This image is the first all-sky image taken by eRosita. Each bright spot in the image is either a black hole or a neutron Star. (Image credit: Jeremy Sanders/Hermann Brunner/Andrea Merloni/Eugene Churazov/Marat Gilfanov/IKI/eSASS/MPE)German-built telescope has created the most detailed map of neutron stars and black holes in our universe. It revealed more than 3,000,000 new objects in just two years.The observatory, eROSITA was launched in 2019. It is the first space-based Xray telescope capable to imaging the entire sky. It is the main instrument aboard the Russian-German Spectrum-Roentgen-Gamma mission, which sits in a region known as Lagrange point 2, one of five stable points around the sun-Earth system, where the gravitational forces of the two bodies are in balance. eROSITA can see the entire universe from this vantage point. It photographs it using its powerful Xray detecting instruments.The team behind eROSITA was led by scientists at the Max Planck Institute for Extraterrestrial Physics, Germany. They released last month the first set of data from the instrument to the scientific community for exploration.Video: The Milky Way's core is filled with vibrant threads in a new X-ray panoramaFirst time X-rays of the entire skyThe telescope has already made interesting discoveries, such as the discovery of huge X-ray bubbles coming from the center the Milky Way. eROSITA's first science release is expected to shed light on long-standing cosmological mysteries, including the distribution and origin of dark energy in the universe. Andrea Merloni, a senior scientist at the mission, told Space.com.Merloni stated that this is the first time that an X-ray telescope can be used in a similar way to the large-field optical telescopes we currently use. "With eROSITA we can cover the entire sky very efficiently, and can study large-scale structures such as the entire Milky Way."Gaia, the European Space Agency's Gaia Mission, and the Very Large Telescope, which is based on the European Southern Observatory ground-based, all-sky surveys allow astronomers to image large areas of sky in one sweep. This allows them to study the motions of whole populations of stars and other celestial objects. Gaia, for instance, measures the positions of the stars in the Milky Way as well as their distances from Earth, with an unprecedented level of accuracy.Merloni stated that large survey optical telescopes have become very common because they can be used to study cosmology (the evolution of the universe) and other things like dark energy. "But optical telescopes are easier to construct than X-ray telescopes."Some of the most fascinating objects in the Universe, however, don't emit visible light and are therefore mostly invisible to optical telescopes. This includes neutron stars and black holes. However, X-rays make it easier to observe distant galaxy clusters. These are the complex structures found in the Universe and consist of conglomerations galaxies.However, previous X-ray telescopes such as NASA's Chandra X-ray Observatory or ESA's XMM Newton could only see a small portion of the sky at a time.Merloni stated that X-ray telescopes have so far been able to see very deeply into the centre of the universe to observe its early stages. It has been difficult to compile large numbers of black holes, neutron star clusters and other objects and then create a large catalog that could be used to study their cosmological evolution.The eROSITA telescope uses a lot the technology that was originally developed for ESA's veteran XMM Newton. It has been orbiting Earth ever since 1999. Merloni explained that the telescope produces images with the same quality and a wider field of view as XMM Newton thanks to technical adjustments by the Max Planck Institute team, their collaborators.eRosita detects bright X-ray glows emitted from hot gas in galaxy clusters. These are some of the most complex structures in all of the universe. (Image credit: Esra Bulbul, Jeremy Sanders (MPE))The map of black holes within the universeeROSITA began taking its first images in October 2019. Merloni stated that eROSITA has since completed three all-sky surveys. These maps show the distribution of Xray radiation sources in the sky.Although this data is not yet available to the general scientific public, Merloni stated that the catalogues include information about approximately 3 million sources of Xray radiation black holes and neutron stars. Nearly 77% of these sources are distant black hole in other galaxies, while 20% are stars, neutron stars, and black holes within the Milky Way. He added that the remaining 3% of those sources are galaxy clusters.Merloni stated that there were approximately a million [X-ray] sources in the 50 years of Xray astronomy from eROSITA. Although some of the evidence is still being validated, we have already found three times more than was previously known.Merloni said that most of the objects previously discovered were located in pockets. This is because Chandra and XMM–Newton excel at diving into the smallest parts of the universe. On the other hand, the new black holes, clusters, and neutron stars discovered by eROSITA were evenly distributed across the sky.Just like Gaia allowed scientists to go beyond studying individual stars and visualize the motions, dynamics, and evolution of the galaxy, so eROSITA will also open up new opportunities.How clusters transform from 'villages to cities'Merloni is particularly excited about the potential eROSITA findings about the evolution and formation of clusters, large groups of hundreds to thousands galaxies linked by gravity. Clusters are a result of galaxy collisions. They first appeared around 10 billion years ago, and have grown steadily over billions of years, from small "villages", to large "megacities".astronomers will be able to reconstruct the evolution and development of massive structures through the ages with eROSITA's ability to see distant objects that require 7 billion years for their light to reach it.Merloni stated that clusters can be seen even without X-ray telescopes, but it may be difficult to separate them from other galaxy populations. "What we see in the X-rays are the gases between galaxies within a cluster that get very hot and emits an X-ray glow. These clusters are easily distinguished in eROSITA images because of their shine.Astronomers can create a timeline for cluster evolution by studying clusters at different distances (and thus of different ages) and shed light on what drives it.Merloni stated that by discovering large numbers of clusters, it is possible to understand whether the gradual conglomeration galaxies occurred faster or slower. This will allow us to understand the density of dark matter, dark energy and how quickly these clusters form.Dark matter is thought to be responsible most of the gravitational force within the universe. However, dark energy, the mysterious repulsive force that counteracts gravity has not yet been observed or measured.To get the most precise information about the location of clusters, the eROSITA measurements will need to be combined with data from Gaia and other observatories such as Gaia, Vera Rubin, and others.Merloni said, "With precise data on these clusters we will be in a position to place some constraints on dark energy equations and make our contribution to the big enterprise of cosmic analysis."In June 2021, the European Astronomical Society presented the first public eROSITA data data release. It contained data gathered in the first two months of eROSITA operations. This is only the beginning of this effort. Although the mission's main science task will be completed in 2023 by the mission, astronomers expect it to remain operational for many years. Merloni stated that scientists will be busy for many decades with the catalogs of Xray emitting objects throughout the universe.Merloni stated that Rosat was the previous X-ray all-sky survey mission. "It only did one all-sky survey in 1990. It was probably 10 times deeper and more accurate than ours. People published papers on this basis for more than 30 years."Follow Tereza Pultarova @TerezaPultarova. Follow us on Facebook and Twitter @Spacedotcom
