ARP115

Arp 115/UGC 6678 is a triple galaxy about 440 million light-years distant located in the very northeast corner of Leo. Arp put it in his category of elliptical or elliptical-like galaxy close to and perturbing a spiral galaxy. In this case, there are two elliptical galaxies and a very odd spiral. The spiral, UGC 6678 is classed as Sb. I find it peculiar but it doesn't carry the peculiar designation. Though whether the two ellipticals have anything to do with it seems debatable. These three are part of a much larger group at the same distance. Some of which are in shown in my annotated image. Others extend north and south out of my image.

UGC 6678 (the blue spiral) may have grown due to chowing down on many dwarf galaxies in the group resulting in its current somewhat odd shape. Or it might be due to interaction with some of the others in the group. The one to the northwest corner of the enlarged cropped image is a possibility as it is rather peculiar itself. It is KUG 1140+266/LEDA 1772579. Neither "elliptical" seems the least distorted. They haven't even distorted each other though appear on top of one another. Arp's comment on the pair of ellipticals reads: "Object slightly S of northern gal. is just perceptibly nonstellar." This would indicate it wasn't cataloged at the time of Arp's catalog. The small one is classed as S0 rather than elliptical which appears reasonable to me. NED doesn't classify the larger galaxy. Looks more like a barred spiral to me than an elliptical. That isn't seen in Arp's image, however. It is also known as PGC 036379 and several other designations. The small S0, however, has no separate designation other than that of one of the other two and a secondary letter or other designation.

In the annotated image you will note several families of galaxies inhabit the field. The largest group is that of Arp 115 but others reside at 1 billion light-years at the top center, 1.7 to 1.8 billion light-years across the field and 1.3 to 1.4 across the field. Only a handful don't fit one of these groups. There is one galaxy cluster whose position matches that of a galaxy. The cluster, MaxBCG J175.78981+26.45578, is said to be 3.3 billion light-years distant and contains 14 galaxies across an unknown radius. One possible member is south of it right beside a second, slightly brighter galaxy. Oddly the brighter one not only has no redshift data, it isn't in NED at all! Usually, it is rather large, low surface brightness, blue spirals that get this disrespect but this time its a tiny dim reddened galaxy of indeterminable type.

You've probably noticed the right side of the image is out of focus. This is another image taken when the camera's set screws had worked loose. Most nights it would hold position but on warmer nights it would fall away on one side causing this problem. Likely a few more of these as I didn't catch the problem for some time. I have to look at the data soon after it is taken rather than months later.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp115.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP115

ARP116

Arp 116 belongs in Arp's class for elliptical and elliptical-like galaxies close to and perturbing spirals. In this case, it is M 60 that is the elliptical and NGC 4647 that is the spiral. It is slightly sloshed with the core off center toward M60 as if pulled there by its gravity. Is that really the case? Redshift puts NGC 4647 at about 80 million light-years and M 60 at 66. But non-redshift measurements have a median value of 55 million light-years for both. These are part of the Virgo cluster which is well known to for galaxies having a wide difference in redshift due to the strong gravity well created by so many galaxies in a small area. Redshift is not considered very reliable both because the cluster is rather close (averaging about 60 million light-years) and due to the wide variance of their widely varying speeds unrelated to distance. One study shows that the spiral must be behind M60 since none of its absorption features can be seen against M 60 as would be expected if it were in front. Since M60 has virtually no such features their lack against the spiral is expected even if it is in front of the spiral. How far they are apart is still unknown. With their difference in redshift, any passage by each other would be brief hardly giving time for any interaction to show. While it might distort a spiral arm slightly I doubt it could be the cause of the sloshing of NGC 4647's core. But this is only my surmise. It could be that since the side toward M 60 is bright due to being seen through M60 the fainter parts of NGC 4647 are hidden and it really isn't sloshed at all.

Measuring the size of an elliptical galaxy like M 60 is difficult as the edges just fade away meaning the longer the exposure the larger the size will be. I measure it somewhat larger than NED's value and get a size of about 145,000 light-years assuming a distance of 55 million light-years. While #60 in Messier's list it was first discovered by Johann Koehler on April 11, 1779. The next day Barnaba Oriani saw it. Messier saw and recorded it on April 15, 4 days after Koehler saw it. It could be so many saw it about the same time as a comet was known to be in the area at the time.

I measure NGC 4647 at a bit under 40 million light-years. It was discovered by William Herschel on March 15, 1784. It is in the Hershel 2 400 observing list.

There are no other major galaxies in the frame. Most of the galaxies lie far beyond the Virgo Cluster or are very small dwarf galaxies. Telling them apart visually is often difficult so I did prepare an annotated image showing red-shift distances. I'm writing this years after taking this image and I have no idea why Arp 116 is so low in my frame. If centered, NGC 4637 an S0- galaxy, would be visible. Instead only its very northern part ekes into the lower right corner. It was discovered by R. J. Mitchell on March 1, 1854. Also, due to my leaving no notes about taking this one I have no idea why I used only one 10 minute frame for each color.
Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp116.jpeg

14" LX200R @ f/10, L=6x10' RGB=1x10', STL-11000XM, Paramount ME

Related Designations for ARP116

ARP117

This is a reprocess of an image taken back in 2009. My processing toolkit was limited as was my ability to use what tools I had. So it was time to redo it after I looked at it and got an instant yuck reaction in my stomach. I cheated by starting with a partly processed TIFF luminance image and since the color data looked good but for color balance I used it as I had processed it the first time except to adjust color balance some, mainly to remove airglow that tends to be strong at my latitude. Also, I wasn't doing annotated images back then. There was enough else going on I needed to go into that I had skipped in the original post 6 years ago.

This is a two for one Arp image that contains both Arp 79 and Arp 117. Arp 79 is listed by Arp under the category for spiral galaxies with high surface brightness companions. But there's no such companion. Arp's only comment on the object refers to the two star knots in the southern arm saying; "Small separation between two knots in arm." There is an orange field star in the other arm but I don't see how that looks anything like a companion galaxy either. Some have said he is referring to the brightening of the arm where those two star knots are located but since he refers to them and the brightening looks nothing like a companion I can't imagine that was his intent. It does have a strange feature, a straight bar of blue stars that appears separate from the galaxy seen below the two star knots. It's far from being of high surface brightness but could be considered a companion I suppose. I find nothing on it.

The right of two star knots in the arm is SDSS J141007.08+173647.6 which NED does call a galaxy rather than part of a galaxy but I've seen many such star knots listed this way so I don't put a lot of credence into that classification. The other star knot isn't listed at NED at all nor is the bar. Seems there's lots of mystery to this one. While it looks like a small spiral it is actually pretty normal sized at 70,000 light-years. It's just its distance that makes it seem small. It is sometimes known as NGC 5490C (NGC 5490 is at the bottom of my image) and is classified as SB(s)bc.

Arp 117 is listed by Arp under his classification for elliptical-like galaxies close to and perturbing spirals. Thus by his classification, the small galaxy is perturbing the big one. Arp apparently sees this as a warping of the spiral for which he notes: "Flattening of spiral's nucleus appears to be in a different plane than the arms." I'm not so sure I see what he is talking about. The core is very bright with a bright but short bar. Does he see this as a spiral seen edge on inside a face on set of arms? Other than this I don't see what he is talking about. While both galaxies have the same redshift and thus likely about the same distance from us it also could be their relative motions are actually quite different but their distance difference covers this up. I'd think there'd be distortions in the smaller companion as well as the spiral. I don't see that the companion is anything but very normal looking. It is IC 982, a SA0+ galaxy and the spiral is IC 983 an SB(r)bc galaxy. Note that except for the pseudo ring structure its classification is the same as that of Arp 79 even though they appear very different.

Arp 117 (both galaxies) was discovered by Stephane Javelle on May 27, 1891. IC 982 is about 80,000 light-years across while the spiral IC 983 is absolutely huge at over 325,000 light-years dwarfing everything around it.

Note in the annotated image there are many dwarf galaxies with a redshift indicating they are part of the same group. Many having almost exactly the same redshift in fact.

The other major galaxy in the image is NGC 5490 that for some reason I didn't get entirely on the frame. It is listed simply as an Elliptical galaxy and has a very similar redshift to the two Arp systems. Indicating it is likely part of the same group. It was discovered by William Herschel on March 14, 1784. It is in the second Herschel 400 observing program. I can't directly measure its size on my image since it is partly out of the frame. Using NED's diameter it would be about 125,000 light years in size using a distance of 250,000 million light-years determined by mostly type 1A supernova measurements though redshift places it a bit closer and thus smaller. It may be its own group as there are other galaxies around it with redshifts a bit less than that of the two Arp systems.

Arp's image of #79
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp79.jpeg

Arp's image of #117
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp117.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10' binned 3x3, STL-11000XM, Paramount ME

Related Designations for ARP117

ARP118

Arp 118 reminds me a lot of Arp 244 also known as the Antenna Galaxies. Though there are no long tidal tails and only one of the galaxies is a spiral. This pair is nearly 4 times more distant at just under 400 million light years but the left spiral shows the same loop of knots along one edge that NGC 4038, the upper spiral in the antenna galaxies shows.

The left member of Arp 118 carries two NGC numbers 1141 and 1143. The right member also has two numbers 1142 and 1144. The reason for two entries for each is that NGC 1141 and 1142 were recorded by Albert Marth on October 5, 1864 but his position for them was off, putting both 40 minutes north of their correct position. Then on November 17, 1876 Édouard Stephan recorded them at their correct position. Dreyer, not realizing the error recorded both in his catalog that became the NGC. Since NGC 1143 and 1144 had the accurate positions they are usually used for this pair. I will use them as well.

NGC 1143 (right galaxy) is classed as S0 pec (Ring A) and NGC 1144 as S pec (Ring B). Arp though has them under his "Elliptical or Elliptical-like Galaxies close to perturbing spirals". I assume 1143 is the elliptical-like galaxy and 1144 the perturbing spiral. Though it appears to me its the "perturbing spiral" that has been most perturbed. Its arms are wildly distorted and then there's that blue arc of monster star clusters on the side toward the other galaxy.

There are two other possible members of this group but they appear to be staying just far enough away not to be distorted -- yet. One is LEDA 1150350 to the upper right of the other two. Just above NGC 1144 (left galaxy) is a near star-like blue galaxy SDSS J025512.06-001032.9 with a redshift distance that puts it at the same distance and thus likely a dwarf member of the group. While NED gives a separate positional galaxy entry for the blue arc most, including Arp, consider the arc part of NGC 1144. In fact, his comment on this entry reads: "Arms and loops seem attracted to the E galaxy."

At the bottom of the image just slightly left of Arp 118 is a small spiral SDSS J025518.00-001824.7 with no distance data. Just to its right is a "star". It is listed as a galaxy ASK 037126.0 at a redshift distance of 1.63 billion light years. Obviously not a member of the group!

Toward the top of the page left of center is a galaxy with two faint loops for arms one above and one below the core. They must be due to some interaction in the past. It is LEDA 1154257 at about a half billion light-years. Too far to be involved with Arp 118. To its right and right against the upper edge is the spiral galaxy PGC 010988 540 million light years. These two may possibly have interacted in the past as both show some possible distortion.

There are two asteroids in the image as well though due to my processing to best show the structure of Arp 118 they are rather faintly seen. The one above Arp 118 halfway to the top and a bit right of the group is (42989) 1999 TO245 at magnitude 18.8 slightly further right but only slightly higher than Arp 118 is (47716) 2000 DQ25 at magnitude 19.6.

Arp's image is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp118.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP118

ARP119

An Arp 3 fer in Pisces!

Arp 88 (Very small pair, in cropped image above center to the right)
This one falls in his category Spirals with large, high surface brightness companions on their arms. There is very little on this one. It is also known as PGC 004728/VV 445 and listed as a galaxy pair in the VV catalog as well as the Arp Atlas. The larger spiral carries the designation 2MASX J01190524+1228240 so is an IR source. NED gives no distance data nor attempts to even classify it as a spiral. Even its magnitude estimate is blank! I'm literally drawing a blank on this one. Even the note at NED is very strange. There's only the one. I guess when as a researcher you draw a blank this is what you write:
"One of the rare cases where the companion at the end of a spiral arm is also a spiral. Here, a chain of H II regions encircles the massive condensation thus forming a small spiral ripening at the periphery of the larger one and liable to gemmate." I really doubt it is reproducing by budding as his comment would seem to indicate! The note does date to 1977. Likely he is being descriptive in a more poetic way than Arp. http://adsabs.harvard.edu/cgi-bin/bib_query?1977A%26AS...28....1V
It's a 41 meg download, I didn't download it just trusted NED's note.


Arp 119 (The obvious pair)
Arp put it in his category of Elliptical and elliptical-like galaxies close to and perturbing spirals. The southern galaxy, MCG +02-04-021, is the more interesting. It shows two radial velocities with an emission knot between the core and northern galaxy showing a radial velocity about 800 km per second faster. NED classes it as SBc with an AGN while in another place it says Sdm: LINER. A note says SA(r)cd pec. I don't really see the ring many papers mention but otherwise, I agree with this last classification.

The northern galaxy is MCG +02-04-022. It is classed as E? This seems odd to me as well. A note at NED says: "Our images show a clear stretching of this galaxy along the direction towards Arp 119S. We observe two definite components: an inner region (a < 16") where the surface brightness profile seems of de Vaucouleurs type, and other external region (a > 18") where the {mu} profile looks like a exponential profile. However, the geometric profiles do not show evidence for disky structure. At this point, the galaxy could be classified as E3 ... The total ... color is representative of E, S0 types." That I can agree with. Its radial velocity is about half waybetween the two measurements for the southern galaxy. It does appear they are interacting.

Arp's comment on this pair reads "Some material seems attracted, some repelled." Using the northern galaxies radial velocity the distance to this pair is about 640 million light-years.

The Odd looking blue galaxy below Arp 119 is MRK 0983. It is classed simply as Peculiar though appears to be a distorted spiral. I wouldn't be surprised if it isn't actually two interacting galaxies but I have nothing to support this but what I see in my image. Its radial velocity puts it at about 630 million light-years. This likely means it is part of the Arp 119 system and may have tangled with one or both Arp 119 members.

Arp 48 (lower left corner if full image -- inset in cropped image)
The third Arp entry is Arp 48 to the southeast of Arp 119. Arp put it in his category: "Spiral Galaxies with low surface brightness companions on arms." I put it in the lower right corner of the enlarged and cropped image as there wasn't much in that corner but it is a bit confusing to put it there. When I imaged Arp 119 I knew Arp 88 was coming along for the ride but missed Arp 48. In fact, I imaged it separately a couple months later never realizing I already had it. Good thing as the intentional image had poor seeing compared to the Arp 119 image. It wasn't until I went to process this image I noted Arp 48 but thought it one Arp missed until I looked it up. The pair is also known as CGCG 436-026.

Individually the lower galaxy carries the IR source designation of 2MASX J01195923+1220377 and shows a radial velocity and shows a radial velocity distance of 635 million light-years. So it too is likely part of the same group as Arp 119. NED has no notes on it nor does it attempt to classify it. It does say this: "Low surface brightness companion on end of arm. M51 Type." Now, which of three objects is this referring to, the golden galaxy, the odd blue knot or galaxy by the cut-short arm or the galaxy to the south? I see no hint of an M51 type arm structure reaching over any of these. I could sort of make this work for the smaller blue fuzz patch, though that seems more likely a part of the northern galaxy's mostly missing arm.

The northern galaxy with one good and one not so good arm is another IR source listed as 2MASX J01200039+1220537 and also as PGC 4789. NED has absolutely nothing on it. Not even a magnitude. Odd, as it appears to be the major galaxy here. Arp certainly considered it the main one. It also appears that he considered the fainter blue fuzz patch as the companion on the arm and ignored the southern galaxy entirely. His comment reads: "Some material seems attached, some repelled." This "repelling" comment may be due to the sudden cut off of the arm. Without a redshift, it is impossible to say with certainty the northern galaxy is even related to either of the other two. I'd like some confirmation here. Neither the blue knot that's Arp's "companion" nor the golden galaxy just east of the northern spiral are in NED at all. This is a very poorly researched area it would appear.

There's an obvious galaxy cluster below Arp 48. This is NSCS J01195 at 4 billion light-years. NED shows it as containing 64 members. It extends south out of this field of view. While I got all of it in the later image of Arp 48 the seeing is so bad it isn't worth processing. This view will have to do.

The only other object in my image with a redshift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a redshift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.

The obvious asteroid in the image is (243847) 2000 VA62 at an estimated magnitude of 17.7. This magnitude seems reasonable.

A second asteroid in the image is more difficult to find. It is near the right edge a bit below center just above a typical white star. It shows as a horizontal line about 7 pixels long so is very short. It is the slow moving asteroid (146703) 2001 VY112 at an estimated magnitude of 19.5. It appears only slightly fainter than the far brighter (243847) 2000 VA62 because its very slow motion greatly increases its exposure time on any one pixel. As there isn't much information on this field the annotated image only points out the three Arp systems and the two asteroids.

Arp's image of #48
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp48.jpeg

Arp's image of #88
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp88.jpeg

Arp's image of #119
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp119.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME applies to all three.

Related Designations for ARP119

ARP120

Arp 120 is better known as The Eyes or NGC 4438 with NGC 4435 bottom to top. They are part of the Virgo Galaxy Cluster located some 60 million light-years away. Arp's classification of this one is under Elliptical and elliptical-like galaxies: Close to and perturbing spirals. The only problem is NGC 4435 is not perturbing NGC 4438 as Arp thought. It does have a large halo about it, the full extent not seen in my shot but it is very symmetrical and shows no hint of distortion. They have two very different redshift values. So different that if they did interact it was over almost before it started. So if NGC 4435 isn't the culprit who is? One possible answer I've seen is that NGC 4438 could be the result of a merger that's already happened and the debris hasn't as yet returned to the galaxy. The multiple planes of dust lanes near the core would argue for this, the fact only one core can be seen at all wavelengths would argue strongly against it, however. There things stood until last year. I missed it in fact. Glen Youman pointed out the correct solution to me. Seems the culprit is the big gorilla in the cluster -- M86! That's its glow coming in at the lower right. I cleaned up the image too much. I thought it had a gradient that was really hints of the connection to M86. I tried reprocessing but without H alpha data it just didn't work. For more information on this see: http://www.noao.edu/outreach/press/pr08/pr0807.html#images

The tidal cloud about NGC 4438 must be very thin however and contain little dust. Notice the reddish object in the darker triangular area north of the bright part of the galaxy. This isn't a foreground star but the distant galaxy SDSS J122746.38+130229.4 which is about 1.6 billion light-years distant. To be seen through the tidal plume at that great distance the plume must be very sparse and consist mostly of widely spaced stars with little dust and gas. Another galaxy is seen in the galaxy but may be in front of NGC 4438. It is the obvious elliptical just below the brightest part of the galaxy at the edge of the main halo and east of the tidal plume. It is VCC 1040 and has a blue shift so is moving toward us. It is classed as a dwarf elliptical and shows the wide variation of redshift to be found in this galaxy cluster.

Most class NGC 4435 as SB0 and NGC 4438 a mess. No two seem to agree. The NGC Project just says S... while NED says SA(s)0/a pec. NED says both are LINER galaxies. The two were discovered on April 8, 1784 by William Herschel. Both are in the original Herschel 400 program. My notes from April 20, 1985 taken on a fair-humid night at 50x read: NGC 4435 "Small, galaxy with a bright center. Somewhat elliptical. Forms a tight double with NGC 4438, 6 other galaxies seen in the same one degree field of view." NGC 4438 "Large, highly elongated galaxy with very large irregular halo that stretches nearly to NGC 4435. M 84, M 86 NGC 4402, NGC 4413, NGC 4425 and NGC 4435 are all in the same one degree field of view."

Then there's the rather peculiar galaxy to the northwest of Arp 120, the very blue IC 3355. SDSS gives it three separate numbers. A note at NED says;"Faint not disrupted progenitor. In its tail 3 diffuse companions in a blue haze." I can't find the third one, however. IC catalog considers it just one irregular Magellanic galaxy. It has a redshift similar to that of NGC 4435.

In the annotated image galaxies that are members of the cluster are identified by name but no distance is given as they are all about 60 billion light-years give or take 10 million or so. Exact distances are hard to determine since the velocities of member galaxies can vary greatly making red shift a poor distance indicator. Those with redshifts that put them far beyond the cluster are noted by their distance in billions of light-years. Several quasars out to past 11 billion light-years are noted. Some galaxies I can't determine any distance for but may or may not be cluster members are identified by name with a "?" to indicate this uncertainty. In all cases no redshift data was available. You will note that sometimes a cluster galaxy is right beside a distant galaxy but telling which is which without the labels could be difficult.

I took this data several years ago. Due to clouds I never did redo it as intended. Seeing was very poor and I was using a focuser that wasn't up to the job. The result is limiting magnitude is about 21.2 instead of my normal 22.5 and detail is a bit lacking due to 4" seeing. Maybe this spring I can redo it with a lot more data to get far more of the halos around both galaxies. Also, I pushed the color more than normal to bring out the subtle color differences in the plume. This caused IC 3355 to turn super blue. Indicating it has really massive star formation going on and may be more interesting than Arp 120.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp120.jpeg

14" LX200R @ f/10, L=8x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for ARP120

ARP121

Arp 121 is a pair of interacting galaxies in Cetus. Redshift data indicates rather rapid orbital motion which makes a distance estimate a bit fuzzy. I'll just say it is likely between 235 and 250 million light-years distant. The western galaxy is MCG -01-03-051, a Sa pec galaxy. The eastern one is MCG -01-03-052. I find no classification. Looks like an elliptical to me. It appears MCG -01-03-051 has had the worst of the encounter. There's a faint spray of stars between the two. I'm not sure to which galaxy they belong, most likely MCG -01-03-051. Arp classed it under Elliptical and elliptical-like galaxies: close to and perturbing spirals. His comment seems to just reiterate this; "Elliptical galaxy warping spiral." He is letting his images do the speaking it appears. There is a puff of something off the north end of MCG -01-03-051. I can't tell for sure if it is part of the galaxy or a different one. If a different one it isn't in any catalog that I found. This pair also would seem to fit under Arp's "Wind Effects" category as well.

The field is out of the SDSS area so again, I have little on this one or the field. Most galaxies in the field are found only in the anonymous Automated Plate Measurement United Kingdom Schmidt catalog with only position and magnitude with a hint of spectral data drawn from the differences seen in the red and blue survey plates.

I find distance data on only 4 galaxies besides the two in Arp 121. All are in the lower left corner and is a group of galaxies in which 4 have a known redshift.

The main galaxy down there is the nice spiral that looks somewhat distorted, maybe by the anonymous galaxy superimposed on its southeastern edge. It is MCG -01-03-054 Arp has a whole class of "Spiral Galaxies with Companions on Arms". Somehow he missed this one or decided he already had enough of that class. The tight group to its upper left is known as the MCG -01-03-054a group. PGC 3596 galaxy is also known as MCG -01-03-054a, hence the name. Its distance is listed as a bit more as MCG -01-03-054.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp121.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP121

ARP122

ARP 122 falls in his category for elliptical and elliptical-like galaxies close to and perturbing spirals. The spiral, in this case, is NGC 6040 and the elliptical NGC 6040B. Oddly Arp's paper incorrectly calls Arp 122 NGC 6039. Everyone classifies NGC 6040 as SAB(s)c. Arp's comment on this one only reads: "E galaxy warping spiral." Certainly, it is warped. Quite likely, in this case, they are interacting but it could be it was warped by something else as this is a dense cluster with many interactions over its lifetime. It was discovered by Édouard Stephan on June 27, 1870.

This data was taken September 13, 2007. I didn't have the tools to do it justice back then. I need to reshoot this one. It also contains ARP 71, Arp 172 and Arp 272. Details are in the annotated image. The annotated image shows details on many other galaxies in the cluster and beyond it.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp122.jpeg

14" LX200R @ f/10, L=6x10' RGB=3x10', STL-11000XM, Paramount ME

Related Designations for ARP122

ARP123

Arp 123 is in the Arp class "Elliptical or elliptical-like galaxies; close to and perturbing spirals". In this case, the spiral is NGC 1888 and the elliptical is NGC 1889. At first look, there doesn't appear to be much distortion. Usually, we expect to see the distortion on the side of the companion but that doesn't have to be the case. Here it is on the opposite side and takes the form of a large, faint blue halo of new massive blue stars. I looked at several papers on this pair but none were concerned with how the interaction would only throw out mostly new hot blue stars leaving the old population of stars mostly unchanged. Was there a lot of gas in this area and the interaction triggered the star formation? If so why aren't they in clusters? There's no sign of dust, just the stars. I found it odd that no one was much interested in this. Maybe it isn't a puzzle to them but it sure is to me. The pair is about 115 million light-years away.

The papers did have this to say: "Liu & Kennicutt (1995) state NGC 1888 to be a spiral of the type Sa or Sb with dominant old stellar population and only weak line emission." Yet another paper says; "With NGC 1888, forms = Arp 123 an interacting pair at 0.3 arcmin, consisting of a large Sc with faint outer arms and a small E0 in contact." I doubt that means actual contact, just apparent contact. I see no evidence of an actual collision.

The other galaxy of any size is toward the upper left corner, northeast of Arp 123. It is MCG -02-14-015 a flat galaxy (FGC 0534) also at 115 million light years. With the same distance, it must also be a very close neighbor to Arp 123. NED classes it as S0 which seems strange for a flat galaxy though it does have a central bulge most flat galaxies lack. Those are usually white to yellow, often elongated spindle-shaped galaxies with little to no dust or gas and consisting of old stars indicating star formation ceased billions of years ago. Yet this galaxy has the typical blue arms of an edge on spiral. On the other hand, it has no dust lane as you'd expect with an S0 galaxy. One paper I found says it is "an anonymous Sc galaxy" in a paper on Arp 123. Only a very few other galaxies have been cataloged in this image. They are strong emitters of IR radiation and thus in the 2MASS catalog of IR sources. No visual or redshift data is available on them, however.

This galaxy pair is located in Lepus the rabbit, near the border with Orion. Down that low, my seeing is never very good though was somewhat better than average for its declination. Still, the image is not what I would like. NGC 1888 was discovered by William Herschel on January 31, 1785 but isn't in either of the Herschel 400 observing programs. He didn't see NGC 1889 as a separate object so its discovery didn't happen until Bindon Stoney recorded it on October 29, 1851.

Arp's image is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp123.jpeg

It appears his seeing wasn't much better than mine. Though the poor dynamic range of film caused him to lose a lot of detail in the galaxies while exposing long enough to pick up the blue halo. Today's digital sensors don't have this limitation. Though I again put a bright star on the edge of the chip. Difficult if you try but apparently very easy to do if you don't.

14" LX200R @ f/10, L=6x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP123

ARP124

Arp 124 is a pair of galaxies located just north of the head of Draco at a distance of about 175 million light years. It consists of a spiral classed as SAb or Sab? and is seen nearly edge-on. The companion is an elliptical or S0 galaxy at about the same redshift. Arp classed them under Elliptical and elliptical-like galaxies close to and perturbing spirals. In this case look at the dust lane. It looks a bit like the integral sign ~ as it follows the warping of the spiral galaxy's disk I really don't see it in Arp's overexposed image. Though the upturn of the disk near the companion is quite evident. The spiral is NGC 6361 while the companion is CGCG 300-007. Arp had no comment on this one. NGC 6361 was discovered on August 18, 1886 by Lewis Swift.

When I consulted NED about galaxies within 15 minutes of Arp 124 I expected it to return about 2000, that's pretty much the norm for a field covered by the Sloan survey. My field is a bit over 15 minutes in radius in RA, slightly less in declination. So it's safe to say the number seen in this circle is the minimum in the image. This time it returned a nice round 10,000! Most, however, are deep red in color and faint. My CCD is very insensitive in red so can't go all that deep in that color. Thus only a few hundred of these actually show in the image. There must be a lot of reddening dust along this line of sight. There, though is a small group of red galaxies I was able to pick up down and right of Arp 124. The bright core galaxy of the group is magnitude 18.8 in green light so easily within my range. The galaxy is SDSS J171804.77+603342.3 and is listed as an IR source in the 2MASX survey. It is about 2.85 billion light-years away light travel time. I assume those around it are too but there's no redshift data on them I could find.

This is a good time to mention the problem of what is an object's distance. This isn't a simply answered question when the object is rather far away like this red galaxy is. It is likely about 3.2 billion light-years from us now, if that has any meaning in a relative universe and was 2.5 billion light-years away when the light left it. Now we have three distances. All very confusing. In our everyday life, we assume light travels instantly and the distance to an object is easily determined. But when it takes billions of years for light from an object to reach us in an expanding universe things get very complicated. The universe can change greatly while the light is in transit to us and for very distant objects is much bigger than it was when the light started its journey. So is the "right" distance the distance it was billions of years ago when the light left, the distance the light traveled to reach us, the distance it is "now" considering how much the universe expanded over those billions of years or is it something else? Normally for these posts, unless I say otherwise, I'm using light travel time which is just a measure of how long ago the light left the galaxy and thus how far it traveled to reach us. For objects like Arp 124 that are "close" by the three are about the same so the issue is moot. But when considering more distant objects like GALEX 2543762069798264999 below things get more "interesting."

There's a low luminosity galaxy that looks rather odd in the upper left corner of the image. It is SDSS J172029.73+604442.5 and is about 165 million light-years distant. That's close enough to the distance to Arp 124 to indicate they are likely part of the same galaxy group. Out of the 10,000 objects, NED found not one was a quasar. But this last galaxy is a bit beyond that circle and in checking it out I found a quasar near it that was just beyond my 15 minute radius. It is directly west of the low surface brightness galaxy about 1.5 minutes and appears as a faint blue star. In fact, it is an ultraviolet source recorded by the GALEX UV satellite. Its catalog entry is GALEX 2543762069798264999. At magnitude 18.9 in green light, it is 6.6 billion light-years distant, light travel time. Keeping in mine our distance discussion its distance at the time the photons I recorded left it was 5.0 billion light-years while its distance "now" is 8.7 billion light-years. Notice how the distance problem gets greater the more distant an object is. When dealing with objects with very high redshifts this gets much worse very rapidly. For instance, if stars had existed a few seconds after the creation of the universe 13.7 billion years ago we measure its light travel time at 13.7 billion light years yet it would have been only a light year or so from us if our galaxy existed then. That's a real mind blower. Of course, no stars or galaxies existed then or for millions of years so that paradox doesn't occur. When you do all the math you find that today's universe is at least 100 billion light-years across and we can see back nearly to its beginning over 13 billion years ago we can only see a sphere about 27 billion light-years across. The rest of the universe will never be seen, in fact, the visible portion will become an ever decreasing percentage of the total universe. Look now while you can. All this gives me a headache.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp124.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP124