ARP156

Arp 156/ UGC 05814 belongs in his category for disturbed galaxies with interior absorption. I believe the latter refers to the dust lane. Arp's comment reads: "Very faint oval loop in north-following-south-preceding direction. "North-following" means northeast and "south-preceding" is southwest. NED classifies it simply as Peculiar. The CGCG catalog says of it: "Post-eruptive spiral with double core (blue and red), pronounced absorption line." I don't see that double core in my image or the Sloan image (only other color image of this galaxy I could find). unless this refers to the portion of the core above the dust lane (slightly red) and the portion below the dust lane which is less red though I'd not call it blue. http://skyservice.pha.jhu.edu/DR8/ImgCutout/getjpeg.aspx?ra=160.65848773&dec=77.4947972&scale=0.79224&width=512&height=512&opt=&query=

Other than the above I found virtually nothing on this object. It sits quite alone in northwestern Draco nearly a half billion light-years from us. This means the galaxy is huge. From one side of the plumes to the other it is 140 arc seconds (over 2 minutes) across. That puts it over 330,000 light-years across. Ignoring the plumes it is a more reasonable 120,000 light-years in diameter. Still likely larger than most galaxies. I suspect it got its size and its plumes from merging with other galaxies though I found no neighbors in its area. Did they all get eaten? NED has no redshift data on any other object in the field so I've not prepared an annotated image.

This is another Arp that was lost on my hard drive after getting misfiled due to not having calibration run automatically as the data was taken. In this case, my notes indicate I was going to revisit it for more data but that never was recorded in the database that controls what the scope images so it never happened. Rather than wait for next year I processed what I have so far as it is my normal exposure times. Though it is obvious that the luminance frames (well three of the four) were hit by clouds. Likely why I was planning on more data to help bring out the plumes. Green also suffered a nasty hit but I think I have the color reasonably close despite the skies attempts to thwart my efforts.

Arp's image is at: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp156.jpeg

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

Related Designations for ARP156

ARP157

Arp 157/NGC 520 is located in the constellation of Pisces the fish below the Great Square of Pegasus. This one has been the source of some debate over the years. Today it is seen as two galaxies in the process of colliding and likely merging. But in Arp's time, it was seen as a single galaxy similar to M82 though oddly he classed M82 in his miscellaneous category while Arp 157 is classed as Galaxies (not classifiable as S or E) disturbed with interior absorption. So he was apparently on the fence with this issue. Even as late as the 70's the debate was unsettled. Comments like this were in the literature of that era: "Inspection of the original plate suggests that NGC 520 is not a collision of two galaxies but rather a system of the M 82 type (Sandage)". It appears the images of that era just didn't show the detail that today's do. In my image, you can clearly see two galaxies. One appears of the type of NGC 3628, the hamburger galaxy, in Leo. It's dust lane dominates and also hides the core same as with NGC 3628. The core of the other galaxy is seen to the northwest (upper right) with a more steeply tilted dust lane below it. The interaction has created lots of tidal distortions. The main one being a tail that first goes down then arcs to the east (left) and comes back up as a very faint fan. I've seen comments that it does or may connect to UGC 957 the big fuzz blob to the upper right of Arp 157. That isn't seen in my image though it may show with more exposure time. Arp 157 has a redshift distance of 90 million light-years while that of UGC 957 is 85 million light-years by its redshift. Close enough that they may have gravitationally interacted in the past. Though it's rather symmetrical shape would argue against that. Few galaxies in the image have redshift distances.

The galaxy was discovered by William Herschel on December 13, 1784. It isn't in either of the Hershel 400 observing programs, however.

Even the rather bright disk galaxy below and left of Arp 157, PGC 5195, has no redshift data I could find. About the only other object with redshift data is the quasar [HB89] 0121+034 at 3.7 billion light years. Follow a chain of stars starting at the kink to the left of the tidal tail. Two faint stars, a rather bright orange star, a somewhat fainter star then a bit of a gap brings you to the very blue quasar. All lie in a nearly perfectly straight line.

At the top of the page are several galaxy clusters. It appears their members overlap. I was unable to separate which belonged to which cluster as individual redshift data wasn't available. Most of these red galaxies along the top above Arp 157 probably belong to NSCS J012431+040205 with 61 members at a redshift distance of 3.5 billion light years. The other two are XDCS cm J012437.8+040022 at 3.94 billion light years and XDCS mf J012435.6+040107 at 4.46 billion light years.

5 asteroids are also in the image. Nearest Arp 157 to the west (right) is (53883) 2000 FN39 at a listed magnitude of 19.8 though it appears brighter than that. In the lower left corner is (58656) 1997 WT50 at magnitude 18.3. Along the bottom edge toward the lower left corner is (23843) 1998 QU106 at magnitude 16.6 so easy to spot. The remaining two are more difficult. (131277) 2001 FB69, magnitude 19.4, lies below the upper left corner near a rather obvious orange star. Right in the upper right corner is (35745) 1999 GZ30 at magnitude 19.2

Hubble has taken a great image of this galaxy. It can be found at http://hubblesite.org/image/2342/news_release/2008-16 and is south up so appears upside down. Note the star cloud easily resolved by Hubble made up of super hot very young stars along the top edge of the Hubble image. It appears as a blob near the top of the tidal arm in my image. I can't begin to resolve the stars thanks to our atmosphere. Since we appreciate being able to breathe I can't do much about its distortions. The Hubble page gives a different distance estimate of 100 million light years. Since Hubble has managed to resolve some stars its estimate may be more accurate than pure redshift estimates. If you have the bandwidth I recommend downloading the largest image.

ESA released their image of this galaxy taken with a scope with 100x the light grasp of mine and from atop one of the premier imaging locations in the world. Their image is at http://www.eso.org/public/usa/images/potw1048a/ I was rather surprised that their much larger scope under much better skies didn't do much better than I did. Their observatory that took their image (I don't know which of the two was used) is at:
http://www.eso.org/public/archives/images/screen/ib-la-silla05.jpg
The scopes are mounted high above ground level to avoid seeing problems at ground level. I did the same but am only up a bit over 16 feet due to zoning limits on the height of buildings around the lake -- and cost of course.

Arp's photo of the galaxy is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp157.jpeg

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

Related Designations for ARP157

ARP158

Arp 158 is NGC 523/537. It is a very strange galaxy. Arp put it in his category: Galaxies (not classifiable as S or E); Disturbed with interior absorption. I'm not sure what that means. Centaurus A (NGC 5128) also falls in this category though I won't be imaging it of course as it is always below my horizon. Redshift puts it about 200 million light-years away. Analysis of a type 1a that blew in 2001 (or I should say was seen here on earth that year) indicates about the same distance. That's about the only agreement on this galaxy I could find. Here are some Notes on it at NED.

"Post-eruptive, blue, 3 compact knots connected by bright bar, fan-shaped
jets and matrix' (CGPG)"

"Possibly a colliding or strongly interacting pair. Compact core."

"Peculiar spiral, with two nuclei on sides (east-west).
Chincarini G., and Heckathorn, H. M. 1973, Pub. A.S.P., 85, 568.
claim that the west nucleus is a foreground star,
but our measured redshift is similar to that of the east one."

It's quite obvious the westernmost object along the bar is just a foreground star. I have no idea where the idea comes from it is part of the galaxy or how its redshift could possibly be measured so poorly. The blob on the east end could be the core of a galaxy it is merging with. Wish we could see it from another angle. Seems to be virtually edge-on. NED classes it simply as peculiar.

Other than these notes and the articles they came from I found little on it. Thanks to better than normal seeing I was able to image this one at 0.5" per pixel though the seeing didn't hold for long. I really needed 20 minute subs as 10 contain too much read noise. Also, I normally consider 80 minutes the very minimum but only got 60 so this one is far noisier than I'd like.

This one appears to be part of the Pisces group though located just across the border in Andromeda. Arp 229 is also a member of this group.

The story of its discovery by William Herschel is quite interesting but too long to post here. Go to the NGC project page: http://www.ngcicproject.org/dss/dss_n0500.asp and scroll down to either NGC 523 or NGC 537 and click on the data button (not the image). Then scroll down to Historical Research Notes for the story. Think you have had a bad night at the scope? Seems William was having a really bad night at the telescope the night he recorded this one resulting in two NGC entries for one object. The night he got it correct was September 13, 1784. That resulted in the NGC 537 entry. Heinrich d'Arrest corrected Herschel's error for NGC 523 on August 23, 1862 and gets credit for this version. It isn't in either Herschel 400 observing program.

Arp's excellent image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp158.jpeg

14" LX200R @ f/10, L=6x10'x1 RGB=2x10'x2, STL-11000XM, Paramount ME

Related Designations for ARP158

ARP159

Arp 159/NGC 4747 is a very distorted galaxy in Coma Berenices not far from the famous Coma Galaxy Cluster, about 68 million light-years distant by redshift. By Tully-Fisher measurements, it is closer, about 40 million light years. I suspect this to be more accurate. I'll get back to why in a bit. Arp put this one in a category based on the dust clouds near the core rather than the tremendous star plumes. It is in his galaxies (not classifiable as S or E) disturbed with interior absorption. Centaurus A is the most famous galaxy in this class. Arp saw the northeast plume saying: "Very faint plume extending northeast." He didn't mention the shorter and fainter southwest plume. Nor do any of the notes at NED. The NE plume extends much further in my image than I can see it in Arp's image. NED classes it as SBcd pec.

Obviously, something happened to create these huge plumes and so disturb the galaxy. There's no hint of any galaxy in my image that could do it. But just beyond the image is an even larger disturbed galaxy, NGC 4725. Its redshift is almost identical to that of Arp 159. Analysis of its Cepheid variables as well as Tully-Fisher measurements put it at about 40 million light years. With both measurements the same for Arp 159 and NGC 4725 it appears quite likely these two tangled in the past. Tully-Fisher can be quite accurate with spirals seen at an angle as these two are. For the two to agree like this I suspect it is giving a more true distance estimate. The redshift being due to their common motion through space as indicated by their apparent interaction.

I imaged 4725 when I first went digital using the same scope and camera but different focuser and distance behind the main mirror. This changed the image scale. My filters were different as well, not nearly as well matched to the camera's spectral response nor did I take G2V data for them. I was in ignorance mode back then. This made color balance difficult. I reprocessed that image as best I could and made an attempt to combine the two images taken years apart. Having never tried this before and not taking either image with this in mind at the time the results aren't great but at least it does show the relationship of the two galaxies. The other galaxy with NGC 4725 is NGC 4712. It is a background galaxy with a redshift distance of a bit over 200 million light years. Obviously a distant background spiral galaxy.

NGC 4747 was discovered by William Herschel on April 6, 1785. NGC 4725 was discovered 4 days later on April 10, 1785 and is in the original Herschel 400 observing program. NGC 4712 was discovered by John Herschel on March 28, 1832.

My notes on NGC 4725 taken with my 10" f/5 on April 23, 1985 under fair but humid dimming skies with moonlight bothering using 50x reads: "Large, oval galaxy with star-like nucleus."

While the field is within the SDSS survey no distance data was found at NED for any galaxy in my Arp 159 image other than Arp 159 itself.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp159.jpeg

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

Related Designations for ARP159

ARP160

Arp 160 was in the news after an image of it combining white light data from Hubble and X-ray data from Chandra has been recently released and picked up by many astronomy news websites. I imaged it the night before the image was released so have rushed it to the top of the processing list.

Arp 160 is known as the Medusa Galaxies though Arp never even knew it was two galaxies. He considered it one and classed it as a galaxy not classifiable as "either elliptical or spiral that is disturbed with interior absorption". In fact, it is two galaxies that are in the process of merging. The fan-shaped blue object above and the spiral-like, mostly reddish object below. Using Chandra's X-ray vision (better than Superman's) the black hole that was at the core of the upper galaxy has been spotted proving it is two galaxies.

The Chandra press release is at:
http://chandra.harvard.edu/photo/2009/medusa/

I had a heck of a time processing this image as there was a 5th magnitude star just out of frame at the top right that must have hit something reflective in the camera. It sent ghost images all over the field. Many overlapped. It took me a couple days work to remove them. In doing so I lost faint parts of the image but none involving Arp 160. Which is also known as NGC 4194 and is in Ursa Major. It was discovered by William Herschel on April 2, 1791. It isn't in either Herschel 400 observing program.

Arp's image with the 200" Palomar scope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp160.jpeg
Film has far less dynamic range than today's digital sensors so the core is burned out in Arp's image loosing the spiral nature of that region in an attempt to show the fainter parts.

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

Related Designations for ARP160

ARP161

Arp 161/UGC 6665 is thought to be a merger of two spiral galaxies located in western Virgo almost on the Leo border. It is about 270 million light-years distant. Arp put it in his class of galaxies with diffuse elements. An obvious reference to its cone-shaped jet/plume. Arp's comment "Faint, diffuse material extends away from neck." Several sources seem to see the bright region at the "neck" as Arp calls it, as a jet with the plume extending from it. While the night I took this was awful with resolution of only about 3.5" of arc or worse, the "jet" is really two point sources, better seen in the Sloan image. Also better seen in the Sloan image is the spiral structure of the galaxy. It was blurred out of existence by the horrid seeing I experienced the night I took my image. The plume appears the result of the merger and there is no "jet". The lower of the two star-like objects is shown at NED to be a 20th magnitude star on the Sloan survey. The upper, brighter object isn't listed at NED. Likely, it too is just a star in our galaxy confounding the issue. Arp had even worse seeing than I did so his image is of even less help here. Odd to out resolve the 200" scope when I'm having a bad night. Arp must have been desperate that night. I know the feeling.

NED classes the galaxy as Sb pec;HII;WR Sbrst. The starburst is likely due to the merger. I don't know what NED means by "WR". Usually, that refers to a Wolf-Rayet star. Anyone know what it means in the case of galaxy classification? NED's own reference page fails to define the term. All I can think of is the spectra has features of Wolf-Rayet stars. A starburst galaxy, like Arp 161, would likely have a strong population of such stars.

Near the bottom edge, left of center, is CGCG 012-064. It has the same redshift as Arp 161 so likely part of its local group.

The annotated image shows a galaxy cluster, SDSS CE J175.616547+00.441206 northeast of Arp 161 at 3.5 billion light-years. NED shows it with 24 members in a circle 3.8 minutes across. The center of the label marks the center of the cluster. No galaxy marked that point that I could see or NED mentions. One at that distance is seen however it isn't marked in NED as a bright core or cD galaxy. Still, it is likely a member of the cluster. Another cluster, MaxBCG J175.68388+00.38916, at 3.2 billion light-years is also northeast of Arp 161. It has 17 galaxies but no size was listed. A bright core galaxy is shown at the same position but without a distance estimate. I show it as GC/G with the galaxy distance a question mark. I'm not done yet! A third galaxy cluster at 3.2 billion light years, SDSS CE J175.678543+00.482395 is further northeast. It has no galaxy at its core though a red one is just right of the core with the label for it to its immediate left. The cluster is listed as 1.6 minutes in diameter containing 23 galaxies. Don't think we are done with galaxy clusters in this image. Mostly east from Arp 161 is the galaxy cluster SDSS CE J175.833755+00.375661 at 3.9 billion light-years. It is 3.6 minutes in diameter with 23 members, one of which has a redshift value of 4.0 billion light-years. I used one label for both though they aren't at the same position. The center of the cluster is behind the glare of a bright star while the galaxy, and a second one without a redshift measurement are just southeast of the star's glare circle.

Southwest of Arp 161 is a trio of objects. The most obvious a rather large galaxy, MGC 0023433/MGC 0096273 at 1.2 billion light-years. Why it has two designations I don't know. Above it is the Ultraviolet Excess Source, SDSS J114150.08+001314.3. At least that's how the Sloan survey categorizes it. The MGC calls it just a star as does the 2QZ. But with a measured redshift that puts it 9.5 billion light-years away, it sounds more like a quasar to me. There appears to be a possible tidal tail coming from the galaxy. Apparently, it is the separate galaxy SDSS J114150.87+001307.4 with an unknown redshift. Several other UvES objects with large redshifts are also identified in the image. I assume they are all quasar-like objects. I suppose it is possible they are extreme starburst galaxies but that these distances I find that unlikely.

Also to the northeast is a quasar, SDSS J114239.34+002640.4. While NED puts its redshift at z=1.872 for a distance of about 10.2 billion light-years one source, the 2QZ catalog gives a z of only 0.103 for a distance of about 1.3 billion light-years. This doesn't seem reasonable to me, especially for a 20.5 magnitude quasar so I went with the value NED prefers.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp161.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, STL-11000XM, Paramount ME

Related Designations for ARP161

ARP162

Arp 162/NGC 3414, located in Leo Minor about 80 light-years away is one strange galaxy. Arp put it in his galaxies with diffuse elements (filaments). It shows a huge halo and a diffuse disk. NED classes it as S0 pec. Modern rotational measurements show an interesting twist. The inner parts of the galaxy rotate one direction with maximum measured velocities along the disk as you'd expect but once you get out further suddenly the velocities slow and then reverse! But now are aligned on a different axis rotated 10 or 15 degrees counterclockwise from the disk. See http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2004MNRAS.352..721E&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf for the velocity map and other information. They draw no conclusions. I would suspect this is an indication of a merger. That would explain most of the features. The galaxy was discovered by William Herschel on April 11, 1785. It is in the original Herschel 400 observing program. I don't understand my notes from that, however. They were made on April 16, 1985 at 100x with my 10" f/5 under humid conditions. That apparently limited my ability to see faint objects as my entry reads "Small, round galaxy. Faint but easy due to its small size. A star-like nucleus seen with averted vision." Obviously, I was seeing only its center portion due to the conditions being worse than I realized.

From my image, it appears Arp could have also put it into his category for galaxies with shells. Though they aren't visible in his mono image taken in blue light with a yellow filter. I'm assuming that was done, it was his normal imaging mode. The shells show mostly in red light which he likely wasn't seeing. Shells are usually caused by mergers. It shows a LINER spectrum which is often caused by an interaction with another galaxy of some sort. It has two companions at about the same distance. I screwed up my position entry when programming the imaging of this galaxy and used the position of one of the companions, UGC 5958. This put Arp 162 at the top of my image and caused me to miss the more interesting companion NGC 3418 further north. The former has a redshift distance of 68 million light-years but a Tully-Fisher measurement of about 90 million light-years. NGC 3418 out of my image has a redshift distance of 70 million light-years and no other distance estimate. It's quite likely all three are actually about the same distance from us.

There's yet another member of the group though never mentioned as a companion that I saw. It is SDSS J105137.14+274919.6 at a redshift distance of 75 million light-years. It is east and a bit south of UGC 5958. It is classed as a dwarf though seems as large in angular size as UGC 5958 just with a much lower surface brightness. There are other galaxies closer to Arp 162 that are far smaller with similar redshift distance. These are noted in the annotated image. There's an obviously close galaxy similar to and further east and south of SDSS J105137.14+274919.6 that has no distance data. Many other dwarfs without distance data may also be members of the group.

The image contains at least 10 quasars, all in the upper 2/3rds of the image. One of them has a redshift of z=3.9 which translates to a light travel time of 12.2 billion light-years. A z of 3.9 means the light I imaged was well into the far ultraviolet region when it left the quasar. Most of its ultraviolet light is now seen here as infrared light it has been so red shifted. The quasar is now so far from us, nearly 24 billion light-years, that light it emits "today" will never reach us. The expansion of the universe will keep its "current" light forever beyond our reach. I use quotes because these words have no real meaning in Einstein's universe at these distances and speeds.

Many distant galaxies are in the image. Some with redshift data are over 4 billion light-years light travel time from us. They must be very large and bright galaxies for me to pick them up. My limiting galaxy magnitude is about 23 for this image. Must have been a good night.

Sloan image:
http://astronomerica.awardspace.com/SDSS-24/NGC3414.php

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp162.jpeg

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

Related Designations for ARP162

ARP163

Arp 163/Haro 09/NGC 4670 is an SB(s)0/a pec: BCDG galaxy in Coma Berenices. BCDG means Blue Compact Dwarf Galaxy. If the distance is 60 million light-years as its redshift and a couple other sources indicate then it is about 27 thousand light-years in size. Some sources put it only 36 million light-years away which cuts it down to 16 thousand light-years which certainly is a dwarf galaxy. Arp put it in his class of "galaxies with diffuse filaments, diffuse counter-tails." He left no comment about it. I can't see either filaments or a counter tail. Today it is thought to be rapidly forming stars but not at the starburst level. Still sufficient to color the galaxy blue due to the massive and thus bright blue stars it is making which cover up the far more common but much fainter main population of red stars.

With normal stretching or any of the canned stretches found in many programs as well as DDP and other techniques, the core showed just a bright white oval. I had to do some rather strong processing to hold back the core while the rest of the image was stretched to show what detail I was able to capture in the core region. The HST image of the core shows it better. That image is oriented with north to the lower right corner of the image while north is straight up in my image. The HST image (link below) is taken using near-infrared light for red with very blue light for green and near ultraviolet light for the blue channel. So the image is false color and won't match my visual light colored image. The Haro catalog entry describes it as "Muy violeta" which translates from Spanish to very violet indicating the UV light from these new stars really does color the galaxy. The Haro catalog is a catalog of blue galaxies and UV excess sources that have emission lines.

After I looked at Arp's image with the 200" Palomar telescope taken mid 60's I was expecting a rather featureless S0 or E galaxy so when this blue galaxy with star clouds and dust lanes showed up I first thought I'd missed my target. It's not often I can get this much more detail than Arp did using the world's largest telescope of its day. His log does show seeing as below normal for this image. Still, it is nice to beat the socks off that monster scope even with the help of modern technology.

The other NGC galaxy in the image is NGC 4673. While it appears slightly smaller it is some 5 times further away so actually much larger, about 120 million light-years across. That makes it more massive than our galaxy. It is classed E1-2 by NED and some other sources but S0: by the NGC project and a few other sources I looked at. So flip a coin. In any case, it appears to be a shell galaxy to me. At least I see what appear to be faint shells about it. If so it is the result of a merger in the past. Maybe several mergers. Oddly much literature refers to NGC 4670 and 4673 as a non-interacting pair. Since one is 6 times the distance to the other they aren't a real pair except as seen from our galaxy and others in the line of sight and couldn't possibly be interacting.

On the upper right below a bright star is the odd pair ASK 577888.0 and ASK 578732.0. The latter appears to be a knot in the former but NED doesn't call it part of a galaxy. It could be this is an interacting pair. This would explain the odd arm on the right side. I found absolutely nothing on this pair, however.

NGC 4673 seems to be the center of a rather large group of galaxies. At least there's a surprising number at its redshift in my image. This includes the ASK galaxies mentioned above. I found no cluster or galaxy group listed for the field, however. Though I didn't look far beyond the bounds of the image. There's another group at about 1.3 billion light-years also without a designated group or cluster.

Both NGC galaxies were discovered by William Herschel on April 6, 1785. Neither are in a Herschel 400 observing program.

Also in the image are two very distant quasars. Using NED's 5 year WMAP calculations the one in the upper right is 11.55 billion light years distant while the one on the left is 11.88. At these distances, things are very confusing. Redshift while linear at say 300 million light-years (double the redshift and the distance doubles) it is far from linear at these distances as the redshift z value of the former quasar is 2.989888 while the later only slightly further away is 3.439000. This also means the light was so severely redshifted most of it went out of the passband of my CCD so it is very faint. A z of 3.4 means the wavelength of each spectral line is 4.4 times longer than it was when emitted. Shifting Ultra violet into the infrared part of the spectrum. Also while it was only 5 billion light-years from us when its light was emitted those 11.88 billion years ago, the light had to travel those extra 6.8 billion years thanks to the ever-expanding universe. In those 11.88 billion years it has been moving away from us at an ever-increasing speed and is now some 22.5 billion light-years away. So the expansion of the universe has carried it 17.5 billion light-years in 11.9 billion years. Yes, the universe can and does expand faster than the speed of light. That means the light it emits today (if it even exists today) will never reach us. The fact the universe was much smaller 11.88 billion years ago than it was when the other quasar's light left it plus this faster than light expansion plus relativity issues create the very counter-intuitive situation that the quasar we now see 11.55 billion years later was 5.3 billion light-years distant when its light left. Yes, it was further away but its light got here quicker as it didn't have as far to go through the ever-expanding universe. These figures are using NED's 5 year WMAP calculator. I didn't do the math, NED did it. You can enter your own parameters and rerun the calculations if you don't like this result. Now, where's the Jack Daniels when I need it?

Arp's image with the 200" Palomar telescope (north to the left)
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp163.jpeg

The HST image of the core region can be seen at:
http://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/NGC_4670.jpg/622px-NGC_4670.jpg
I don't know who assembled it from images at the Hubble Legacy Archive site. North is to the lower right corner.

14" LX200R @ f/10, L=4x10x2' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP163

ARP164

Arp 164/NGC 455 is a merger remnant in Pisces some 250 million light-years distant. Arp put it in his category for galaxies with diffuse elements. It appears these diffuse elements are looping tidal trails of stars ripped from the merging galaxy showing the path of the merging galaxy as it was torn apart orbiting the larger galaxy. The NGC Project classifies it simply as peculiar. NED says S?. It likely will settle down to become an elliptical galaxy. It was discovered by Albert Marth on October 27, 1864.

The field seems to contain a few galaxies with the somewhat closer redshift of about 210 million light-years, two of which are in the image. A couple others are just outside it. Is Arp 164 related to these? It seems likely they are. NED has little data on this field. Only a few galaxies in my image are in NED's database and most have no redshift data. All galaxies NED catalogs are shown in the annotated image. A question mark is used for the distance of most since they don't have any redshift data. Those without any catalog entry and therefore left blank on the annotated image are apparently anonymous.

I wasn't going to prepare an annotated image but then 9 asteroids showed up in the image (actually more but many didn't survive the processing). Within 20 minutes of Arp 164, the minor planet center showed 18 asteroids down to magnitude 21 which was my limit at the rate these were moving. The 9 that survived the color combine are:

(180762) 2004 PC14 magnitude 19.3
(105898) 2000 SC188 magnitude 18.5
2007 VJ230 magnitude 19.5
(256661) 2007 XD22 magnitude 20.1
2010 TH124 magnitude 20.2
(102564) 1999 UH30 magnitude 19.9
(279746) 1998 MK6 magnitude 20.6
2010 TC159 magnitude 20.9
(251674) 1995 SP22 magnitude 20.5

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp164.jpeg

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

Related Designations for ARP164

ARP165

Arp 165/NGC2418. A very large galaxy some 240 million light-years away. It is located on the eastern edge of Gemini. Arp 165 is classed as an elliptical peculiar galaxy. It has one low contrast blue arm against what otherwise is a galaxy that looks much like a typical elliptical, until you notice the odd tidal extension on the side opposite the blue arm. Arp classed it under "Galaxies (not classifiable as S(piral) or E(lliptical); with diffuse elements. This seems rather appropriate. It appears there has been very little study of this galaxy as I could find little on it. There are a couple small galaxies right near it (north) but I found no redshift data on them so can't tell if they are really companions or just apparent ones due to line of sight. One paper did call them companions but did so in a way that didn't indicate if the author considered them actual companions. In fact only one other galaxy in the entire field had any distance data I could find. That is CGCG 087-015, toward the upper right corner of my image at about the same distance as Arp 165. It is very blue but otherwise, shows no sign of interacting with Arp 165. To the lower left of Arp 165 is a pair of galaxies that could be interacting, PGC 3090318/17 left to right. Since this was written a few more galaxies now have redshift data. Including this pair that have the same redshift but it was determined photographically apparently using the combined colors of both galaxies under the assumption they were at the same distance. Thus it is still debatable if these two are interacting. I think they are but this doesn't prove it as far as I'm concerned. Arp 165/NGC 2418 was discovered by Édouard Stephan on January 23, 1874.

5 asteroids are in the image. See the annotated image for details.

Arp's image with the 200" Palomar telescope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/arp165.gif
Seeing was poor on Palomar mountain when he took this image. The above link is to the small version. Here's the large one but it shows no more detail, at least on my monitor.
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp165.jpeg

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

Related Designations for ARP165