Intracluster Light: Illuminating The Universe’s Dark Side

The universe has a dark side, singing an enchanting and mind-boggling Sirens’ song to astronomers trying to solve their myriad mysteries. Astronomers call one of its particularly enticing mysteries the “dark matter”. This is because they are “in the dark” about its true nature. However, many scientists suggest that the dark matter is an exotic and abundant ghostly material that cannot be seen because it does not dance with light or any other form of electromagnetic radiation. Nevertheless, while the dark stuff is invisible, astronomers generally think it really haunts the universe because it exerts an observable gravitational influence on objects that can be seen – such as fiery stars and the brilliant galaxies in which they reside. In December 2018, a team of astronomers announced that their new study of Hubble space telescope (HST) images could be an important step in illuminating this elusive, exotic substance, shedding new light on its mysterious and mysterious nature. Using HSTs previous observations of half a dozen massive galaxy clusters in the Frontier Fields program, the astronomers showed intracluster light– the soft and diffused glow that glistens between individual galaxies within a cluster – reveals the path this ghostly, transparent material travels through space, illuminating its dispersion with greater accuracy than other X-ray-sensing methods.

Intracluster light is the result of disruptive interactions between galaxies within a cluster. In the chaos that follows, individual stars are torn by the gravitational bands that bind them to their host system. These coarsely removed stars then realign with the entire cluster’s gravity map. This is also where most of the cluster is transparent dark matter hides in invisible secret. X-ray shows where galaxies collide, but does not reveal the underlying structure of the cluster itself. This makes X-ray light a less exact tracer of the dark stuff.

“The reason for that intracluster light is such an excellent tracer of dark matter in a galaxy cluster, both are dark matter and these stars form the intracluster light are free-floating on the gravity potential of the cluster itself – so they follow exactly the same gravity. We have found a new way to see the location where the dark matter should be, because you are following exactly the same gravity potential. We can illuminate the position of with a very faint glow dark matter, “ stated Dr. Mireia Montes on December 20, 2018 Hubblesite press release. Dr. Montes, from the University of New South Wales in Sydney, Australia, is a co-author of the study.

The discovery and quantification of the diffuse glow of intracluster light, streaming within galaxy clusters, provides a new and valuable resource for astronomers to study the history and structure of galactic clusters in more detail than previously possible. Because the intracluster light Coming from unfortunate orphaned stars living in galaxy clusters torn by gravity from their parent galaxies, it is a product of the dynamic interactions within the cluster. For this reason, the intracluster light has the potential to reveal much important information about the cluster’s growth and evolutionary past, as well as the mass distribution of the individual cluster systems themselves and the whole cluster as a whole. The morphology, quantity and kinematics of the intracluster light each provides potentially valuable information about the evolution of the cluster, and processes affecting individual galaxies can be detected using individual flows from intracluster light.

The dark side

The mysterious dark matter is believed to consist of exotic non-atomic particles that do not interact with electromagnetic radiation. This exotic material only dances with the so-called “normal” atom (baryonic) matter by gravity. According to the Standard model of cosmology, about 4.9% of the universe consists of “normal” atomic matter, 26.8% dark matter, and a whopping 68.3% dark energy. Indeed, the dark energy, which makes up most of the universe, is an even greater mystery than the dark matter. The most accepted explanation for the dark energy states that it is a property of space itself, and it causes the universe speed up in its expansion to its own “heat death”. As the universe accelerates in its expansion, it gets colder and colder; bigger and bigger – doomed to become a huge icy expanse as the fire flashes out like a dying candle flame.

The very poorly named ‘normal’ atomic matter is actually very special. While atomic matter is clearly the basis of the cosmic nest of three, it explains it Over there of the elements mentioned in the known Periodic table. The atomic elements create the world that we know most and that we can experience with our senses developed by the earth. Although atomic matter is only a relatively small part of the cosmos, it is what brought life to it. The iron in your blood, the calcium in your bones, the water you drink, the sand you walk on are all composed of so-called “ordinary” atomic matter. Most of the atomic elements were formed in the red-hot, nuclear fusion ovens of the myriad stars of the universe. The Universe’s Big Bang birth, believed to have taken place nearly 14 billion years ago, produced only the lightest atomic elements – hydrogen, helium, and trace amounts of lithium. The stars produced the rest in their incredibly hot cores, starting with the hydrogen and helium produced in the Big Bang, then creating ever heavier and heavier atomic elements down to iron through the process of nuclear fusion. However, the heaviest atomic elements of all – such as uranium and gold – were produced when a massive star blew itself up in a supernova explosion. These fiery, brilliant stellar blasts cast freshly forged heavy atomic elements into the space between stars – all crafted in the blazing hot heart of the ancestor massive star, or in its explosive agony.

According to the Standard model for the formation of the large-scale structure of the universe, exotic particles of the non-atomic dark matter first performed a gravity ballet with each other, building an overcrowded area of ​​space called the dark matter halo. Gradually the invisible primal comes halos composed of the dark stuff that picked up clouds of pristine hydrogen gas. Hydrogen is both the most abundant and the lightest atomic element in the universe. As a result, galaxies and their population of glittering stars emerged from this original darkness.

Vast, swirling and shapeless clouds of opaque, pristine ancient gases that have gathered in the primal darkness. The clouds then fell into the mysterious hearts of the strange halos of the dark issue. As time progressed toward universal expansion, the very first generation of baby stars were born. Then, the newly lit fires of the first stars raged brilliantly in the first ancient galaxies that fulfilled the important function of being original star cradles.

Despite dark issue cannot be seen, it is widely believed to exist because of the very important discrepancies that scientists have observed between the mass of large-scale celestial bodies – obtained from their calculated gravitational interactions – – and the mass measured from the visible atomic matter they host.

The possible existence of dark matter was first proposed by the Dutch astronomer Jan Oort (1900-1932) as a result of his dedicated effort to understand the orbital velocities of the constituent stars of our own Milky Way. In 1933, Swiss-American astronomer Fritz Zwicky (1898-1974) also proposed the existence of an exotic form of abundant and transparent matter. Zwicky came to this conclusion because I realized that some form of invisible “missing mass” spooked through the cosmos – and that this transparent and invisible exotic material affected the orbital velocities of constituent galaxies in distant galaxies. In 1939, strong evidence that the bizarre invisible matter really exists in nature was calculated from the rotation curves of galaxies by astrophysicist Horace W. Babcock (1912-2016) of the California Institute of Technology (Caltech) in Pasadena. However, Babcock did not realize that his highly suggestive observations indicate the presence of dark matter.

Finally, half a century ago, astronomer Vera Rubin (1928-2016) was the first scientist to provide convincing evidence for the existence of the dark stuff. In the 1960s, Rubin – who had studied Zwicky’s work as a graduate student – proposed her new theory that she was based on galactic rotation curves. Shortly after the publication of Rubin’s study, other astronomers made several important observations that also pointed to the existence of this exotic, ghostly form of transparent matter. The later studies were based on observations used gravity lensing background objects by foreground galaxy clusters, the distribution and temperature of hot gas within individual galaxies and galaxy clusters, and (more recently) the observed pattern of anisotropies that Cosmic microwave background (CMB) radiation that formed in the newborn universe at the time of its birth in the big bang. Gravity lensing is a phenomenon that Albert Einstein proposes in his General theory of relativity (1915), when I realized that gravity could distort the Spacetime – and for this reason would have lens-like effects.

The galaxies performing their fantastic dance throughout the visible universe were created less than a billion years after the Big Bang. In the very old Cosmos it is transparent, exotic dark matter entangled floating gas clouds that became the primal farms of the first generation of fiery stars to illuminate a once dark and colorless plain.

Finally the swirling floating gas clouds and the ghost dark matter met and carried out an old waltz throughout the universe. They gradually combined to create the familiar structures that now exist in the present cosmos.

The theoretical existence of dark matter is an integral part of recent scenarios describing the birth, evolution and formation of cosmic structures. Moreover, the real existence of this exotic form of matter is important because it explains the anisotropies found in the CMB– the residual radiation that remains after the tumultuous birth of the universe. All evidence so far indicates that galaxies, galaxy clusters, and the entire vast universe as a whole contain significantly more matter than can be observed by astronomers with electromagnetic radiation.

Expelled stars shed new light on the darkness

Co-author Dr. Montes noted that not only is the new method of use intracluster light accurate, it is also more efficient than other methods. This is because it only uses deep imaging, rather than the more complex, time-consuming techniques that use spectroscopy. For this reason, more clusters and other objects in space can be observed in less time, and it can provide more evidence of what dark matter is made of and how it behaves.

“This method allows us to statistically characterize the ultimate character of dark matter,Dr. Montes noted on December 20, 2018 Hubblesite press release.

The idea for the study came up while I looked at the pristine Hubble Frontier Fields Pictures. The Hubble Frontier Fields shown intracluster light in unprecedented clarity. The images were inspirational, “said study co-author Dr. Ignacio Trujillo Hubblesite press release. Dr. Trujillo is from the Canary Islands Institute of Astronomy in Tenerife, Spain and, with Dr. Montes, you studied intracluster light for many years.

“Still, I didn’t expect the results to be as accurate. The implications for future space-based research are very exciting,” added Dr. Trujillo is ready.

The team of astronomers used the Changed Hausdorff distance (MHD), a metric used when matching shapes, to match the contours of the intracluster light and the contours of different mass maps of the clusters, which are part of the data obtained from the Hubble Frontier Fields project. The Hubble Frontier Fields project is tracked on the Mikulski Archive for space telescopes (MAST). The MHD is a measure of how far two subsets are from each other. The smaller the value of MHDthe more the two point sets look alike. This study showed that the distribution of intracluster light as seen in the Hubble Frontier Fields images were more consistent with the mass distribution of half a dozen galaxy clusters than X-ray emission, as derived Chandra X-ray Observatory’s CCD Imaging Spectrometer (ACIS).

In the future, Drs. Montes and Trujillo have several options to expand their studies. First, they want to increase the beam of observation in the original six clusters to find out if the degree of tracking is accurate. A second important test of their method is the observation and analysis of additional clusters of galaxies by more research teams to enlarge the dataset and confirm their findings.

The astronomers are also looking forward to applying the same techniques with the help of future powerful space telescopes such as the James Webb Space Telescope (JWST) and FIRST, which contain even more sensitive tools to dim intracluster light in the distant universe.

Dr. Trujillo also wants to test the scale down of observations from massive galaxy clusters to individual, isolated galaxies. “It would be great to do this on a galactic scale, for example exploring the stellar halos. In principle, the same idea should work: the stars that surround the galaxy as a result of the fusion activity should also follow the galaxy’s gravitational potential, reducing the location and distribution of dark matter, ” I responded on December 20, 2018 Hubblesite press release.

The Hubble Frontier Fields program was an in-depth image initiative created to use the natural gravity magnifying glass of a cluster (gravitational lensing) to observe the extremely distant galaxies behind it and in this way gain new insight into the old (distant) universe and the evolution of galaxies since that very old time. In astronomy, long ago is the same as far away. The farther an object is in space, the older it is in time (Space time).

In the Hubble Frontier Fields program the magnifying glass of a foreground cluster that appears as the lenswhile the more distant galaxy behind the cluster was the magnified object lensed. For the astronomers of the Hubble Frontier Fields program, the diffuse intracluster light was annoying. This is because it partially eclipsed the distant galaxies behind it. However, that faint and distant glow of old starlight could shed new light on one of the most intriguing mysteries of astronomy – the nature of the exotic dark matter.



Source by Judith E Braffman-Miller