The most distant galaxy. Distant galaxies

The science

The recently discovered celestial object is vying for the title of the most distant observable space object in the Universe, astronomers said. This object is a galaxy MACS0647-JD, which is located 13.3 billion light years from Earth.

The universe itself, according to scientists, has an age of 13.7 billion years, so the light of this galaxy, which we can see today, is its light from the very beginning of the formation of space.

Scientists observe object using NASA space telescopes Hubble and "Spitzer" and these observations were made possible by the natural cosmic "magnifying lens". This lens is actually a huge cluster of galaxies, whose overall gravity warps spacetime, producing what is called gravitational lens... When light from a distant galaxy passes through a lens like this on its way to Earth, it is amplified.

This is what a gravitational lens looks like roughly:

"Such lenses are able to magnify the light of an object so much that no man-made telescope can do it., - is talking Marc Postman, astronomer from Scientific Institute space telescope in Baltimore. - Without such an increase, a titanic effort must be made to see such a distant galaxy. "

A new, distant galaxy is very small, much smaller than our Milky Way.- said the scientists. This object, judging by the light that reached us, is very young, it came to us from an era when the Universe itself was at its very early stage its development. She was only 420 million years old, which is 3 percent of modern age.

The small galaxy is only 600 light years wide, and as you know, the Milky Way is much larger - 150 thousand light years wide. Astronomers believe that MACS0647-JD eventually merged with other smaller galaxies to form a larger one.

Cosmic merger of galaxies

"This object is possibly one of the many building blocks of some larger galaxy,- say the researchers. - Over the next 13 billion years, it could go through tens, hundreds or even thousands of mergers with other galaxies or their fragments. "

Astronomers continue to observe even more distant objects, thanks to the fact that their techniques and instruments for observation are improved. The previous object, which bore the title of the most distant galaxy observed, was the galaxy SXDF-NB1006-2, which is located at a distance of 12.91 billion light years from Earth. This object was spotted with telescopes. "Subaru" and "Kek" in Hawaii.

At the edge of the galaxy

The most distant space objects located so far from Earth that even light years are a ridiculously small measure of their distance. For example, the closest cosmic body to us - the Moon is located only 1.28 light seconds from us. How can we imagine distances that a light pulse cannot cover in hundreds of thousands of years? There is an opinion that it is incorrect to measure such a colossal space with classical quantities, on the other hand we have no others.

The most distant star in our Galaxy is located in the direction of the constellation Libra and is removed from the Earth at a distance that can be covered by light in 400 thousand years. It is clear that this star is located at the borderline, in the so-called galactic halo zone. After all, the distance to this star is about 4 times the diameter of the imaginary expanses of our Galaxy. (Diameter Milky way estimated at about 100 thousand light years.)

Beyond the galaxy

It is surprising that the most distant, rather bright star discovered only in our time, although it was observed earlier. For incomprehensible reasons, astronomers did not pay special attention to a faintly luminous speck in the starry sky and distinguishable on a photographic plate. So what happens? People have seen a star for a quarter of a century and ... do not notice it. More recently, American astronomers from the Lowell Observatory discovered another of the most distant stars in the peripheral limits of our Galaxy.

This star, already tarnished from "old age", can be looked for in the sky in the constellation Virgo, at a distance of about 160 thousand light years. Such discoveries in the dark (literally and figuratively) parts of the Milky Way make it possible to make important adjustments in determining the true values ​​of the mass and size of our star system in the direction of their significant increase.

However, even the most distant stars in our galaxy are located relatively close. The most distant of known to science quasars are located more than 30 times further.

Quasar (English quasar - short for QUASi stellAR radio source - "quasi-stellar radio source") is a class of extragalactic objects characterized by very high luminosity and such a small angular size that for several years after their discovery, they could not be distinguished from "point sources" - stars.

Not so long ago, American astronomers discovered three quasars, which are among the "oldest" objects in the Universe known to science. Their distance from our planet is more than 13 billion light years. Distances to distant space formations are determined using the so-called "redshift" - a shift in the radiation spectrum of rapidly moving objects. The further they are from the Earth, the faster, in accordance with modern cosmological theories, they move away from our planet. The previous range record was recorded in 2001. The redshift of the then discovered quasar was estimated at 6.28. The current trinity has offsets of 6.4, 6.2, and 6.1.

Dark past

Open quasars are only 5 percent younger than the universe. What came before them, immediately after the Big Bang, is difficult to fix: hydrogen formed 300,000 years after the explosion blocks the radiation of the earliest space objects... Only an increase in the number of stars and the subsequent ionization of hydrogen clouds makes it possible to break the veil over our "dark past".

To obtain and verify such information, you need joint work several powerful telescopes. The Hubble Space Telescope and the Sloan Digital Telescope, located at the New Mexico Observatory, play a key role in this endeavor.

Galaxies are gravitationally bound systems of stars, interstellar gas, dust, and dark matter. The diameter of galaxies ranges from 5 to 250 kiloparsecs. It's a lot.

For example, the diameter of our Galaxy is 30 kiloparsecs - light from one edge to another will fly for 100 thousand years. And there are at least 200 billion stars in it ...

1. Barred spiral galaxy NGC 4639 in the constellation Virgo. It is located more than 70 million light years from Earth. (Photo by Reuters | NASA | ESA | Hubble):

2. The Veil Nebula is a huge and relatively faint supernova remnant. The star exploded about 5000-8000 years ago, and during this time the nebula covered an area of ​​3 degrees in the sky. The distance to it is estimated at 1,400 light years. (Photo by Reuters | NASA | ESA | Hubble):

3. More than a fifth of the Universe is hidden from our view by dust and stars from the disk of our galaxy. Many galaxies are in the "zone of avoidance," a region of space that telescopes generally cannot reach. This is how they might look according to the imagination of the artists. (Photo by Reuters | ICRAR):

4. Centaurus A is one of the brightest and closest neighboring galaxies, we are only 12 million light years apart. In terms of brightness, the galaxy ranks fifth (after the Magellanic Clouds, the Andromeda nebula and the Triangle galaxy). (Photo by Reuters | NASA):

5. Barred Spiral Galaxy M83, also known as South Pinwheel. It is located at a distance of approximately 15 million light years from us. In 2014, astronomers discovered MQ1, which is light in itself, but absorbs the surrounding matter with great intensity. (Photo by Reuters | NASA):

6. Galaxy M 106 in the constellation Hounds Dogs. The core contains a supermassive black hole with a mass of 36 million solar masses within 40,000 astronomical units. (Photo by Reuters | NASA):

7. Part of the Tarantula nebula located in the Large Magellanic Cloud. The huge stars of the nebula are powerful sources of radiation that blows giant bubbles out of interstellar gas and dust. Some of the stars exploded into supernovae, causing the bubbles to be illuminated by X-rays. (Photo by Reuters | NASA):

8. Spiral galaxy NGC 1433 with a bar in the constellation Clock, located at a distance of about 32 million light-years from Earth. (Photo by Reuters | NASA | ESA | Hubble):

9. Galaxy NGC 1566, located at a distance of about 40 million light-years from Earth in the constellation Dorado. (Photo by Reuters | NASA | ESA | Hubble):

10. X-rays young supernova in the galaxy M83. (Photo by Reuters | NASA):

11. Spiral galaxy M94 in the constellation Canine Hounds. The galaxy is notable for the fact that it has two powerful ring-shaped structures. (Photo by Reuters | NASA | ESA):

12. Spiral galaxy NGC 4945 barred in the constellation Centaurus. It is quite similar to our Galaxy, but X-ray observations show the presence of a Seyfert core, probably containing an active supermassive black hole... (Photo by Reuters | NASA):

13.z8 GND 5296 is a galaxy discovered in October 2013 in the constellation Ursa Major. According to preliminary estimates, light from this galaxy reaches Earth in approximately 13 billion years. This is not a snapshot, but an artistic image. (Photo by Reuters | NASA | Hubble):

14. The Witch's Head Reflection Nebula (IC 2118) in the constellation Eridanus. This highly distinctive reflection nebula is associated with the bright star Rigel in the constellation Orion. The nebula is located about 1000 light-years from the Sun. (Photo by Reuters | NASA):

15. Galaxy Sunflower in the constellation Hounds Dogs. It is located at a distance of 27 million light years. (Photo by Reuters | NASA | ESA | Hubble):

16. The core of the spiral galaxy M 61 in the constellation Virgo. And only about 100,000 light years away. (Photo by Reuters | NASA | ESA | Hubble):

17. Spiral galaxy Fireworks NGC 6946 with a bar, which is located at a distance of 22 million light years in the constellation Cygnus, on the border with Cepheus. (Photo by Reuters | NASA):

18. A cloud of hot gas, with a temperature of many millions of degrees. It appeared, most likely as a result of a collision of a dwarf galaxy and much larger galaxy NGC 1232, located in the constellation Eridanus. (Photo by Reuters | NASA):

19. Galaxy NGC 524 in the constellation Pisces. From us the light will fly there for 90 million years. (Photo by Reuters | NASA | ESA | Hubble):

20. The Crab Nebula is a gaseous nebula in the constellation Taurus, which is a supernova remnant. Located about 6,500 light years (2 kpc) from Earth, the nebula is 11 light years (3.4 pc) in diameter and is expanding at a speed of about 1,500 kilometers per second. At the center of the nebula is a pulsar (neutron star), 28-30 km in diameter. (Photo by Reuters | NASA | ESA):

In May 2015, the Hubble telescope recorded an outburst of the most distant, and therefore the oldest known to date, galaxy. It took the radiation as much as 13.1 billion light years to reach Earth and be detected by our equipment. According to scientists, the galaxy was born about 690 million years after the Big Bang.

One would think that if the light from the galaxy EGS-zs8-1 (namely such an elegant name given to it by scientists) flew to us for 13.1 billion years, then the distance to it would be equal to the distance that the light will travel in these , 1 billion years.

Galaxy EGS-zs8-1 - the most distant among all discovered to date

But we must not forget some of the features of the structure of our world, which will greatly affect the calculation of distance. The fact is that the universe is expanding, and it does so with acceleration. It turns out that while the light went 13.1 billion years to our planet, space expanded more and more, and the galaxy was moving away from us faster and faster. An illustrative process is shown in the figure below.

Given the expansion of space, the most distant galaxy EGS-zs8-1 is currently located about 30.1 billion light years from us, which is a record among all other similar objects. It is interesting that until a certain moment we will discover more and more distant galaxies, the light of which has not yet reached our planet. It is safe to say that the galaxy record EGS-zs8-1 will be broken in the future.

It is interesting: there is often a misconception about the size of the universe. Its width is compared to its age, which is 13.79 billion years. This does not take into account that the universe is expanding with acceleration. According to rough estimates, the diameter of the visible universe is 93 billion light years. But there is also an invisible part of the universe, which we will never be able to see. Read more about the size of the universe and invisible galaxies in the article ““.

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The universe is a damn big place. When we look at the night sky, almost everything that can be seen with the naked eye is part of our galaxy: a star, a cluster of stars, a nebula. Behind the stars of the Milky Way, for example, is the Triangulum galaxy. We find these "island worlds" everywhere in the universe, wherever we look, even in the darkest and empty spots of space, if only we can collect enough light to look deep enough.

Most of these galaxies are so distant that even a photon traveling at the speed of light will take millions or billions of years to traverse intergalactic space. Once it was emitted from the surface of a distant star, and now it has finally reached us. And while the speed of 299,792,458 meters per second seems incredible, the fact that we have traveled only 13.8 billion years since the Big Bang means that the distance that light has traveled is still finite.

You probably think that the farthest galaxy from us should be no further than 13.8 billion light years from us, but that would be a mistake. You see, in addition to the fact that light travels at a finite speed through the universe, there is another, less obvious fact: the fabric of the universe itself expands over time.

Solutions general theory relativity, which ruled out such a possibility altogether, appeared in 1920, but observations that came later - and showed that the distance between galaxies is increasing - allowed us not only to confirm the expansion of the universe, but even to measure the rate of expansion and how it changed over time ... The galaxies we see today were much further from us when they first emitted the light we received today.

Galaxy EGS8p7 currently holds the record for distance. With a measured redshift of 8.63, our reconstruction of the universe tells us that it took the light of this galaxy 13.24 billion years to reach us. With a little more math, we find ourselves seeing this object when the universe was only 573 million years old, just 4% of its current age.

But because the universe has been expanding all this time, this galaxy is not 13.24 billion light years away; in fact, it is already 30.35 billion light years away. And don't forget: if we could instantly send a signal from this galaxy to us, it would cover a distance of 30.35 billion light years. But if you instead send a photon from this galaxy towards us, then thanks to dark energy and the expansion of the fabric of space, it will never reach us. This galaxy is already gone. The only reason we can observe it with the Keck and Hubble telescopes is that the neutral gas blocking light in the direction of this galaxy was quite rare.

Hubble Mirror vs. James Webb Mirror

But don't think that this galaxy is the most distant of the most distant galaxies we will ever see. We see galaxies at such a distance, as far as our equipment and the Universe allow us: the less neutral gas, the larger and brighter the galaxy, the more sensitive our instrument, the further we see. In a few years, the James Webb Space Telescope will be able to look even further, as it will be able to capture light of a longer wavelength (and therefore with a higher redshift), will be able to see light that is not blocked by neutral gas, will be able to see fainter galaxies than our modern telescopes (Hubble, Spitzer, Keck).

In theory, the very first galaxies should appear with a redshift of 15-20.