Astronomers often encounter phenomena in their observations that are not only difficult to explain, but simply impossible to describe. The further we look into space, the more such phenomena we find. We suggest that you familiarize yourself with a dozen of some of the most interesting galactic phenomena and oddities collected over the years of painstaking contemplation of space.
Triangulum II Galaxy
The Triangulum II galaxy located near the edge of the Milky Way has already amazed many astronomers with its incredibly fast stars. Our tiny galactic neighbor contains a record small number of them - only about 1000 (in the Milky Way, for example, there are 100 billion). However, a colossal mass lurks in Triangulum II.
While observing this galaxy, the Keck Large Telescope, located on the Mauna Kea volcano in Hawaii, observed six stars moving much faster than expected. The fact is that the galaxy is so dark that only these six stars were visible through the telescope. However, even thanks to these stars, the researchers were able to calculate the gravitational forces of Triangulum II and its total mass. It turned out that the galaxy is more massive than the combined mass of all its stars.
Scientists have found that this galaxy contains the highest concentration of dark matter among all galaxies studied before. Nevertheless, French astronomers from the University of Strasbourg believe that the reason for such a strong scattering of stars and the dimness of the galaxy is the effect of the gravitational forces of the galaxies adjacent to Triangulum II.
Such a high concentration of dark matter in Triangulum II gives scientists a direct opportunity to try to study this strange substance, which accounts for 24 percent of the total mass of the universe. Due to the fact that this galaxy contains very few stars, it produces virtually no gamma radiation, thus giving the chance to detect X-ray forces from the interaction of dark matter. Since the galaxy is virtually dead, these signals should be recorded clearly, with little or no distortion from the multitude of cosmic energy sources present in more "lively" areas.
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Mysterious galactic ring
American and Hungarian astronomers recently stumbled upon a structure in space that turned out to be so huge that it is difficult to believe in its existence. This structure turned out to be a cluster of galaxies that formed a kind of ring that stretches for almost 5 billion light years. This object is so huge that in the night sky in the optical range, it would look 70 times larger than the full disk of the moon.
Astronomers were able to calculate the estimated size of this cosmic ring due to the similarity of the seven observed bursts of gamma radiation - one of the largest phenomena of the release of explosive energy in space. Gamma-ray bursts typically occur when a star goes into super-bright supernova and then turns into a black hole.
Since the observed bursts were practically at the same distance from each other, astronomers assumed that they were part of the same cosmic megastructure. Of course, it is not worth discarding the probability of chance either. The existence of a galactic ring of this size contradicts our cosmological models, which describe the size limit for the largest objects in the universe, which, according to these models, is about 1.2 billion light years.
And even if this ring does exist, why is it so big? Nobody knows the answer to this question yet. However, there are suggestions that the same mysterious dark matter is somehow responsible for the creation of such space objects of incredible size.
Tayna Galaxy
By combining the power of the Hubble and Spitzer space telescopes, astronomers have discovered one of the most distant objects in the universe. At the same time, scientists believe that this object appeared only 400 million years after the Big Bang. That is, it is also one of the oldest objects in the Universe. This object is a barely noticeable and extremely faded galaxy called Tayna, which means "firstborn" in South American dialect. So far, scientists have discovered 22 of these "first-born" galaxies, originating shortly after the Big Bang.
It took the power of two of mankind's best space telescopes to find the Tayna galaxy, and a lot of help from the galaxy cluster MACS J0416.1-2403, located about four billion light-years away. With a mass of a quadrillion Suns, this galaxy cluster pulls in an incredible amount of light, creating a gravitational lens and allowing a view of Tayna, which is essentially behind it. The James Webb Telescope, set to be sent into space in 2018, will give us a better view of this galaxy and provide much more detail about this representative of the first galactic objects in the universe.
Galactic nanny
Astronomers are not entirely sure of their knowledge of how galaxies are born. It is generally accepted that galaxies take all the necessary matter for their formation from the intergalactic environment. However, there are other assumptions. According to one of them, the initial formation of a galaxy occurs from a dense accumulation of dark matter, around which clouds of hydrogen and other gases begin to accumulate, attracted by gravitational forces. Another theory is that galaxies are formed from matter from a specific source. The first option is too long to be verified from observational data. No one ever watched the second.
At least until recently. Researchers at the California Institute of Technology using the Cosmic Web Imager instrument mounted on the Hale Telescope at Palomar Observatory have discovered a protogalactic disk (a very young, just forming galaxy) located 10 billion light-years away. It consists of hot gas, the volume of which is increased by the cold gas that the young galaxy receives from the filament of the so-called Cosmic Web, next to which the galaxy is forming. Scientists believe that this is the first direct evidence of the existence of the Cosmic Web, which unites everything in the universe.
Due to the fortuitous placement of two quasars in this region of space, part of the spider web that feeds gas to the newly formed galaxy has heated up, allowing scientists to determine its presence.
Big Magellanic outrage
The Large Magellanic Cloud (LMC) and its dwarf companion, the Small Magellanic Cloud (MMO), are our closest neighboring galaxies, located approximately 160,000 and 200,000 light years away. As the largest dwarf galaxies near the Milky Way, they can be easily seen in the southern hemisphere of the night sky.
Scientists note that something strange is happening with the LMC. In the Tarantula Nebula, part of the LMC, astronomers have discovered a veritable incubator of star formation. But, as it turned out, much less stars are formed here than it seems at first glance.
The fact is that about 5 percent of the 5900 studied large and very large stars located in the LMC do not belong to this galaxy. BMO actually stole them from MMO. Scientists came to this conclusion after they discovered that these stars turn in the opposite direction, compared to the rest. Moreover, the chemical composition of these stars is not at all similar to that which is usually characteristic of LMC stars. These stars contain much more heavy elements such as iron and calcium. Scientists believe that such a fertility of the Tarantula Nebula is due precisely to the fact that the LMC steals stars from the IMO. In addition, BMO does not hesitate to eat up gas from its space neighbor. In this case, the gas accelerates so strongly that it "ignites" the residual gases between the two galaxies.
Galaxy Hercules A
At the center of the galaxy Hercules A (3C 348) is a giant black hole with a mass of 2.5 billion Suns! It is 1,000 times more massive than the Milky Way's black hole and produces two giant jets of plasma that darken virtually the entire galaxy in which they are located. Moreover, spreading over 1.5 million light years, these streams of plasma obscure other galaxies, including the Milky Way, which is 15 times smaller in diameter. The amount of energy found here is very difficult to describe. The output recoil of a black hole in the center in the equivalent of radio waves is one billion times higher than that of our Sun.
This is enough to make Hercules A one of the brightest sources of radio waves ever observed. The pink-red beam in the image above is a plasma of atomic particles and magnetic fields accelerated to relativistic speeds (almost the speed of light). Bulky globular clusters along the edges most likely indicate many early, incredible outbursts.
Unfortunately, all this is invisible to the naked eye, that is, it is only a representation of the artist. The image was created on the basis of optical data from the Wide Field Camera 3 of the Hubble telescope, as well as observations of the Very Large Array radio telescope (Super Large Antenna Array).
Ancient white dwarfs of the Milky Way
Our galaxy is very ancient. It is almost as old as the universe itself. Observing the central bar of the Milky Way, astronomers have discovered a cluster of 70 white dwarfs - dense and compact stars with a mass of the Sun (or even more), but not larger than the Earth.
Of course, there are many more stars in the bar, but scientists were interested in a specific group located in relative openness to cosmic dust and located about 25,000 light-years from Earth.
Now these stars are nothing more than astronomical relics, however, according to scientists, they can tell us about how our galaxy appeared. Some white dwarfs are believed to be over 12 billion years old. In addition, scientists think that these white dwarfs were among those stars that once "seeded" our galaxy. The history of the Milky Way began with them. Millions of stars that have completed their life cycle have followed suit, scattering their matter 100,000 light years away.
An incredibly bright galaxy
NASA's WISE Space Telescope has discovered the brightest galaxy ever found. Its brightness is equivalent to that of over 300 trillion suns. The photons of the galaxy WISE J224607.57-052635.0 in question had to travel 12.5 billion years to leave us their message and give us an idea of what the universe actually looked like at the dawn of its birth.
This galaxy is so bright that it is difficult even to look at its full image in the artist's view, which can be seen above. However, it owes its brightness not at all to the stars. The galaxy is so bright because of its black hole. It is so massive that it even casts doubt on our understanding of physics to some extent.
Scientists are surprised that the early universe could have been a haven for such space objects. Usually black holes are limited in their "gluttony", and the past time would not be enough for it to swallow the entire galaxy. However, this black hole was able to somehow overcome the "limit of its voracity" several times, until it reached the mass that it has now. She has "gorged himself" so much that now she releases (regurgitates) a gigantic amount of energy, which literally hits the gigantic cocoon of gas located here, which eventually begins to illuminate with a dazzling aura.
A tiny galaxy with a giant black hole
The ultracompact dwarf galaxy M60-UCD1 could change our understanding of black holes and the concept of dwarf galaxies in general. It is only 300 light years across, which is only 0.2 percent of the size of the Milky Way. However, this galaxy contains a black hole with a mass equivalent to 21 million suns. For comparison, the black hole at the center of the Milky Way is much larger in size, but has a mass of only 4 million Suns.
Until recently, it was believed that the size of galaxies and the size of black holes are interrelated. However, this discovery challenged this model and suggests that the sizes of these two space objects may be completely incommensurable. And scientists have an explanation for this.
The fact is that M60-UCD1 was not always a dwarf galaxy. Astronomers from the University of Utah (USA) believe that this galaxy was once home to 10 billion stars. However, she got too close to her larger galactic neighbor, which actually robbed her. As a result, only about 140 million stars remain in the galaxy. This makes M60-UCD1 ultimately one of the smallest galaxies with a massive black hole at its center. However, the same assumption of scientists prompts other questions. Are dwarf galaxies "failed" large galaxies, or have they all fallen victim to their larger neighbors at some point in their history?
Galaxy EGS8p7
The 13.2 billion-year-old EGS8p7 galaxy is so ancient that we shouldn't see it. After the Big Bang, the universe was for some time a hot cluster of protons and electrons. After a cooling period, the particles combined to form neutral hydrogen. The bottom line is that in this case, our telescopes would not be able to detect the early light of the universe, because it would have to go through many different distortions.
After galaxies and other sources of energy appeared in the universe, they reionized the gas, scattered its dense accumulation and opened the way for light. However, this event took place already about a billion years later, so EGS8p7 is too far from us for us to see it. And yet, astronomers somehow note that they were able to catch the Lyman-alpha line of the galaxy, which is its kind of barcode. It manifests itself when a relatively young star begins to emit ultraviolet light into the surrounding gas, leaving behind a thermal signature. This signature was detected by the MOSFIRE spectrometer at the Keck Observatory in Hawaii.
And yet, the Lyman-alpha line of the galaxy EGS8p7 should have remained hidden by early opaque neutral hydrogen. Astronomers are not entirely sure how the light from EGS8p7 manages to break through such an obstacle. There is an assumption that the radiation of the local stars is so powerful that it reionized part of the universe much earlier than other galaxies.
Bonus: Ring of Andromeda
Our closest neighbor, the Andromeda galaxy (M31), is surrounded by a giant ring (or halo). Andromeda itself is twice the size of the Milky Way and extends over 200,000 light years. Moreover, its halo occupies a space of about 2 million light years. It acts as a beacon for astronomers looking for quasars here. Ultraviolet light, which reached the scientific instruments of the Hubble Space Telescope, gave scientists the idea of how such a giant ring of gas could form around Andromeda.
Partly made of galactic gas, the ring is a kind of huge storehouse of matter for future and emerging stars. It is also rich in heavy elements produced by supernovae, located on the borders of Andromeda and ejected beyond its limits. Unfortunately, the ring itself is invisible to the human eye, but in the night sky it would be 100 times the diameter of the full moon.
Nikolay Khizhnyak