NGC4753

Who scribbled on my galaxy?

Every time I think I've seen the ultimate strange galaxy a new one to top it turns up. This one has the record for now. I knew it had a few strange dust lanes but when so many popped out in the processing I was muttering words not suitable for this post. My mind does strange things when confronted with something unexpected. All I could imagine was God gave baby Jesus a crayon and paper to draw on and he scribbled on the galaxy instead of the paper. Coming back to some sanity it is obvious this is a merger situation. Stars thrown all over the place and dust lanes apparently scattered at random. One paper, however, has tried to make sense of it all and claims to have succeeded. It says the dust comes from a warped disk tilted at 15 degrees and twisted by differential precession. I'm not sure he can fit all this dust into his model but some does seem to match. You can read all about it at: http://cdsads.u-strasbg.fr/cgi-bin/nph-data_query?bibcode=1992AJ....104.1339S&link_type=ARTICLE&db_key=AST&high=

This is a member of the Virgo Cluster located about 60 million light-years away by Tully Fisher measurements. Its large angular size makes it an easy target for imagers yet it is ignored by virtually all who seem stuck in the rut of imaging the same stuff. The galaxy is in central Virgo less than three degrees east of the double star Porrima. It was discovered by William Herschel on April 12, 1784 and is on the original Herschel 400 observing list. My entry for it on April 23, 1985 at 50 power with my 10" f/5 under a light ground fog says: "Large, oval galaxy with a somewhat brighter but small (not starlike) nucleus." Most consider the nucleus starlike. Conditions likely caused me to miss it and it appears I never went back to look at it visually again for some reason.

With a lot more exposure time than my 40 minutes of luminance it should bring out much more of the diffuse plumes surrounding the galaxy. More time likely would allow the dust to be traced further from the core as well. I needed the high signal to noise ratio of the core region to bring out these dust lanes. I had to reduce my efforts to pull these out the further I got from the core as the lowered signal to noise ratio wouldn't support the severe processing needed to bring these out.

As usual, I've noted all objects with a redshift distance in NED. UvES objects are all quasar candidates with less precise photographic redshift determinations "p" after the look back time. Two faint and one somewhat brighter asteroids are in the image. Their magnitudes are estimates by the Minor Planet Center and don't appear all that accurate, at least in the case of (147658) 2004 JP41 which seems much fainter than its prediction. Otherwise, I didn't notice anything particularly noteworthy about these background galaxies.

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

Related Designations for NGC4753

NGC4762

NGC 4762 and NGC 4754 are said to be a pair of non-interacting galaxies. NGC 4762 is a rather odd galaxy seen exactly edge on. A bright star-like core is seen with a very narrow disk oddly missing any hint of a dust lane. This leads to it being classed as SB0? by the NGC project and SB(r)0^0^ at NED. The disk ends with a huge warped plume off each end. The south end curves sharply to the west but a faint plume continues southwest and another to the southeast. Off the northeast end of the upper plume, a narrow faint plume continues to the northeast. To have these various plumes it must have interacted with some other galaxy in the last billion years or so. Redshift puts its distance at about 60 million light-years. Unfortunately, the error bar is rather large at this range. Tully Fisher measurements show 55 million light-years while an analysis of its globular cluster's brightness put it at 78 million light-years. Pick one!

The companion is NGC 4754 which is also unusual as the outer oval is oriented about 45 degrees counterclockwise from the inner oval and bar. Again, this would seem to require an interaction with another galaxy. NED classes it as SB(r)0-: and the NGC project says simply SB0. Its redshift puts it at 77 million light-years which would support the non-interacting status if a true distance indicator. Analysis of its globulars using a somewhat different process than that used for NGC 4762 puts it at 46 million light years, Tully-Fisher measurements average 55 million light-years while an analysis of its surface brightness function puts it at 53 million light-years. Yet another globular cluster measurement using the same method as for NGC 4762 puts it at 60 million light-years. Averaging these gives 55 million light-years. Again a case of pick one.

Still, these measurements for each galaxy do overlap suggesting they may be really at about the same distance. Maybe they aren't non-interacting after all. There aren't any obvious candidates that I could find to cause the distortions both of these galaxies exhibit. So while not interacting today they may have a few hundred million years ago. I found nothing suggesting this, however.

The pair was discovered by William Herschel on March 15, 1784. Neither are in the two H400 observing programs.

There are two asteroids in the image. The obvious one is (7027) Toshihanda at magnitude 17.4. The naming citation reads: "Toshihiro Handa (b. 1959) is a research associate at the Institute of Astronomy, University of Tokyo. He works in the area of radio astronomy, studying interstellar matter in our Galaxy and nearby galaxies. He is also active in public outreach in astronomy and astrophysics."

The other is very hard to see. It is (157814) 1995 WU28 at magnitude 19.1. Its trail runs in front of NGC 4762 which pretty well drowns it out. See the annotated image for finding it. I took the L images on either side of the meridian with color frames in-between the first luminance series were taken mostly to the east side of the meridian while the last three were taken when it was on the west side.

Not much exciting in the annotated image except for the galaxy group SDSSCGB 02665 on the east edge of the image. It is said to consist of 4 members at 1.6 billion light years. Two appear quite bright. I see several other faint ones in the immediate area bringing the count to 6 or so rather than 4. Of the two bright galaxies, the upper one lies within a second of arc of the position given for the group. No redshift is given for the galaxy itself though it may look like it in the annotated image. That line, however, is pointing to the group's position. The southern bright galaxy does have redshift data and is identified. Several quasars lie just outside the boundaries of the image frame. Oddly redshift data is limited to the eastern side of this image.

There are two blue smudge galaxies in the image without any redshift distance. They could be members of the same group as the two major galaxies. I've identified them in the annotated image. [SDV2005] 226 is listed as a dwarf elliptical while VCC 2093 is listed as a dwarf E3 elliptical.

14" LX200R @ f/10, L=7x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for NGC4762

NGC4775

NGC 4775 is a small spiral with an off-center core and distorted spiral arms. When the core is well off center, as in the extreme example of NGC 5474, the galaxy is often said to be "sloshed" -- not drunk -- but like sloshing an uncooked egg in a frying pan before it congeals puts the yoke off center. Usually, this is due to tidal forces of a much larger galaxy such as M101 in the case of NGC 5474. In the case of NGC 4775, the cause may be something else.

NGC 4775 is located in Virgo, right in the geostationary satellite belt as seen from my latitude which created havoc with satellite trails right through the galaxy, several right on top of each other making removal "interesting" to say the least. Redshift puts it 88 million light-years distant while a single Tully-Fisher determination says 87 million light-years. A surprisingly similar result. If right it is beyond the main Virgo Cluster galaxies. NED classifies it as SA(s)d while the NGC project says Sc. At the 88 million light-year distance it is about 54,000 light-years across. Rather typical for a spiral galaxy.

It was discovered by William Herschel on April 17, 1784. It isn't in either H400 program.

This image was hurt severely by clouds. Only one blue frame and one luminance frame were reasonably free of clouds. This dropped my limiting magnitude severely. There are a lot more background galaxies than I was able to show. Though since this field is outside the Sloan Survey field only the brighter ones had any data in NED. All but one galaxy in the field that NED has redshift data for were seen in my cloudy image. The Abell Galaxy Cluster 1634 is centered southwest of NGC 4775. It is listed as class 1 which is 30 to 49 galaxies in an 18' diameter field with a distance of 2.4 billion light-years. Several of the galaxies have redshifts that are at about this distance. It is listed as morphology III which has no anchoring cluster galaxy. I've drawn a line to the position NED has for its center though they list its center only vaguely within a 2.5' error circle.

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

Related Designations for NGC4775

NGC4800

NGC 4800 is a nearly face-on spiral galaxy in Canes Venatici about 6 degrees west of M51. It is about 50 million light-years distant by redshift but nearly twice as distant, 94 million light-years by non-redshift measurements at NED. I have no idea which is closer to correct. Some sources said the distance was unknown or unavailable, one split the difference and said 72 million light-years. Nor did I find anything saying it was part of some galaxy local group. Though SIMBAD says it is a galaxy in a group of galaxies it doesn't tell me which they are.

Most online images (very few) show little detail in this galaxy, the exception is a couple HST images. I was rather surprised that it wasn't nearly as featureless as I had been led to believe from what few online amateur images I found of it. My reason for imaging it was simply that when nothing else is within my meridian based imaging window I'm working on Herschel 1 and 2 program objects I can reach from my 47 north latitude. It was discovered by William Herschel on April 1, 1788. Appropriate as it fooled me into thinking it wasn't as interesting as it turned out to be. Even my comments from the H400 program gave it short shrift. My entry on the excellent night of April 29, 1984 at 150x with my 10" f/5 only says "Bright center, slightly elongated, hints of detail, beside a dim star." Usually, I wrote more than that.

The annotated image shows a couple of probable errors in NED's database. Southeast of NGC 4800 is a galaxy NED says has a redshift of 5.986982 putting it nearly 13 billion light-years distant. This is beyond most quasars, certainly most I can image. No way I could see a galaxy at that distance. Even Hubble's deep field rarely goes that deep. To the southwest is another with a redshift of 3.767008 that puts it just over 12 billion light-years distant. While my image shows it as round, the Sloan image shows it an edge on spiral. I only picked up the core. Using NED's length of 0.19 arcminutes it would be 660,000 light-years across. Huge by today's standards but downright beyond belief for the early universe. I'm sure these distances are in error. Both are more distance by NED than any quasar in the image. I've marked them with ??? For those wishing to look into this, they are SDSS J125456.22+462553.2 and SDSS J125403.49+462527.8 respectively. Oddly they indicate both have proven spectroscopic redshift determinations.

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

Related Designations for NGC4800

NGC4845

NGC 4845 is an apparently warped, rather red, spiral galaxy in central Virgo. Redshift puts it about 72 million light-years distant and Tully Fisher estimates agree rather closely. William Herschel discovered it on February 24, 1786. It is a rather flat galaxy lacking much of a central bulge. In fact, a significant part of its core is hidden behind a rather thin dust lane indicating how small the core is. The galaxy is thought to have a rather small black hole in its core to go along with its small central bulge being only 300,000 times that of our sun. Still, in January of 2011, it is thought it's black hole might have devoured a rogue planet that got too close to its core. You can read about it at this link: http://www.universetoday.com/101172/astronomers-watch-as-a-black-hole-eats-a-rogue-planet/#more-%20%20101172 which contains a link to the paper the article is based on.

NGC 4845 has another mystery. It might be long lost NGC 4910. It was found by William Herschel prior to NGC 4845 on January 24, 1784 but he admitted his coordinates were poor. Here's what the NGC Project says on this matter:

"NGC 4910 may possibly be NGC 4845. There is nothing in WH's place, and Dreyer
quotes WH's note in the Scientific Papers: "The place of this neb. is not
determined with accuracy." Dreyer adds, "No modern observations known."

"WH referred two other nebulae -- NGC 4420 and NGC 4772 -- to the same
comparison star (75 Leo). For N4772, Dreyer notes, "RA 40 seconds too
great." This suggests that WH's RA for N4910 might also be too large. In
that case, NGC 4845 would be a candidate for WH's object. It is a large
galaxy at about the right declination. However, WH describes his nebula as
"eF, vL, er, R. 7 or 8 arcmin d[iameter]." N4845 is not quite that large,
nor is it round. It is, however, the only reasonable candidate, so I've
adopted the identity, though with a query. - Dr. Harold G. Corwin, Jr."

What caused the warping of NGC 4845? I found no papers even mentioning it is warped let alone discussing its warped nature. That mystery will remain unsolved for a while longer it appears. Or is the warp just an illusion? Looks real to my eye. NGC 4845 is one of the original Herschel 400 objects. All this gave me several reasons for putting it on my to-do list. My log entry dated April 23, 1985 using my 10" f/5 at 50x on a fair night with a moon simply reads: "Large, elongated galaxy, slightly brighter toward the center."

To the northeast is FGC 1530 a really flat blue galaxy seen edge on. Though no dust lane is seen. Redshift puts it 140 million light-years distant or twice the distance of NGC 4845. In this case, the Tully Fisher distance estimates for it are wildly discordant. One estimate from 2000 says it is only 5 million light-years away. Obviously, something is wrong with that estimate. Another from 2010 comes up with three results depending on the interpretation of the results. It gives 91, 92, 94 million light-years. That's only 65% of the distance redshift comes up with.

There were 5 asteroids in the image though 2 are so faint they didn't survive the JPEG compression. I left their location marked as some faint hint is still seen of them. Their details are in the annotated image. This field is one not covered well by catalogs other than those that reference galaxies by their coordinates. For those, I just use G or Q for Galaxy or Quasar without including their coordinate name as that is available by plate solving my image. UvES objects are listed as being quasar candidates with only photographic redshift measurements.

Conditions were poor for this one. While seeing was only somewhat below average this night, like the previous one had rapidly falling temperatures. So rapid that tube currents developed again flattening stars though not as much as the previous night. This put a lot of ice crystals into the air which dimmed the image as well as creating huge halos around bright stars, especially the brilliant F2 HD 112542. Even though it was only 7th magnitude its glow covered one third of the image making for processing nightmare.

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

Related Designations for NGC4845

NGC4866

UGC 08091 is a dwarf irregular galaxy likely part of our local extended group of galaxies. Distance estimates ranged from 3 million to 7 million light-years with 3.65 million light-years being the median value of 15 estimates at NED. Redshift is worthless this close. It would indicate about 24 million light-years which is certainly not reasonable. The galaxy is full of star knots in what appears to be a random pattern. It is located in Virgo so is seen against the Virgo cluster of galaxies but isn't a member of that group, nor is the other major galaxy in the image NGC 4866. UGC 08091 has a very blue color indicating a lot of recent star formation as such stars live only a few million to tens of millions of years rather than the 10 billion years a star such as our sun would live.

NGC 4866 lies at a distance of about 100 to 110 million light-years by redshift though some other estimates place it closer at about 52 million light-years. If correct that would put it in the Virgo cluster but most of the measurements place it in the 80 to 95 million light-year range. The majority would argue that it lies beyond the Virgo cluster. It is a starburst galaxy that NED classes as SB(rs)bc with HII emission. That emission is confined to the core region where the starburst activity is going on but hidden from our view by the obscuring dust around the core. Otherwise, it appears a rather dead galaxy as the disk stars are mostly of a slightly cooler type than our sun making it appear star formation in the disk ceased millions or even billions of years ago.

NGC 4866 was discovered by William Herschel on January 14, 1787. It is in the original Herschel 400 observing program. My entry from April 23, 1985 with my Cave 10" f/5 at 50 power due to poor transparency from ground fog reads: "Edge on galaxy with two bright objects near the center. One may be a star but seeing has deteriorated too much to tell for sure." Apparently, I was seeing the blue star and core of the galaxy though the star doesn't appear "near" the center and the core is in the exact center. Maybe my brain was as foggy as the skies that night.

As with many images, this spring weather did a number on this one. I had to throw out 3 of 7 luminance frames 3 of 5 red and green frames and 2 of 4 blue frames due to clouds killing the data beyond usefulness. I'm surprised I got as much as I did.

As usual, I happened across a couple galaxies not in NED. The faint fuzzy to the southwest of NGC 4866 was one I hoped to find something on. Is it a close dwarf of very low surface brightness or just what is it. I know it isn't a reflection as it shows in the Sloan Survey image but isn't in NED's database of Sloan data. Another galaxy to the far east was missing too when I looked it up. Usually, it is the faint blue fuzzy that gets missed as with the first one mentioned but this second one doesn't fit that description. An HST image of it can be seen at: http://cseligman.com/text/atlas/ngc4866hst.jpg

One distant fuzzy is listed in NED's Sloan data as both a galaxy and a quasar. Since they preferred the quasar label I listed it that way first on the annotated image. At only 3.62 billion light-years it is rather dim for a quasar. It's in the lower right corner. Near the upper right corner is a small galaxy cluster. The position is about 1 second of arc different from the big cluster galaxy that anchors the group. I put the label on the big cluster galaxy as it overlapped the position of the cluster. Both have a photographically determined redshift which don't agree. I have no idea which is the one most likely to be closest to the correct distance. They only vary by 150 million light-years so this isn't a major issue.

14" LX200R @ f/10, L=4x10' RGB=2x10' though one green is not contributing much, STL-11000XM, Paramount ME

Related Designations for NGC4866

NGC4893

My main subject of this image was NGC 4893 in the image center but the field turned out to be far more interesting than I suspected. The field is in Canes Venatici about 1.5 degrees southeast of Cor Caroli, the constellation's brightest star. NGC 4893 is either one or two galaxies depending on who you read. The NGC Project considers it two galaxies made up of IC 4015 and IC 4016. NED and Seligman consider NGC 4893 to be only IC 4015. IC 4016 is sometimes known as NGC 4893A which Seligman calls stupid since it already has a perfectly valid IC designation. First time I recall that term used in naming galaxies. Actually, there's a third member of this group, starlike ASK 519181.0. NED refuses to classify any of these. The NGC Project says the northern galaxy is S? while Seligman gives it two classifications. Under the NGC 4893 number he says E2? but under the IC 4015 entry he says E2? pec?. The galaxy was first discovered by Heinrich d'Arrest which Dreyer recorded as NGC 4893 on April 24, 1865. On March 21, 1903 Max Wolf found it but got the coordinates a bit off so Dryer recorded it as a separate entry in the IC catalog as 4015.

IC 4016 was found by Wolf at the same time and given the entry IC 4016. NED again doesn't classify it, The NGC Project says S? while Seligman gives two classifications for it. Under his discussion of NGC 4893, he says IC 4016 is S?? (that double question marks again) while under its own entry in the IC section of his web page he says it is S0? pec, only one question mark.

It is quite obvious these two galaxies and likely the third are interacting and have been highly distorted. It could be the starlike galaxy has lost all its outer stars leaving only a core. The mess is about a half billion light-years distant. I'd love to have the HST look at this mess as I was unable to find any detailed images of this group. Measuring the size of these considering that they are in common halo is difficult. I measured the east-west halo diameter of each rather than the larger combined north-south halo. That gives a size of 104,000 light years for NGC 4893 and 40,000 for IC 4016.

Several other NGC galaxies are in the image. In the upper right corner is the classic spiral NGC 4868. It is listed as SAab? by NED, Sa by the NGC Project and type Sab? by Seligman. It was discovered by William Herschel on March 17, 1787. At only 220,000 light-years it is less than half the distance of the NGC 4893 group. While it appears much larger that is due to it being much closer. I measure it at just about 100,000 light-years in size. It isn't in either of the Herschel 400 observing programs.

Far larger in the upper left corner is NGC 4914 a huge shell elliptical galaxy. I had no idea of the shells as nothing I read before taking the image referred to them. The shells extend far out though they don't come through well in the color image due to my insufficient exposure time. If you look very closely you can see the northern shell extends to near the top of the frame. This makes the galaxy huge. I measure it at 380,000 light-years. If only the shells obvious in the color image are used it is still 234,000 light-years across. Classification confusion continues as NED and the NGC Project say simply E, Seligman says E4 while one paper says E5/S0. No one mentions the shells but the paper thinks it has found within the galaxy the remains of one it ate. Shells are the result of such a diet so they may be right. I couldn't find it however in my image and only a faint hint of it in the Sloan image. It was discovered by William Herschel the same night as NGC 4868 and is in the second Herschel 400 observing program. Unfortunately, my notes for that program didn't survive the move up to Minnesota.

We aren't done with NGC galaxies in the image. In the lower right corner is NGC 4870. NED again refuses to classify it. The NGC Project says S while Seligman says S(rs)a?. It was discovered by Lawrence Parsons on April 1, 1878. I measure it at 137,000 light-years in size. At nearly a half billion light-years distant it is likely a member of the NGC 4893 group. Its disk has an odd gap in the northern half not seen in the southern half.

IC 4027 as a barred spiral that too is likely a member of the NGC 4893 group. While NED doesn't classify it Seligman says SB0?? (that double question marks again). Max Wolf had a very productive night on March 21, 1903 having found this and the next three IC galaxies all as well as others mentioned above that night. I measure its size at about 72,000 light-years.

Next is IC 4034 which only Seligman classifies saying it is E0?? trying to drive me nuts with that double question mark again. I measure its size at 56,000 light-years. At 400 million light-years it apparently is not part of either of the two main groups in this image but does have a companion, IC 4038. Only Seligman classifies it and to drive me insane says it is S0??. It has some faint extensions that give it a somewhat larger size of a bit over 100,000 light-years.

The last IC galaxy in the image is IC 4043. Finally, NED classifies it saying Sc-IRR. Apparently, it can't make up its mind. I can't recall that combination before. Seligman has the same indecision as he says SBd/Irr?. At least only one question mark this time. It appears to be part of the group of much larger galaxies at 220 million light-years. I measure it at 74,000 light-years in diameter

This field is full of double identities and even a triple. ASK 519150.0 is also listed as LEDA 2096904 at the same position but different distance. A quasar is listed at twice also at two very slightly different distance. While I annotated only one entry for ASK 519156.0 it is also listed at a very slightly different distance under a Sloan survey ID and at yet another very slightly different redshift under a 2MASS designation. All round to 2.61 billion light-years so I didn't note this. Still, I've not run into this before in any field I've taken.

To add to the confusion there's a neat low surface brightness, very blue galaxy on the eastern side of the image near LEDA 2094904 (another galaxy likely part of the NGC 4893 group). This galaxy isn't listed in any survey I have. Yet NED shows an entry in the Sloan survey for what to me looks like a piece of a north going arm. I've noted it in the annotated image though the galaxy itself gets a question mark (only one) since I can't find it anyplace. Well below this object is LEDA 2092313 a dwarf likely related to the others at about 220 million light-years. it has a bright star cloud at its southern end. At first, I thought it might be a field star but I've verified it is a star cloud in the galaxy. There's lots more to explore in this image but it would take a book to cover it all and I've likely lost 99% of you by now anyway.

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

Related Designations for NGC4893

NGC4911

NGC 4911 is one of the few spirals in the Coma Cluster. Due to interaction with NGC 4911A to the southwest, the galaxy is surrounded by a huge faint plume of stars pulled from it. Other galaxies in the cluster have similar large plumes around them such as the red disk galaxy NGC 4919 about 5 minutes east-northeast of NGC 4911. The HST has taken the best image of this galaxy and has a more complete discussion about it. If you have decent internet service ignore the warnings and download the "highest-quality" image, about 15 megabytes in size.
http://hubblesite.org/newscenter/archive/releases/2010/24/image/

The largest and brightest spiral in the Coma Cluster is NGC 4921. It is rather red and the arms rather indistinct as star formation is very low in this galaxy. Likely collisions and encounters with smaller galaxies in the cluster has stripped it of most of the dust and gas needed to fuel star formation. Star clusters often kill galaxies as the constant close encounters and mergers disperse the dust and gas that would fuel star formation. Spread around the core of the cluster it is too hot to condense to form more stars or galaxies. Maybe in billions of years as the galaxies in the cluster cool and die this dust and gas will cool and condense sufficiently to create more galaxies. Or will the radiation of the first stars to form disperse this gas preventing and further star formation? A more complete discussion and false color image of this galaxy by the HST is at:
http://spacetelescope.org/news/heic0901/
The orientation is similar to mine being rotated a bit clockwise from north at the top.

Containing over 1000 galaxies the Coma Cluster -- Abell 1656 is the largest, richest "nearby" galaxy cluster being about 320 million light-years away. It is anchored by the two huge elliptical galaxies, NGC 4874 and 4889. NED puts the long diameter of NGC 4889 at 2.8 minutes of arc. That would make it about 260,000 light-years across. In December 2011 it was announced this galaxy is the home of the largest known black hole with a mass of 21,000,000,000 solar masses. Though the error bar for this is huge ranging from 6 to 37 billion solar masses! NGC 4874 is nearly as large but apparently doesn't harbor a record-smashing black hole. It has another number 1 claim. It has 30,000 globular star clusters. Though, many, like some around our galaxy are now thought to be the cores of dwarf galaxies it has been "feeding" on for the past few billion years. The stars were stripped from all but the cores of these dwarf galaxies leaving something that looks much like a typical globular cluster, only larger.
http://www.spacetelescope.org/images/potw1138a/
To confuse this globular issue a note at NED reads: "The power spectrum for NGC 4874 is clean and the fit is very good. NGC 4874 has a normal globular cluster population." http://iopscience.iop.org/0004-637X/550/2/503/pdf/52870.web.pdf (page 520)
I'm not sure how you reconcile these two statements.

Obviously, doing one of my typical annotated images would be a masochistic nightmare. Instead, I did note all NGC, IC and CGCG, KUG and GIN galaxies. Distance was not noted as all are at members of the cluster so are about the same distance from us. I left out several hundred of 2MASS and Sloan Survey cataloged galaxies. I also saw over one hundred very distant galaxies listed. I decided to mark those over z=0.5. Then I ran into a problem. Most were from a catalog listed as [ANM98]. After trying to locate 10 of them without success I gave up. NED lists their position as uncertain. But does indicate they should be in a 30" error circle. With so many galaxies in such a small area, a 30" error circle made identification impossible. There was no explanation for this huge error bar. One from the Sloan survey at 5.9 billion light years and fainter than nearly all of the unidentifiable galaxies was easily found under NGC 4874. I did mark that one.

Normally I'd go into who discovered these many galaxies and when but there are just too many. I covered some of them in the ComaCluster post. You are on your own for the others.

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

Related Designations for NGC4911

NGC4922

NGC 4922 is a pair of colliding galaxies on the northern edge of the Coma Galaxy Cluster that Arp didn't include in his atlas. Some papers see three galaxies here but most see only 2. NED shows no object at the position of the middle galaxy of the three. Nor can I see anything there in the Sloan image though that is overexposed. No matter how I stretch my image is anything seen at the middle galaxy's position: 13h 01m 24.67s +29d 18' 33.0". I'm only going to address the two seen in my image.

The southern galaxy is listed by NED as Sb Sy2. How you get Sb out of that mess I don't know. Likely that's a good estimate of what it was before the collision. It does have a nice blue plume to the south but otherwise is surprisingly red in color. The northern galaxy is listed at NED as S;HII;Sy2 LINER. That's a lot for that little guy. The NGC project has a classification of E0 for NGC 4922. I can't tell if that is for one of them or both or what. In any case that's quite a difference of opinion. The Seyfert classification of both is likely due to the black holes being well-fed thanks to the collision in progress. The strong red color of both would seem to indicate there's been no star formation in these guys except the outskirts for a few billion years. Something seems to have stopped star formation long ago. The plume, however, is very blue so has new stars. The pair was discovered by Heinrich d'Arrest on April 19, 1865.

Several other Coma Cluster members are in the image, many are small and many have very low surface brightness. For that reason, I labeled by name those that appear likely cluster members. The big ones have IC numbers or an MCG listing. The rest have rather obscure and usually quite long catalog names.

While the cluster with the common name of Coma Cluster is Abell 1656; a much smaller, in angular size at least, Abell 1661 is also in the image but instead of being about 330 million light-years distant like the famous Coma Cluster, it is 2 billion light-years away and can be found in the lower part of my image a bit left of center. Right below it is a pair of galaxies, one a member of the Coma Cluster (famous one) and the other a much more distant galaxy though they do look like they are very close together they are some half billion light-years apart.

Several other distant galaxy clusters are in the image if the distance to the anchoring bright cluster galaxy is different than that of the cluster by redshift measurement I list both with the cluster's distance first. If the distance has a "p" after it it is photographically determined which carries less accuracy than spectroscopic distances. If the BCG has a spectroscopic distance that is likely the more accurate of the two.

I was rather surprised to find only about 3 quasars in the image.

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

Related Designations for NGC4922

NGC4938

NGC 4938 is a barred spiral in northern Canes Venatici about 380 million light-years distant. It sits in front of a distant galaxy group about one and a half billion light-years distant. What drew my attention is that the southern part of the galaxy is much brighter than the northern though the features, if you ignore brightness, is rather symmetrical. It was discovered by John Herschel on February 17, 1831. I measure its diameter at about 88,000 light-years.

Also drawing my attention to this field is UGC 08168 near the top of my image. It appears to be the result of a collision of two galaxies as it has two red cores each with a huge plume or arm. To the west of the lower core is a huge blue star cloud. I suspect it was created by the collision but it may just be a third galaxy. I doubt that it is. This collision is unrelated to NGC 4938 being nearly 160 million light-years further away. It must be a spectacular sight for any beings much closer to it. The size of this train wreck is about 195,000 light-years including the plumes. I suspect the individual galaxies were less than half this size prior to their smash-up that scattered stars far and wide.

There appear to be two galaxy clusters listed in my field. Both are at a distance of about 1.5 billion light-years and contain lots of galaxies spread over a wide area. They do overlap. Could this just be one cluster but with Zwicky and Abell not agreeing as to the position of its core? Neither show a galaxy, large or small, at the center point of the clusters. The Zwicky cluster appears to be behind NGC 4938. One galaxy can be seen through NGC 4938 that is listed as being the Bright Cluster Galaxy for the small cluster of 23 galaxies. The cluster is listed as being 1.4 billion light-years distant though by some error the bright cluster galaxy is shown at a distance of only 380 million light-years, the same as NGC 4938. It can't be both a bright cluster galaxy and a tiny dwarf being eaten by NGC 4938. That Asian astronomer Sum Ting Wong seems to be involved here. He didn't stop there, however. Another galaxy just south of NGC 4938 is listed at the position of a 13 member group. The group is at 1.45 billion light-years while the galaxy is again at 38 million light-years. Both the bright galaxies at this 380 million light-year distance are listed as having their distance determined by the Friend of a Friend method. I don't understand this method. It appears they just assumed these are at the same distance of NGC 4938 and ignored others considering them members of more distant groups. I'd think this discrepancy would merit at least a mention at NED but I found nothing on it. I think it quite likely these small groups are parts of the larger Zwicky and Abell clusters.

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

Related Designations for NGC4938