Sloan or Arp images. Redshift puts them about 3 million light years
further away though this is likely due to their motion about a common
center of gravity rather than a real difference. Still these two have
virtually the same redshift indicating a closer relationship. The
papers I found consider the elliptical as the cause of NGC 5221's
plumes. I'm not so sure. The distortion to the much smaller and likely
nearer blue companion is not nearly as great yet such a tiny galaxy
should be greatly distorted. Though if the interaction is just starting
this would be the case. Still I'm not convinced.

The other large galaxy in the image is NGC 5230, a M101 like spiral. It
has a red shift distance of 324 million light years. One note at NED
says it might be distorted by the elliptical NGC 5222. Again I'm having
problems with this. Shouldn't the elliptical show some distortion after
interacting with two large and one small galaxy. I can understand the
small one but not the other two. Would it be more likely that NGC
5221's plumes are due to it interacting with NGC 5230 in the distant
past? Seems more likely to me. Nothing I found in the literature
suggests it however.

There are quite a few other galaxies in the group in my image. The
largest after these three is NGC 5226, the small spiral north of NGC
5221. At a redshift distance of 346 million light-years it could be a
distant member though again this might be due to its motion relative the
the rest rather than a true distance difference.

All possible members with redshift data are shown by name in the
annotated image. Those without a catalog designation are too distant to
be considered possible members of the Arp 288 group.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp288.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".

Rick,

that's a good field , lots of small but detailed galaxies. I have put it on
my list.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Arp 288 is a triple galaxy system in the very northeast corner of Virgo
about 320 million light-years away. Arp put it in his catalog under
Wind Effects. Apparently referring to the northern member of the trio,
NGC 5221. It has some faint but huge plumes. South of it is the odd
galaxy pair of NGC 5222. It consists of a small blue spiral and a
larger golden elliptical galaxy. Arp's comment refers to NGC 5221 when
it says: "Streamers in both directions from edge of spiral. Why he
included the pair that is NGC 5222 I'm not sure. They are related in
that their redshift is about the same but neither shows distortion that
could easily explain NGC 5221's plumes.

NED classes NGC 5221 as Sb. I'd have thought the plumes would earn it a
pec designation but apparently not. The spiral itself is quite ordinary
looking though I suspect that is due to our highly tilted viewing angle.
One note at NED says it is a barred spiral.

NGC 5222 is an odd pair of galaxies, a small blue Sa spiral and a far
larger elliptical (E). The spiral has some distortion, best seen on the
Sloan or Arp images. Redshift puts them about 3 million light years
further away though this is likely due to their motion about a common
center of gravity rather than a real difference. Still these two have
virtually the same redshift indicating a closer relationship. The
papers I found consider the elliptical as the cause of NGC 5221's
plumes. I'm not so sure. The distortion to the much smaller and likely
nearer blue companion is not nearly as great yet such a tiny galaxy
should be greatly distorted. Though if the interaction is just starting
this would be the case. Still I'm not convinced.

The other large galaxy in the image is NGC 5230, a M101 like spiral. It
has a red shift distance of 324 million light years. One note at NED
says it might be distorted by the elliptical NGC 5222. Again I'm having
problems with this. Shouldn't the elliptical show some distortion after
interacting with two large and one small galaxy. I can understand the
small one but not the other two. Would it be more likely that NGC
5221's plumes are due to it interacting with NGC 5230 in the distant
past? Seems more likely to me. Nothing I found in the literature
suggests it however.

There are quite a few other galaxies in the group in my image. The
largest after these three is NGC 5226, the small spiral north of NGC
5221. At a redshift distance of 346 million light-years it could be a
distant member though again this might be due to its motion relative the
the rest rather than a true distance difference.

All possible members with redshift data are shown by name in the
annotated image. Those without a catalog designation are too distant to
be considered possible members of the Arp 288 group.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp288.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".