Object of the Week January 27, 2013 UGC3697 (The Integral Sign Galaxy)

[Jimi Lowrey]

UGC 3697 AKA "Integral Sign Galaxy"

Camelopardalis

RA
07 11 22
DEC
+71 50 11

MAG 13.5

Type Sd Pec

UGC 3697 is a unique and rare type Super Thin galaxy with a strange stellar warp. I have been fascinated by it since I first learned about it many years ago.

What has caused this galaxy to be twisted in this stage shape? It was long thought that the 12.7 Mag UGC 3714 that is South East of UGC 3697 was the cause. At 127,000 LY away it was thought to have had a close encounter with the Integral Sign galaxy in the past, but recently astronomers using the VLA have mapped the HI in UGC 3697and now think that the twist in UGC 3697 is caused by a minor interaction with a dwarf galaxy. In the Image below from the VLA you can see on the South East side of UGC 3697 the faint core of the dwarf galaxy that has been striped by UGC 3697.

ugc3697fullcolor_lo.jpg

They say that if it had interacted with UGC 3714 it could not have kept such a thin appearance it would have been more pulled apart and distorted. Also in a few million years it will go back to a normal flat shape that the twist is just a transit event.

ugc3697 Block.jpg

Be sure to check out this strange unique galaxy next time you are out while you can the twist will be gone in a few million years.

"GIVE IT A GO AND LET US KNOW"

GOOD LUCK AND GREAT VIEWING!

[MarcE]

Hi Jimi,
also one of my favourite super thins!
I several time observed it with 15 and 16 inches. Very thin, indirect quite long and the northern part is a bit brighter (direction to the nearby star) than the southern part. I could not detect the typical "integral sign" form. I will try it next time with my 24incher.
UGC 3714 is an easy UGC and can be observed with direct vision.
Clear skies (which is not very often these days in Germany)
Marc

[Uwe Glahn]

Hi Jimi,

the typically bends at the end were always difficult to see with my old 16".
With the 27" the more easy W bend is easy to see, the bend at the E could also be detected, but is much more difficult.

16", 257x
UGC3697.jpg

[FaintFuzzies]

Great and interesting object. Here is my latest observation at Shot Rock under NELM 7.2 skies.

22” at 184, 255 and 328x – Considerably bright thin glow with well-defined edges. Appears as a flat integral sign galaxy. The west tip curve a bit more than the east tip. A couple 15th magnitude stars lies on each side. PA = 75 and 2.7’ long.

http://www.faintfuzzies.com/OR-Nov022010-SR.html (about 3/4 of the way down)

[Paul Alsing]

Hi Jimi,

This guy was on the list when Big Jim and Ana Chandler hosted myself, Steve Gottlieb, Debbie Searle and Jeff Gortatowsky in your absence. Overall it was a poor week for observing ;>(, but for the 4 hours I managed that week, this object was the main highlight, looking just like the photo. We spent a lot of time viewing this galaxy.

From my sparse notes, the west end of this long and skinny galaxy has a hook, and an overall "lumpy" texture, and as it fades away on this end it seems to have either a dim star or a brighter knot right at the end. The eastern end just sorta fades away.

All in all, a great and unique view.

[Jimi Lowrey]

Paul,

I'm not sure what that is on the West end? Looks like a H II knot but it could be a star? I will check it out with a filter to see if its a H II knot next time I am at the telescope and will report back.

Steve Gottlieb found the 1967 ASS paper by Margaret and G.R. Burbidge (Who found this Object) and it has a old Image taken by the 82" telescope at McDonald of UGC 3697 in Feb 1962.

t2png.jpg

They called it GB 1

[Steve Gottlieb]

I was surprised to see that SIMBAD still uses GB 1 as the primary designation for the Integral Sign galaxy.

In 1972, there was a short paper in ApJ, 171, 13 by Richer, Sharpless and Olson that displayed 8 HII regions in the galaxy, including two at the west end. Harvey Richer, one of the authors of the paper, sent me an e-mail in June 2011 mentioning that he had read my article in S&T on superthins (which includes the Integral Sign) and attached a copy of this paper!

[Jimi Lowrey]

Very interesting Steve it looks like what Paul saw was the HII knot on the west end of GB 1.

GB 1.jpg

[Paul Alsing]

I'm pretty sure we all saw it, Jimi, we talked about it at length...

[Don Pensack]

I've seen this in my 12.5", with "best" magnifications of 183X and 228X, skies of SQM 21.5.
I noted a faint thin line with evidence of curve at mostly one end and very slight brightening in center.
At the time I made the notes, but later observations didn't confirm my notes, I thought it looked like
a small, much fainter, version of NGC4656.
My notes point out that this is really an object for a large scope when details are desired in the image.
I didn't find it particularly hard, though it was fairly faint, and it definitely didn't look like an integral sign.
I tried several years earlier with an 8", but couldn't find it.
So is 10" or 12.5" a threshold aperture?

[Jimi Lowrey]

I revisited GB 1 (Integral Sign Galaxy) Last night I wanted to see the H II knot on the end of the galaxy that Paul was talking about in his post. The transparency was not the best and seeing was so so not bad but not the best ether. I picked up GB 1 at once with direct vision at 375x with my finder eyepiece. I then bumped up the power to 488X and the H II knot was popping in and out. I then went to 610X and the knot was there direct vision and in moments of good seeing like Paul said the knot looked like a stellar point. The galaxy looked very dim and mottled and had a speckled appearance in monuments of the best seeing at this power. I also noted a brightening in the galaxy just to the East of the center of the galaxy (see image below) The brightening looked like a small bar to my eye and was just a little brighter than the rest of the galaxy. After looking at the paper (ApJ, 171, 13 by Richer, Sharpless and Olson) that Steve posted I see that I was seeing another H II star forming region in this most peculiar galaxy. I did not see the striped dwarf galaxy core on the South east end but I did not spend much time on it.

G B 1 inverted.JPG