This triggered several Astronomy Cast listeners to write and basically say “Huh?” We addressed this a little bit in today’s questions show (real show to follow tomorrow or Wednesday – we had problems with a corrupt audio file over the weekend and got behind). I wasn’t able to give as thoughtful a response in the show as I might have liked however, so I’m going to try and write something here.

So, first, I’d like to say there are two ways to look at this: 1) In reality, 2) in make-believe land.

Make-believe land is oh so much more fun. So, lets imagine that somehow we are able to grow a very large blackhole in isolation. Then, using imaginary technology (we are in fantasy land, afterall), we throw a star at the supermassive blackhole (SMBH) so that it’s goes on a straight, uninterrupted path toward the SMBH. So straight, so perfect, infact, that if we could watch we’d see it hit on a line connecting the star’s center of mass with the SMBH’s center of mass. Now, the SMBH will simply slurp up this perfectly thrown star. Burp. No more star and no accretion disk. Now, If you, using your super duper, impossible, imaginary technology could throw a star with dead on aim over and over every second across all the epochs of time, you could pretty much build a SMBH as big as you wanted.

Here is where I stress this pretty much can not happen.

Let’s look at the reason’s briefly. First of all, the only way to easily get a SMBH all by itself is to have three galaxies merge together and one of the SMBH’s in the merging system gets ejected via three body interactions. (Pretty much any three body interaction between objects of similar masses leads to one of the masses getting spit out. This works for stars and black holes). So now I have an isolated SMBH hurtling itself through the intergalactic medium, passing rapidly through the space between galaxies. Yes, I can get a SMBH all by itself, but now I kind of have it hurtling through space.

So let’s image it lands in a nice friendly crowd of stars. As it hurtles in  through the stellar populations, stars will fall in from all sides, spiraling in and forming a disk. At the same time, any dust and gas that may be around will also get sucked in. Eventually, a thick disk of material from this thick pocket of stuff will form a nice hot disk that give off so much light and wind that anything new trying to fall in will simply get blown away before it can get so close that it can’t escape.

And it’s not like there is a lot of stuff to eat in this imaginary star cluster we have flung our imaginary SMBH into.

The reality of the universe is in many ways far more interesting then our imaginary scenerio and galaxies self-regulate the size of supermassive black holes through complex feedback mechanisms. In the rather cool paper mentioned above, astronomers Priyamvada Natarajan and Ezequiel Treister describe how a combination of winds and star formation regulate the size to which SMBHs can grow. They estimate the upper limit is roughly 10^10 Solar masses (10,000,000,000 Solar Masses).

Here’s how it works:

First of all, most galaxies just don’t have enough stuff around them to ever grow that big, and as the universe expands and carries non-gravitationally bound systems farther and farther apart, the potential for truly giant SMBH’s dimishes.

Second, while it is possible to grow what they term Ultra-Massive Black Holes, SMBH’s approximately the size of the 10^10 Solar Mass upper limit, it is hard to grow them bigger. These objects when they do exist, are in the hearts of cD galaxies sitting in the centers of large galaxy clusters. In these systems, the gas the SMBH can consum eventually gets pushed away when the luminosity of the accreting material reaches a certain threshold. Once the gas is pushed away, it really has no reason to fall back to the center and get eaten later unless something disturbs its orbit, and if that does happen, it will get pushed away again as soon as the accrestion luminosity again gets above a certain level.

In addition to clearing out dust and gas that isn’t currently trying to flow in, but happens to be local, this accretion luminosity can also actually stop material that is in the process of falling in already (stuff that hasn’t gotten to the event horizon yet). It’s all about how the kinetic energy of the infalling material is changed.

Finally, the growth of the SMBH into an UMBH also means that any outflow from the black hole will be bigger and badder. In general, the material flowing away from SMBH’s flows out, cools, and some of it condenses into stars or flows back in as accretion. Once the outflow get’s big enough, it becomes a superwind and no recycling of material takes place – bye  bye gas.

So, in our reality, black holes have an upper limit that comes basically from the fact that things spiral in and the material spiralling in does destructive things: Blasting Light, Blasting Wind. Blame angular momentum and if you want to build a bigger blackhole, get good at aiming stars.

I have to admit, there is a soft spot in my heart for conference proceedings. Once upon a time, when you wanted to quickly dive into a new area of astronomy you went to the university or observatory library and searched out the ASP or IAU conference proceedings on the topic of your passion, and then wandered off to read it cover-to-cover. As an undergrad, I got my introduction to pulsating variable stars that way, and in graduate school I am guilty of losing 4 cloudy nights of my life to a periodical on cataclysmic variable stars for no particularly good reason. Today, I teach at a small college that doesn’t have astronomy conference proceedings in its library, so when I want to get my fill of something new, I either have to fork over the cash, or wait on arXiv for something new and exciting to appear in a burst of related papers. One such burst is currently unfolding, and the topic is the Large and Small Magellanic Clouds. Back in late July there was an IAU symposium on these two nearby systems.

The Large and Small Magellanic Clouds are a pair of nearby irregular galaxies that everyone thought were orbiting the Milky Way galaxy in a death spiral. The way it was taught, these two systems, visible to the naked eye in the Southern Hemisphere, are orbiting the Milky Way. as they go they appear to be leaving behind a faint trail of material as they go, like a slug’s train across the sidewalk. According to the story, they are a binary pair, with the Small Magellanic Cloud orbiting the Large on a nearly circular orbit. It is/was believed that the two systems collided about 200 or 300 Myr ago, triggering star formation and maybe even causing the 30 Doradus (Tarantula Nebula) star forming reason to form.

This is the standard story. Heck, I’ve told this story several times on Astronomy Cast even.

The thing is, we’re not entirely convinced it is true.

Back in 2006, a team of astronomers lead by Nitya Kallivayalil published Hubble Space Telescope observations that seemed to indicate that these two galaxies are actually just passing through. According to their measurements, the galaxies are moving tangentially at 370 km/s relative to the Milky Way, which is 100 km/s faster than we thought and also fast enough that they should just keep going, moving past the Milky Way on their journey through the Local Group of galaxies (which they shouldn’t leave – they are gravitationally bound to the group.) This measurement was the final word on the matter – The authors acknowledge that more data is needed, and they even tried to get that data with Hubble’s high resolution ACS camera, but it failed, and they couldn’t do the follow up that was needed. So, while they wait for Hubble to get repaired, they did the next best thing – They reanalyzed their data looking for every possible error they could have made. It turns out that it still looks like the LMC and SMC are just sweeping by.

This has some rather serious effects on our understanding of several observations. First of all, there is a stream of material that is “connected” on the sky to the two galaxies. This material is referred to as the Magellanic Stream, and it was thought that it was made of material gravitationally torn off the systems. We refer to this as a tidal tail. The catch is, tidal tails typically don’t form with so much vigor during a pair (or in this case a trio) of galaxies’ first encounter. The location of the Magellanic Stream is also wrong, given our new understanding of the galaxies motions. And it also looks like the Small Magellanic Cloud can’t be orbiting the way we thought either.

Since 2006, astronomers have been working hard to try and solve these problems, and at IAU Symposium #256, they met at Keele University to sort out some answers.

The first big problem is the Magellanic Stream. Using some very pretty models, a paper by Besla et al shows that this string of material could have been created through interactions between the dark matter halo and regular matter halo of the Milky Way Galaxy and a former disk of gas (an extended HI disk) around the LMC. If the LMC has once had a disk of material around it and the disk hit the Milky Way at the right angle, a process called Ram Pressure Stripping could have stripped off the disk to create the Magellanic Stream.

One problem down.

The next problem is trying to figure out how the Large and Small Magellanic Clouds are orbiting one another. This can be done by looking at what types of orbits could be stable. In computer models, it looks like the Small Magellanic Cloud may simply be on a highly elliptic orbit around the Large Magellanic Cloud, and that orbit maybe slowly getting smaller.

Second problem down.

And put together we have a new understanding. It now appears we are seeing these two binary galaxies as they slowly spiral together, and they just happen to be passing by us as they engage in a death match of sorts.

As was stated at the top, these results still need more followup observations. They need the Hubble to be fixed. But this will come. Soon. Sometime in the next several weeks hopefully.

In case you haven’t seen this yet, let me share the most amazing image of two Shuttle’s lined up waiting for launch. The foreground craft, Atlantis, will be going up to the Hubble Space Telescope to install new instruments, repair the old, and service several parts, including gyroscopes used to control its pointing. But that’s a story for another post.

Atlantis and Endeavour on pads 39 A and B. Credit: NASA

This is scientifically a wonderful thing: Being able to understand what a black hole that is actively feeding looks like as a function of feeding rate and angle of view allows us to say something based on the physics of the system, where as having a bunch of names associated with a bunch of different images is more like leaf collecting without taking DNA samples. Being able to understand how an icy object looks in the solar system both when it is out near Pluto, and when it is making a plunge past the Sun allows us to see how materials get distributed through the solar system. The more we learn, the more we see everything can be broken down into a series of fewer and fewer large boxes.

It is unfortunate, however, that our understanding didn’t come before we had a chance to come up with 40 million names for what we now know are related objects. For instance, all of the following objects are active galactic nuclei: QSOs, Qausars, Seyfert 1s, Seyfert 2s, BL Lac objects, Blazers, and LINERs. Similarly, novae, dwarf novae, classic novae, recurrent novae, Z Cam objects, U Gem objects, and SU Urs objects are all types of cataclysmic variables. The journey to our understanding was a long one, and it came by bringing together many small groups of objects, one at a time, and seeing that at their core they are all the same.

What we are realizing there is a taxonomy of the sky. Just as I am a [mammal, primate, hominid, homo sapiens], a star system might be [binary, cataclysmic variable, U Gem object].

But while we have a clear and agreed upon language for discussing the names of biologicals, such a precise language doesn’t yet exist in astronomy. If I want to find all the latest papers on galaxies with actively feeding supermassive black holes that have observable broad and narrow line absorption regions and tiny little radio jets, I need to search on the terms active galaxy, radio galaxy, Seyfert 1, and active supermassive black hole. This lack of precision in language slows the progress of research. One team may make huge strides, developing their own methods and vocabulary and publishing in one set of journals with one set of keywords, while another group makes parallel and complementary progress, developing different methods and vocabulary while publishing in a different set of journals with another set of keywords. If the teams don’t happen to meet at a conference or have someone point out one another’s work, it could be a couple years into the research before they realize they are doing something that would greatly benefit from collaboration.

As our ideas are unifying we need to take care to unify our language as well. We need to take care to use all appropriate keywords and not be lazy as we check boxes, and we need to take the time to do literature searches on every possible archaic turn of language as well. Even though we now know Andromeda is a galaxy (really, it is), there are those that still call it the Andromeda Nebula. It won’t be easy to change our language habits, but it will be good for the soul (or at least good for those of us doing literature searches) if we can find a way to manage it.

The universe is a deadly place. (Don’t believe me? Pre-order Phil’s book!) And apparently, if you’re a galaxy, you simply have to learn how to live with abuse unless you are lucky enough to live in isolation

As we look out across the sky, we find that galaxies like people prefer not to be alone. Studies by determined scientists like Martha Haynes have found that if you look hard enough, their are large galaxies like our own with no nearby large companions, but finding these systems is hard. It is much easier to turn up pairs, groups, and clusters of all sizes and shapes – these communities of galaxies seem to be the more normal social structure for these organisms of stars and gas. But not all family units are healthy ones. In small groups, like the one our Milky Way is located within, it is possible to see active star formation and beautiful spiral structure as far back in time as we are capable of resolving structure. In these small systems, the large galaxies dance lazily, and it may be billions of years before the largest members sweep out their arms to embrace one another in a dance of death. Sadly, that deadly gravitational embrace seems to be the natural way for all galactic relationships to end.

In the largest systems – the Coma and Virgo clusters of space and time – this process is accelerated. There is more mass and thus more gravitational pull, and galaxies whip through space at higher velocities, and due to the increased density – the larger number of galaxies per volume of space – the probability of collisions and gravitational interactions is much higher. This basically means death comes earlier to galaxies that choose to live in cosmic cities.

This death can take many forms, but to understand it, we must first understand how giant galaxies are constructed.

Everything we think we understand about modern galaxy formation* is built on a simply picture: Small systems gravitationally fall together via a process known as Hierarchical Galaxy Formation. As they merge, these small systems build giant spiral galaxies. These large systems will continue to happily consume small systems while calmly producing stars for billions of years at a time.

As these giant galaxies live out their cannibalistic, baby-galaxy-eating lives, they leave little evidence of their feeding. Occasionally, there will be a warped disk or a tidal tail (or both), but generally they are good about gravitationally picking up their own messes. As small galaxies fall into larger galaxies, they are tidally disrupted. This means the difference in gravitational pull on one edge of the small galaxy is significantly different than on the other edge, such that the difference in pull generated by some external force (for instance a big galaxy) is greater than the galaxies self-gravity (the force that holds it together). This is the moral equivalent of pulling on the front edge of a cake with enough enough force to pull the cake apart. It is possible to pull on the cake just enough to just move it, but if your pull is greater than the pull of the molecular bonds inside the cake, you will break the bonds and also break the cake.

In the image at left, there is an amazing loop of excess stars surrounding the main (seen edge-on) disk galaxy. This system, called NGC 5907, is an isolated spiral that has recently consumed a smaller galaxy. As the galaxy orbited in and fell apart, it left behind a train of stars, and evidence of its death in the form of a warped disk. The stream of stars is technically referred to as a tidal tail. (image credit:David Martínez-Delgado ( IAC, MPIA), Jorge Peñarrubia (Univ.Victoria ), R. Jay GaBany (Blackbird Observatory), Ignacio Trujillo ( IAC), Steven R. Majewski (Univ. Virginia), Michael Pohlen (Cardiff)).

In addition to tidal tails, interactions between large spirals and smaller systems can lead to fascinating features, varying from grand design spiral arms (like in M51), to bars (like in NGC 1300), to star bursting rings (like in NGC 4314). These interactions do not destroy the large galaxy’s structure, but rather enhance it by changing the gravitational field.

Changing a spiral into something new requires bigger interaction.

Shaping changing events can come in many forms. Most familiar are the head on collisions of merging galaxies, such as the mice (shown at right. Image credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA). These dramatic events initially trigger massive star formation, as pockets of gas and dust are shocked into collapse and driven toward the system centers. What dust isn’t converted into stars in typically jettisoned as beautiful tails and twisted arms. As the galaxies merge into a single object, their spiral structure is destroyed, and a new elliptical shape takes hold. Once the breathtaking burst of star formation is over and the tidal arms are lost, the systems fad away over billions of years into a single dead red elliptical galaxy. This is the eventual fate of the Milky Way and its nearest companion Andromeda.

In large groups, not all interactions are as straight-forward. Often, death comes from a dozen off center blows.

As a spiral galaxy falls into a large cluster of galaxies, it experiences many traumas. It is shocked as it slams into the inter cluster medium. The diffuse gas, which is extremely hot in the cores of clusters, used to be part of the cluster’s member galaxies. Over time, gravitational interactions stripped this material out of its parent systems and left it orphaned in the space between galaxies. Gravitationally trapped, it is heated both through the processes you learn about in high school chemistry (combine enough moles of a gas in a given volume under sufficient pressure, and it heats up. In this case, the pressure comes from gravity compressing the gas), and also from more exotic means, such as radio galaxies blasting the inter cluster medium with high energy jets. The shock of systems colliding also heats the gas. Put together, all these pieces can bring this gas to as much as 100,000,000 degrees Celsius! This angry hot gas is just waiting to do bad things to infalling spiral galaxies. As these spirals fall in, the shock of hitting the gas can trigger star formation, and also disrupt the shape of the galaxy. This is called ram pressure stripping, and it is most destructive in cluster cores. If it blasts too much gas from the infalling galaxy, it can effectively strangle all future star formation, killing off the system.

In addition to being shocked by the inter cluster medium, our in falling spiral may also interact with other galaxies. When galaxies approach each other slowly, such as with the Andromeda and Milky Way, it is possible for them to gravitationally grab onto one another and merge. If instead, two galaxies zip past each other at high velocities, their mutual gravitational attraction will disrupt the systems, but will not cause them to merge. Over time, multiple high speed encounters can transform a spiral galaxy into dwarf elliptical or S0 system. In the most dense clusters, these interactions may occur as frequently as once per billion years. Over just the past 4 billion years, moderate sized galaxy clusters have successfully transformed blue, star bursting spiral galaxies into dead ellipticals via galaxy harassment.

Looking across the universe, we see a pattern where the smallest systems, like the one we live in, have star formation across all epochs, while the richest systems are dead and red no matter how far back we look. It is in the middle-sized systems that we see the universe evolve. This picture is defined by gravity. The large systems formed first, died quickly, and are so dense that infalling galaxies are killed off in as little as 10,000,000 years by ram pressure stripping. What the ram pressure doesn’t kill, galaxy harassment takes care of. In the smaller systems, galaxies move more slowly, generally don’t lose significant amounts of gas, and take their own sweet time getting around to merging. In the middle, something in between occurs, and we are able to see the transformation from clusters having as much as 50 percent blue galaxies, to similar systems only containing a few percent (if that many) blue galaxies over several billion years. Blue means star formation. As the blue galaxies go away, the entire system is said to die.

I have to admit that the beauty of the galaxies, coupled with my own awe at our ability to understand what is going on leaves me wishing we had chosen less violent metaphors to describe our science. Galaxy mergers are one of the most stunning things we can image. While the process does involve the collision of a lot of gas and dust, and it does bring an end to spiral structures, it also causes the birth of something new: an elliptical galaxy. Still, violence is how we are accustomed to emotionally viewing all interactions that involve sudden shape change, or removal of bits. We have been taught, when you see a car fly into another car such that they turn into a single hunk of metal (minus several dozen small bits) you are are seeing something violent, destructive, dangerous, and deadly. When I look at the universe, I see something magnificent, stunning, violent, destructive, dangerous, and deadly. We have no working metaphor of beauty for this type of process. Our language is simply insufficient to capture the glory of the cosmos, so instead, we tell a story of violence. After all, if it bleeds it leads, and the universe is nothing if not deadly.

*Some large galaxies likely formed via a different mechanism in the early universe.

I’m not sure what it says about the personalities of those of us who study galaxy clusters that these are the words we have chosen as a community to use, but I would love to work with a sociologist focused on linguistics to learn more.

Using the INTEGRAL satellite, astronomers discovered 20 new binary systems that consist on neutron stars orbiting supergiant stars. These findings were presented by Dr. Sylvain Chaty (University Paris 7 / Service d’Astrophysique) at the first GLAST Symposium in Palo Alto, California. Using multi-wavelength observations, he and his team identified 20 sources of X-Ray light, and then did followup observations in optical and infrared light using ESO facilities (image above, credit: Paris 7). The IR and optical observations showed that the X-Rays originated from neutron stars passing through clouds of material surrounding super giant stars. The super giant stars 30 times the mass and 20 times the radius of the sun, and are at a stage in their life when they are puffing off roughly one Earth mass of material per year. This material forms a circumstellar cloud around the supergiant that blocks the majority of the giant stars light from reaching us here on Earth. Instead of a giant star, what we see is a cloud of hot dust and gas radiating in the infrared. (all warm things – including human readers of this blog – emit thermal energy in the form of infrared light). When a neutron star enters this gas cloud, its extreme gravity compresses and heats the gas around it until the material emits X-Ray light. In some of the observed systems, the neutron star’s entire orbit keeps it within the gas and dust cloud. In other systems, the neutron star’s orbit is shaped more like the orbit of a comet, and it spends some of its time in the cloud emitting X-Rays, and other time outside of the cloud. There is a really neat movie of this available on Chaty’s website.

In a second announcement at the same GLAST Symposium, a team of astronomers who operate the High Energy Stereoscopic System (HESS) in Namibia described how gamma-ray light can now be convincingly associated with star forming regions that contain massive young stars. These stars, Wolf-Rayet stars, are some of the highest mass stars known, and they live very short lives that are punctuated with a supernova burst and the formation of a black hole or neutron star. The HESS team found diffuse X-Ray emission surrounding a binary system of two Wolf-Rayet Stars. This system is the highest mass binary system known. The diffuse gamma rays come from an area roughly 28 pc in diameter – these is several 1000 times greater than the separation between the two stars! They suggest that the gamma-ray emission may be created by when accelerated particles from the high-energy region around the binary interacting with slower moving materials from the star forming region surrounding the binary. In this scenario, the binary Wolf-Rayet stars blow open a blister in the star forming region in which they reside. Particles within these region are shocked and accelerated. At the skin of the blister, surrounding material is able to leak in, and when it collides with the higher energy particles it is shocked into emitting gamma rays. This scenario has theorized for for a long time and was detailed in 1997 by Whiteoak and Uchida, but this is the first time all the pieces – gamma rays, Wolf-Rayet stars, and a star forming region – have all been found together.

So, what about the lobster? Currently we live during a period biologists refer to as the Holocene extinction. This is an extinction event that is largely driven by man. As we eat things, build things, and chemically treat thing we are killing off vast numbers of animals. It (may have) started with the wooly mammoth, a favorite cuisine of early man, and it continues today with sharks, sword fish, and modern elephants. I could continue my “We’re killing our planet” tirade, but others do it more effectively (see here, here, and here). So, back to the lobster. In a world where so many species are dieing off, it is really cool to find a new type of lobster, and indications that in the Philippines there may be 1000s of new critters just waiting to be classified. And, on a morbid note, each critter we find is one more critter whose genetic structure we can collect and save. Several groups have suggested DNA should be collected from as many life-forms on earth as possible so our planet can someday be re-populated with lost species. Admittedly, this would require cloning, and science still doesn’t know how to clone things consistently, but . . . You can’t clone species you don’t have dna for, so, I’m all for freezing genetic samples.

So, another day, another addition of species not covered in a text book that increase the diversity of our universe. Go science, go.

So, why should any one care? Well, quasars are giant black holes in the process of feeding on gas and dust (and maybe even stars and planets) that just happen to get too close). By giant black holes, I mean black holes that are hundreds of thousands to tens of billions of times larger than the Sun. And, by feeding, I mean they are chowing on solar system masses worth of gas and dust with each bite, and sometimes spraying jets off high-energy particles while giving off light in ways that make these things the brightest shining actors in the entire universe. One quasar is just cool, and getting three cool things together all at once is, well, something that naturally attracts the observational astronomy paparazzi (or atleast grad students seeking projets).

More scientifically, we have a lot of theories on how galaxies form and grow from the start of time to today. These theories indicate that galaxy mergers and quasar activity were both more prevalent in the past, with the epoch of quasars peaking around a redshift of z = 2, when the universe was just 2 billion years old. While we’re still working to understand the physics of quasars, it seems that quasar activity is related to galaxy-galaxy interactions, and galaxy interactions should occur in large numbers at similar times. Thus, theoretically, if you are going to find interacting systems of QSOs, it makes sense that you find them somewhere near z = 2. This triple system was found at z = 2.076, matching that theory.

This system, QQQ 1432-0106, was initially identified as a potential double quasar gravitational lens. This means, it was identified as a system where a single distant quasar had its light bent by an intervening massive object such that it appeared as two objects rather than one. This is a common effect, with quasars being found split into as many as 5 different apparent objects (You can read more aboutthis effect here. Additional observations of these two objects, however, turned up a third object, and gravitational lensing models cannot replicate these observed pattern of three objects and their luminosities. The luminosity ratios of the quasars are 1: 25 : 200. This, in non-straight forward ways, reflects differences in mass, with the brightest system being approximately billions of solar masses and the second brightest being hundreds of millions of solar masses.

Spectroscopic observations of these systems give additional evidence that these are three physically related objects instead of a gravitational lensed single object. While all three systems have similar emission lines and appear at the exact same redshift, there are minor differences in the spectra that indicate slightly different distributions of material are present in the three systems.

Our current understanding describes this as a system consisting of three physically related interacting quasars that will eventually merge together. A possibly disturbed galaxy is visible around the brightest of these three quasars. The supermassive black holes in their cores – the angry monsters that power the quasar light – will interact in ways that may result in one or more of the supermassive black holes. This theory-based result has interesting implications. It is possible that there are free-roaming supermassive black holes wandering the universe, periodically consuming intra-galactic dust and gas. It also raises questions on how today’s galaxies end up with central supermassive black holes that have sizes directly related to the characteristics of the parent galaxies. This time, theory leaves us in a place without a lot of observational evidence to support us. To verify our concepts, astronomers need to identify galaxies lacking supermassive black holes, galaxies with supermassive black holes of unusual size (too small, rather than too large like ROUS*), or catch a system in the process of ejecting central black holes during merger. (for neat animations, see This Site.)

So, at the end of the day, some theories have added evidence, and some theories leave us asking questions, but no matter what, the quasars are spectactular and the science in this bit of observing is solid. This is a case of good science, done right, going through the scientific process to correct false starts and firmly establish this as the first gravitational interacting three quasar system. Kudos to George Djorgovski (CalTech) and his team for a job well done.

*Rodents of Unusual Size, from the Princess Bride