ARP083

Arp 83/NGC 3799-3800 is found near Denebola in the tail end of Leo, about 170 million light-years distant. Arp put it in his class of spiral galaxies with large, high surface brightness companions on arms. Again, what he sees as an arm is more a plume due to interacting galaxies than a real arm. Arp seems to recognize this in his comment: "Some hazy material at juncture of two arm; high surface brightness, S shape inside comp." Radio data confirms these are interacting galaxies in a common HI halo. NGC 3799 is the small companion, NGC 3800 the large spiral with the odd arm structure of one major drawn out arm and a chaotic mess for the other one. Oddly both seem to start out going northeast. There's a third member of this interacting group, NGC 3800A to the northeast. Oddly a note at NED says it isn't recognized by NED, whatever that means.

NGC 3800 is classed at NED and by Seligman as SAB(rs)b: pec while the NGC project seems to throw up its hands just saying S... NGC 3799 is classed as SB(s)b: pec at NED with Seligman agreeing and again, S.. at the NGC Project. Both galaxies have exactly the same redshift of 3312 km/s though NED notes one source says NGC 3800 has a much different redshift of 5852 km/sec putting it over 100 million light-years further away. This seems unlikely. NGC 3800A has a nearly identical redshift, 3300 km/s and radio images show a warped HI disk indicative of interaction with the other two.

NGC 3800 was discovered by William Herschel on April 8, 1784 but isn't in either of the Herschel 400 observing programs. NGC 3799 was discovered by his son John Herschel on April 21, 1785.

North and a bit west of Arp 83 is a blue object that the Sloan survey shows both as a galaxy and quasar. The quasar's position being 0.01" of RA further east than the star. Both are shown as 0.09" in size which is to say star-like. I've shown it as G/Q in the annotated image. If a quasar it is one of the closest ones though at magnitude 19.1 likely too faint to be seen visually. Just north of it is another blue starlike object. It is only slightly closer (but same distance given the error bar of measurements like these) and is shown only as a galaxy.

An X-ray bright galaxy cluster discovered by the ROSAT X-ray observatory -- now deceased -- is centered on the location of a BL Lac galaxy/quasar again depending on what catalog you believe. There's little information on the cluster RBS 1015. The galaxy is an IR source in the 2MASS survey, A BL Lac galaxy in the Sloan survey and quasar in the BZB and [MGL2009] catalogs. The latter two while listed in NED as the catalogs seeing it as a quasar, are undefined catalogs in NED. When asked to do so NED responds that isn't a valid NED designation, yet they use it. ARGH! BL Lac objects are another type of AGN in which the active jet is likely pointed nearly directly at us but feeding far more slowly than a quasar's black hole. Google the term for more information.

In the lower left corner right at the bottom edge is the galaxy cluster, MaxBCG J175.27433+15.14893 with a photographic redshift distance of 2.8 billion light-years. The galaxy at its center is SDSS J114105.83+150856.2 with no redshift listed but the same position within a fraction of a second of arc. The cluster is said to have 21 members but no size was given. So I marked it as GC/G with a question mark for the galaxy's distance.

The bright stars in the image are somewhat distorted due to tube currents caused by severely dropping temperatures this night. My notes indicate a 10C (18F) degree drop in the 1:43 time needed for this image. This also caused a rather large shift in image scale with the last images being 0.0025" larger per pixel. This might not sound like much but across 2004 pixels that is a 5 pixel difference! Fortunately this is something Registar handles easily. The temperature drop ruined seeing as well so the image is rather fuzzy overall. Another for the proverbial reshoot list.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp83.jpeg

Sloan image
http://astronomerica.awardspace.com/SDSS-28/NGC3800.php

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

Related Designations for ARP083

ARP084

This is Arp 84/NGC 5394-5. Arp 263 looks like a loon. This one looks like a blue heron eating a fish. Both are commonly seen on the lake I live on. Herons however make a nasty mess on my dock! The body is NGC 5395, the neck and head NGC 5394 and the "fish" in its beak is SDSS J123826.24+372708.7. Blue herons have a crest that normally lays back across the head and down the neck. Even that shows in this galaxy trio. Actually, the fish is unrelated to the other two and is not part of the Arp designation. The two galaxies making up the blue heron are a bit over 160 million light-years from us while the fish is a bit over 650 million light-years away. Heron's may have a long bill but not that long! Arp classifies this one under "galaxies with bright companions". The interaction has really drawn out the spiral arms of NGC 5394 to make the neck and head. While arms have been ripped off of NGC 5395 helping to shape the body. Notice how the blue arm connecting to the "neck" shows no connection to the rest of NGC 5395 and in fact seems to get wider when it should get narrower. Also, the arm at the top going to the left comes out of nowhere and again isn't connected to the galaxy. Obviously, a lot of interaction is going on here. Both were discovered by William Herschel on May 16, 1787 but aren't in either of the Herschel 400 observing programs.

The odd blue galaxy at the far left is MAPS-NGP O_271_0033361 but I can find no distance data. To the right of the fish is a red star. below it is a small starlike galaxy. That one is 1.8 billion light-years away. Near the lower right corner are 4 galaxies. The two upper ones rather elongated the lower ones round, all are slightly to strongly orange. They are all about 770 million light-years away though I found no listing as a galaxy group for them. Nearby to the upper right is a small blue galaxy that is 1.1 billion light-years away.

The bright orange elliptical above and a bit left of the "bird" is IC 4356 and about the same distance from us as the "fish". It may be part of its galaxy group. The other galaxy to its right is an unknown. To the immediate left of NGC 5395 is a small bright blue galaxy. It too is located at the same distance as the fish so may also be part of its group.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp84.jpeg

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

Related Designations for ARP084

ARP085

Arp 85 is better known as M51, the Whirlpool Galaxy. It is probably the easiest to see as a spiral in an amateur size telescope. Arp put it in his category for Spirals with large, high surface brightness companions. This time the companion is really a companion and they are interacting. Being well studied we know that the larger galaxy, NGC 5194 has passed slightly in front of the smaller, NGC 5195. The interaction has drawn out an arm from NGC 5194 whose dust lanes are seen against NGC 5495 making this smaller galaxy look even stranger than it really is and giving it a red color due to being seen through the dust. NED classifies NGC 5194 as SA(s)bc pec; HII Sy2.5. Seligman agrees though ads a question mark. The NGC project says more simply Sc. NED classifies NGC 5195 as SB01 pec as does Seligman. The NGC Project, however, says SB0-a. Red-shift puts the pair about 30 million light-years distant. NGC 5194 was first seen by Charles Messier on October 13, 1773. The companion wasn't seen as a separate galaxy until March 21, 1781 when Messier's friend Pierre Méchain recorded it.

I took this image 5 days after supernova 2011dh was discovered. The delay was due to lousy weather. Even then clouds prevented but one 10 minute round of color data rather than my normal 2. I did add in H alpha data from a previous image to help bring out the HII regions in the system. The SN was still brightening as a type IIP SN when I imaged it. I got a magnitude of 14.4 and the following night through clouds I measured it at 14.0. Clouds returned until it had faded below this level. The P indicates it is a plateau type SN that after a short fall, levels off for a bit before continuing to fade. Thanks to clouds I missed that phase.

There are two IC galaxies in the image, IC 4277 and 4278. I have no distance data for IC 4277 unfortunately. Seligman says S?? It looked flat enough to be in one of the flat galaxy catalogs but I didn't find it in any of them. IC 4278 is a strange galaxy some have said is either a double nucleus or interacting pair. The Sloan survey image, however, shows the two blue blobs to be connected by a slightly red bar pretty much ruling out either of these ideas. Seligman classifies it as Ir??. I'd add a B for the bar. Both were discovered by James Edward Keeler on May 10, 1899. He was using the Crossley reflector at Lick Observatory to image M51 and picked up 7 IC galaxies, including these two in the image. Another he found that night is IC 4282. Seligman classifies it as dE??. Keeler was director of the observatory at the time. He died the following year at the age of 42. His ashes are interred in a crypt at the base of the 31 inch Keeler Memorial telescope at Allegheny Observatory.

The annotated image has information on other galaxies in the field.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp85.jpeg

14" LX200R @ f/10, L=4x10' HA=3x30' RGB=1x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP085

ARP086

Arp 86 is a pair of interacting galaxies in Pegasus, just north of the Great Square. It is about 220 million light years distant. To appear this large at that distance means it is a very large spiral galaxy. 225,000 light-years across including plumes. Arp put it in his class; "Spiral Galaxies with Companions on Arms: Large High Surface Brightness Companions. The companion certainly has a high surface brightness. I had to process it separately to prevent it from burning in as I stretched the image.

Arp's comment on this entry was: "Double arm leading to companion." This shows better in his image than mine. Probably due to his blue emulsion picking out new, massive stars that define arms and ignores older, smaller stars as shown by how dimly he picked up the core of the galaxy which is quite red and the seeing atop Palomar mountain being better than I have atop my little hill above the lake. Where are those laminar air flow mountains when you need them in this state?

The big spiral is NGC 7753 which is classed as SAB(rs)bc. The companion is NGC 7752 which is classed is I0? with strong HII emission lines. It seems to contain three main clumps arranged randomly. Notes at NED can't agree on it. One says; "This is a blue galaxy as indicated by the color profiles." But another says; "Compact elliptical red object which, with the spiral galaxy NGC 7753, constitutes a M51-type system." So is it red or blue? It is rather white in my image with some hint of red at the west end. I'm wondering if the HII emission features are causing this discrepancy. Another avoids the issue saying; "Very small and bright. Peculiar." No one would argue that. To my eye, the tidal arm from 7753 passes behind 7752 but isn't seen on the other side.

NGC 7752 was discovered by R. J. Mitchell on November 22, 1854. NGC 7753 was discovered by William Herschel on September 12, 1784. It isn't in either of the Herschel 400 observing programs.

The rest of the field is little studied. The Sloan survey didn't include this area of the sky. A few distant red galaxies are in the field. Most are found in the 2MASS survey but without any distance data. The small elliptical below NGC 7753 is 2MASX J23470758+2926531. I find nothing on it or any other galaxy in the image.

The field appears noisy. At first, I thought I'd done something very wrong in my processing or else there were thick clouds in the area I didn't know were around. But after deeply stretching the POSS II plates I saw this was due to the Integrated Flux Nebula being weakly in the field. I found few images of this one on the net and none, not even one by Adam Block then at Kitt Peak show it that I found. If I'd have realized it was there I'd have put more time into it to better bring out the IFN. There's always next time.

I've included a 1.5x enlarged cropped version as well as the full image at native image scale of 1" per pixel.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp86.jpeg

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

Related Designations for ARP086

ARP087

Arp 87 is a pair of galaxies in northeast Leo about 335 to 340 million light-years away. Arp put it in this category of spirals with large high surface brightness companions on arms." His comment is more telling. It reads "Arm appears wrapped around cylindrical companion." His was a pure descriptive narrative. He left it to others to explain what was going on. In this case, we have a pretty good idea and it's quite interesting. This appears to be the formation of a polar ring galaxy caught in the act of formation. The companion is well underway of becoming a polar ring galaxy.

The two galaxies are known as NGC 3808A and B. B is the "companion." NED classes A as SAB(rs)c: pec and B as I0? pec. NGC 3808 was discovered by William Herschel on April 10, 1785. It isn't in either of the Herschel 400 observing programs.

A note at NED references an article about the strange velocity distribution of the companion galaxy's disk and forming a ring is at: http://adsabs.harvard.edu/cgi-bin/bib_query?1994A%26A...291...57R A summary at NED reads: "The gas radial velocities on the major axis of the galaxy give evidence of very peculiar kinematics: photometric and kinematic centers differ by about 0.3 kpc. Rotational velocities after the global maximum at r~3" (1.4 kpc) show a rapid decrease to zero velocity (!). The rotation curve of the forming polar ring represents almost a straight line ({sigma} = 9.3 km/s) with a gradient of 12.9 km/s/arcsec (28.7 km/s/kpc). The crude estimation of mass to B-luminosity ratio is 3 f_sun_."

This one has attracted the interest of enough astronomers that the HST was used to study it. The resulting image is at http://dic.academic.ru/pictures/wiki/files/65/Arp87full.jpg
This really shows the ring being wrapped around the galaxy quite clearly. Though to my eye, it seems to change the direction of its rotation. I can't quite wrap my mind around it.

Just beyond the "companion" is a nice near edge on spiral that shows a lot of detail in the Hubble image. I couldn't find any redshift data on it. In fact, I couldn't find it! NED has the faint 22.3 magnitude star just of the tip but not the galaxy itself. It's amazing what gets left out of these databases. Dennis Webb did a lot of work identifying galaxies in Arp fields but he couldn't find this one either. He does though draw a diagram of how the arm wraps around the companion. I can't quite see it however as mentioned above.

To the lower right of Arp 87 is a candidate galaxy cluster at about 1.5 billion light years. NED has no data on its size or galaxy count. Many possible galaxies are in the area of the label however which is centered over the location. It reads "GC 1.5". The candidate cluster is NSC J114001+221959.

Toward the upper left corner of my image is an interesting double galaxy. The lower one is a spiral, SDSS J114132.58+223351.3, at 1.1 billion light years. It has a possible companion on its northern arm, SDSS J114132.48+223402.8 distance unknown. So I can't verify if they are interacting or just line of sight.

Below and further left of these two is an obvious pair of spirals that do both have redshift distance and they are virtually identical at 1.2 billion light years. Though I see no hint of interaction as I may be seeing with the previous two. Between these two pairs is what may appear to be yet another pair but the rightmost object is just a foreground star in our galaxy. The distance to the galaxy is unknown.

A lot of galaxies I'd like to know the distance of, have yet to be measured. In the lower left corner, for instance, are several galaxies of about the same angular size and brightness. The two with known distances are widely separated, however. What about the others. Could the blue near and redder twice as distant? Color can be a good distance indicator but it can be a great way to go wrong with confidence as well.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp87.jpeg

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

Related Designations for ARP087

ARP088

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 ARP088

ARP089

Arp 89 also known as NGC 2648 and KPG 168, is classed by Arp under spiral galaxy with large, high surface brightness companion. The main galaxy is also cataloged as NGC 2648 with the companion being CGCG 060-036/PGC 24469. The KPG designation though is for both and stand for "Karachentsev Isolated Pairs of Galaxies Catalogue". These two sure are isolated. Nothing but faint distant galaxies with little available data are in my 1" per pixel image. The main galaxy is classed as a Sb spiral by NED but the NGC Project and Seligman say Sa. Usually you'd see such a galaxy as having rather blue arms. In this case it is rather uniformly the reddish yellow color of most S0 galaxies. One paper even remarked on its completely flat color profile. Until I read that I was wondering about my processing, I just couldn't eke out any blue in the arms no matter what I did. NGC 2648 was discovered by William Herschel on March 19, 1784 but isn't in either Herschel 400 observing program.

The companion, classed as Sc by NED and S? pec by Seligman, however, looks like a typical interacting spiral with nice vivid blue arms indicating new star formation is going on there. It also shows some tidal distortion with blue stars ripped from its arms. The main galaxy seems totally immune to the interaction with no new stars and no distortions. Odd. Both are about 107 million light-years away so are likely really interacting. They are found in the constellation of Lynx.

Arp's photo of this pair with the 200" telescope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp89.jpeg

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

Related Designations for ARP089

ARP090

Arp 90/NGC 5929-30 is an interacting pair of galaxies about 120 million light-years away in the constellation of Bootes. Arp put it in his classification for spirals with high surface brightness companions on the arms. He recorded this comment: "Absorption lanes around companion." This pair should be visible in an 8" telescope for those going after these visually. It was discovered by William Herschel in 1828 using an 18.7" speculum mirrored reflector. At least NGC 5930 was or maybe he saw both as one object. It isn't in either Herschel 400 observing program.

NGC 5929, on the right, is classed as Sab Pec and is a Seyfert 2 galaxy. It was discovered on May 13, 1828 by John Herschel. NGC 5930, on the left, is classed as SAB(rs)b pec at NED and SBb/P by the NGC project. Several notes at NED say 5930 has a starburst nucleus though this isn't mentioned in the classification at NED. Both the Seyfert 2 status of NGC 5930 and the starburst core of NGC 5930 can be an indication of interaction though either can occur without it. Here it appears interaction is involved.

"Behind" Arp 90 off its lower left side is a small blue blob. Is it a plume or a separate galaxy. It appears to be a low surface brightness galaxy in my and the SDSS image but NED shows nothing at this position. Thus it is marked with a question mark on the annotated image.

To the northeast of Arp 90 is UGC 09857 at 110 million light-years by redshift. This difference is rather insignificant and can easily represent the relative motion of related galaxies. It is classed as IBm. Is it naturally irregular or has it had a nasty encounter with Arp 90? I found nothing on it either way. It sure is interesting looking. Wish we could see these from a closer vantage point.

The annotated image shows some interesting things. Arp was a strong believer that quasars aren't distant massive black holes on a feeding frenzy in distant galaxies but are nearby objects ejected from galaxies. This puts him in the near crackpot category of many astronomers. His theory goes that as time passes their redshift increases. Why requires rewriting physics. Read the Kanipe-Webb book on the Arp Atlas for the details. He cites several galaxies in which the redshift of the quasars in the field increases with angular distance from the galaxy. That appears to be the case here. The one nearest Arp 90 has the lowest redshift value (converts to distance as 6.2 billion light-years) increasing (using today's accepted distance conversion of redshift) to 8.1, 10.5 and finally 11.3 billion light years. One minor hitch is one to the east that's even further from Arp 90 but is only 9.2 billion light years distant. Of course, Arp says those distances are false as all are about the same distance as Arp 90. The odd one is explained that the ones with higher redshift are really further from Arp 90 but only appear closer when projected onto a 2 dimensional image plane. Of course, by that logic, nearly any distance could be supported. You could just as easily say the one at 6.2 is really the furthest as it is was ejected away or toward us and thus the distance we see is greatly foreshortened. From what I read in Kanipe and Webb's book this didn't seem a problem to Arp.

In any case, after several fields without any quasars, there are at least 7 in this image ranging out past 11 billion light-years by established redshift theory.

There are a lot of galaxies, many fall into two very precise distance measurements. One set at 1.0 billion light-years and another nearly twice that at 1.9 billion light-years. The latter pretty much covers the entire field. Also noted in the annotated image is the center position of the galaxy cluster Abell 2080. It is listed as 30 minutes in diameter. It would extend from its position near the eastern edge of my image to the middle of the image. That doesn't fit the distribution of either of the two distance groups in my image. The catalog gives little other help just saying it is "distant class" 6. All that means is the 10th brightest member has a magnitude between 17.3 and 18.0. Most of both the 1 and 1.9 billion light-year groups fit that range but extend beyond the 30 minute diameter. So which galaxies in the image are part of the group? I have no idea.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp90.jpeg

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

Related Designations for ARP090

ARP091

Arp 91/NGC 5953-4 is a well-studied pair of interacting galaxies in Serpens Caput about 100 million light-years distant. Arp put them in his category for Spiral galaxies with high surface brightness companions on arms. He made the comment: "Broad peculiar arm to companion, then absorption; faint extension from companion." This appears to refer to the odd band of stars coming from the south end of NGC 5954 (left) and going to NGC 5953 but suddenly appearing to be cut off. I have to wonder if NGC 5953 is slightly in the foreground and its dust suddenly blocks the light from this star stream. In the SDSS image, it may be faintly seen reappearing after passing behind the densest part of NGC 5953. The SDSS image with its three IR channels shows very reddened dust or maybe population 1 stars right where the stream appears to end. I didn't see this color in my image. Unfortunately, seeing was 3.5" when I took my image so it is pretty fuzzy and low resolution. It is on my reshoot list if the weather will ever cooperate. The last part of Arp's comment likely refers to the huge tidal cloud of stars about NGC 5953. I assume 5953 is the "companion" and the funny star stream the "arm" it is on.

I find references to NGC 5953 calling it an elliptical appearing galaxy, an S0 galaxy and very recent references saying it is SAa: pec;LINER;Sy2. Usually, a galaxy is either LINER or Seyfert 2, but this has references saying one or the other. One trying to make sense out of this says spectra from each camp is very different with many lines having very different strengths in various spectra leading to this differing classification. In any case, the HST put an end to the debate on its status as elliptical S0 or spiral. It's high-resolution image clearly shows it to be a flocculent spiral. I'd hoped to see some resolution of this but only one rather bright flocculent cloud on the east side shows in my image. It also is the only one to show in the Sloan survey image which is far sharper than mine. So apparently this detail is below my resolution ability even on a good night. Still, I want to try again for it. Arp's image does show hints of the flocculent arms which is why I'd hoped to catch a hint of them. Unfortunately, the only HST images I could find don't include the strange star stream talked about above. Apparently, it wasn't of interest to whoever requested the data be taken.

NGC 5954 has no major tidal cloud about it, just the stream appearing to head toward NGC 5953. But it certainly is highly distorted. It has several prominent star clouds that are nearly starlike in my image as well as the Sloan image. But they are very blue in the Sloan image while in mine only the northern one is blue. The others are severely reddened. I can't explain the difference other than the Sloan image goes into the UV spectrum. That may be contributing to their blue color. Or maybe it was just my lousy seeing which was even worse for color data, especially the red channel. Another reason to reshoot this one. It is classed as SAB(rs)cd: pec Sy2. The core region is elongated in the HST image. Maybe that's why it gets a nod to being a barred spiral. I just say it's a really messed up spiral.

Both galaxies have intense star formation going on near their cores, likely fed by their interaction. To me, the spiral structure of NGC 5953 is not all that disturbed while that of NGC 5954 is a total mess. This makes me think many of the stars in the cloud about NGC 5953 came from NGC 5954. While it appears the larger and is obviously the spiral in Arp's classification the lack of distortion to the core of 5953 makes it more the main spiral with 5954 the "companion". It must, at least, have a very dense core region to withstand the tidal effects of their interaction. Something NGC 5954 couldn't seem to resist very effectively. Both were discovered by William Herschel on April 17, 1784. Neither are in either Herschel 400 observing program.

Below this pair is very blue galaxy UGC 09902, a SBdm? spiral. While redshift data puts it quite a bit closer the error bar for its true distance certainly makes it possible it is part of the same group as Arp 91 though this isn't necessarily the case. In any case, it is an interesting low surface brightness galaxy in its own right.

In the lower right corner is NGC 5951. When I set up the image I didn't realize it was there or at least that it was interesting. Thus it ended up cut off. Yet another reason to reshoot this field. It is classed as SBc:. It has a rather odd dark lane that runs off the image. Its redshift puts it about 88 million light-years away. Like UGC 09902 it may or may not be part of the same group as Arp 91. I don't really see it as a barred spiral but it is so tilted to our line of sight that may be hidden in my low resolution. I'd sure like to see it more face on.

NED shows no redshift data for anything else in my image so I've not prepared an annotated image.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp91.jpeg

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

Related Designations for ARP091

ARP092

Arp 92 falls under Arp's class: Spiral galaxies with companions on arms: Elliptical galaxy companions. If by "companion" Arp includes unrelated line of sight galaxies then this might be true. In this case red shift data, possibly not known when Arp prepared his catalog, shows the main galaxy, NGC 7603 has a light travel time distance of 385 million light years while the "companion", NGC 7603B is at a distance of 728 million light years, nearly twice as far away. So it isn't the cause of the distortion and tidal plume coming from NGC 7603. Or is it, NED lists a couple papers that do consider it a true companion even acknowledging the red shift difference. Arp comments: "Very faint connection shows better in red." Indicating he sees this plume as a true linkage. In later years Arp denied red shift necessarily indicated distance though at the time of the catalog he hadn't come to this belief. It is classed as SA(rs)b: pec and is a Seyfert galaxy. So is it a companion or not? I'll say no until better evidence is provided. NGC 7603 was discovered by Albert Marth on October 23, 1864.

With time the "guilty" galaxy might be some distance away. There are two candidates I find in the image. NGC 7589 to the west (right) is the odd spiral with faint narrow arms. It has a redshift almost identical to that of NGC 7603 that puts it at 389 million light years. It is classed as SAB(rs)a: and is a Seyfert 1 galaxy. So it is the most likely candidate for the true "companion". Though in the upper left corner is another possible mugger. It is odd rather "sloshed" streak of a galaxy known as ASK 025830.0/SDSS J231929.76+002212.0 at a redshift that puts it a bit further away at 407 million light years. Sometimes an interaction will move the core of a galaxy from the center and toward the galaxy it interacted with. Could that explain this galaxy? All this is speculation on my part. Too bad we can't rewind time and see what this system looked like a billion years ago. To me, a more likely cause is a merger. The plumes caused by a merger in the past.

Adding to the confusion is that the galaxy Arp considered the companion, NGC 7603B is also a Seyfert 1 galaxy. Probably just a coincidence. Some galaxies just have an active core. That could be the case here.

There happened to be three asteroids in this image. The one below Arp 92 is (123944) 2001 EU20 at an estimated 18.5 magnitude. The one to the northwest corner is (218053) 2002 DT1 at an estimated 18.4 magnitude. Yet it is obviously dimmer in my image. Though this may be an illusion due to its more rapid motion. The third is in the lower right corner and is (66172) 1998 VX45 at an estimated magnitude of 18.0.

West of Arp 92 beyond and a bit below NGC 7589 is an odd, apparently double, very blue, galaxy. As I've mentioned many times before these are often excluded from the SDSS catalog as listed in NED. This is another example. It was picked up by the automatic plate survey so is listed under it as APMUKS(BJ) B231533.01-000313.1 It also made LEDA as LEDA 135885 but not Sloan. But NED makes the odd classification as Sb or plate flaw! Then to make this more ridiculous they calculate a redshift distance of 377 million light years for this possible plate flaw. It is yet another strange galaxy that is part of the group with Arp 92. So is it a double galaxy or one with a plume or what is it? Is it involved with Arp 92? Note that in my image the upper half is a bit bluer than the lower half. Also, NED classified it as either Sb or a plate defect. Apparently, some things don't change when new information is available. You can't get a distance estimate from a plate defect by any means I'm aware of. Things just get curiouser and curiouser as Alice would say.

There are quite a few galaxies right at the limit of this image. They are about 22nd magnitude and about 5.1 billion light-years away. At least a few are of this same distance. I've prepared an annotated image with galaxy and quasar distances labeled in billions of light years. As usual, the label is just right of the object unless this isn't possible without hiding something. You may need to enlarge the image to see some of these little faint guys. My limiting magnitude here was about 22.4 in green light. NED lists some 5000 galaxies in this image with a redshift value. The annotated image only shows a few that interested me.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp92.jpeg

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

Related Designations for ARP092