ASTRO: Arp 223

Arp 223 is entered in his catalog under amorphous spiral arms. It is
also known as NGC 7585 and is in the constellation of Aquarius just
below the Circlet of Pisces. Red shift puts it at about 145 million
light years away. Most sources say it is the result of a merger of two
galaxies but do admit they find no hint of the second galaxy saying it
must have been some time ago and it is now fully absorbed. They note
the presence of NGC 7576 10 minutes to the southwest (also in my image)
but dismiss it has being too far away. But again admitting that it too
is about 145 million light years distant with virtually the same red
shift as Arp 223. It is a ring galaxy which often is the result of an
encounter. Neither shows any tidal streamer that you'd expect from an
encounter so probably the experts are right, still I have to wonder a
bit. But see its near twin Arp 222 to be posted next.

I screwed up taking this one. I've had NGC 7592, a triple interacting
Arp "wanna-be" galaxy on my to-do list for several years. It is just 15
minutes north of Arp 223. Somehow in my muddled middle of the night
brain (cloud alarm woke me at 1 a.m. to say the sky has cleared get
imaging) I thought I needed to put it high in the field to pick up NGC
7592 but it should have been low! ARGH. I could have captured all
three if my brain had been working on even half its neurons. Maybe next
September.

I did catch 4 asteroids in the image. In the upper left corner partly
out of frame is (8943) Stefanozavka at magnitude 18.4, slightly to its
west is 2005 SK58 at magnitude 19.3. Down near the lower left corner
is 2000 AY204 at magnitude 17.6. Toward the lower right corner, under
NGC 7576 is (14021) 1994 PL20 at magnitude 18.3. Magnitudes are
estimates by the minor planet center and can be off quite a bit it
seems. You may wonder why the second asteroid has no number. Asteroids
get a number only after their orbit is fully determined. This usually
takes at least one full orbit. That hasn't yet happened for 2005 SK58.

Several catalogs list an 18.7 magnitude quasar just southwest of Arp 223
a bit over about 1.4 minutes away and just on the edge of the galaxy as
seen in my image. Since I easily picked up a 19th magnitude moving
asteroid an 18.7 magnitude quasar should be very obvious. I don't see
it, nor do I see it in Arp's image of the galaxy. Either it is much
fainter than listed or the position is wrong. It's [VCV2001]
J231758.8-043954 and yes the coordinates in its name match the position
where I don't see it, just about 10" NE of a tight unequal double star.

This field is too close to the Milky Way's dust so not covered by the
SDSS. This means there's little information on this entire field. Only
one other object has a red shift given (besides the vanished quasar).
It is a small galaxy nearly 10 minutes west and slightly north of Arp
223. It is just beside a dim star to its upper right. It is listed at
2.1 billion light years. So while there is a paucity of galaxies
compared to my normal posts that isn't Because I'm not going as deep,
they just aren't there.

With this image I've finally moved into processing September images.
Next up will be Arp 223 which is nearly a twin of this one so I'm taking
it slightly out of imaged order.

Arp's image is at:
http://nedwww.ipac.caltech.edu/level...ig_arp223.jpeg

14" LX200R @ f/10, L=4x10' RGB=1x20'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".