Earlier this winter I was able to capture some data on another of Arp's 4 galaxies with Jets, Arp 150 which is part of the 4 galaxy group known as Hickson 95 and is located about 500 million light years away, 10 times further than M87. Unfortunately I was clouded out and only got one third the data I considered the minimum needed. I planned on getting the rest but forgot to put it on my list. I didn't realize I'd not gotten the data until too late. It didn't help that I had imaged the first night at 0.5" per pixel and never had a night after that, that was up to the needed seeing quality until I forgot about it. So the image below is very thin and noisy. Color data was very poor. It will have to do until next year.
I found this text comment about the group but the image it refers to was missing. "This group is characterized by the showy interaction between the elliptical a and the spiral galaxy c. The northern spiral arm of this last galaxy is strongly distorted towards galaxy a and forms a luminous blob at the connection. A bridge of matter connect also the nucleus of the spiral with the elliptical, so that a sort of tongs-like structure is formed. The two remaining galaxies of the group (b, and d) are both radio-emitting spirals (Menon & Hickson 1985). Finally we note the small galaxy north-east to galaxy b, which is not included in the Hickson list and is probably an elliptical."
I believe a is the top galaxy c, the middle one (appears double to me) with the arc a, the lower left b and d lower right. The suspected elliptical is very orange in color in my lousy color data as a distant elliptical "should" be. I could find nothing on it however, not even a catalog name. While the curving arc is easily seen in my image I didn't get enough data to show the jet very well. It is the linear feature coming out of the "middle spiral point just right of the core of the top elliptical. It shows better in Arp's photo.
http://nedwww.ipac.caltech.edu/level...ig_arp150.jpeg
In comparing the two I'm mystified by a faded object in my image. His photo shows a star-like object in the arc right above (in Arp's image -- left in mine) the big elliptical galaxy. While it appears to be bright enough to see clearly in my image it only shows very faintly. I don't know why. There was a super nova in this pair in 1973 but Arp's photo is nearly 20 years prior to that event. I can see it faintly in my red data as well as the luminosity data but not in green and blue yet Apr's image appears to be in blue light. But when I combined them into a color image it vanished. I can't even be sure this is the same object as Arp imaged.
The other two galaxies in the group are MCG +01-59-046 Sc spiral (right) and MCG +01-59-048 Scd spiral (left). Both are at about the same half billion light years as Arp 150.
Since most of the field is rather empty thanks to my severe under exposure I've posted only cropped versions, color and mono as it shows more detail. If you just must see the full image it is at:
http://www.spacebanter.com/attachmen...tid=2505&stc=1
Other galaxies in the image are anonymous as far as I can determine. Image scale 0.5" per pixel.
14" LX200R @ f/10, L=4x10' binned 1x1, RGB=2x10 binned 2x2, STL-11000XM, Paramount ME
Rick
08-July-2009, 10:22 PM
The real Arp 150
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