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The top step of the Proton rocket and DM block block was mounted Saturday in space from the Baikonur Cosmodrome in Kazakhstan with Spektr-RG, an astronomical observatory equipped with two X-ray telescopes developed by Russian and German scientists looking for the signature of black energy.
The new observatory will detect X-ray emissions from the sky, including those from huge clusters of galaxies. By measuring the mass, luminosity and distance of distant galaxies, Spektr-RG could help astronomers better understand the dark energy, the mysterious force behind the accelerated expansion of the universe.
During a four-year survey covering all heavens, the mission will sweep the entire sky eight times. By the end of its comprehensive survey, Spektr-RG could discover millions of new sources of X-rays, creating a statistical catalog of objects and cosmological structures to fill the gaps in the map of the known universe , according to Mikhail Pavlinsky. the main scientist of the IKI mission, the Institute of Space Research of the Russian Academy of Sciences.
The Spektrum-Röntgen-Gamma mission, also known as Spektr-RG, sits in a 57 meter high Proton rocket in clear skies above Baikonur, a historical space base in the Kazakhstan steppe. The takeoff took place at 12:30: 57 GMT (8:30 am: 57 am EDT) to begin a two hour launch sequence, which resulted in the deployment of the Spektr-RG spacecraft after two shots fired by the engine from the floor Superior Proton's Block DM.
Roscosmos, the Russian space agency, announced the successful separation of the Spektr-RG spacecraft from 5,980 pounds (2,712.5 kilograms), and confirmed that the spacecraft was extending its solar panels generating power while it began a three-month cruise to an observation post 1.5 million kilometers from the night side of the Earth.
Scientists have chosen Spektr-RG's distant pole to give the observatory an unobstructed view of the entire sky, without the Earth or the sun drifting regularly in the probe's field of vision. Spektr-RG is moving to a location known as the L2 Lagrange Point, a gravitational stable site housing several other space telescopes.
The Russian and German teams participating in the Spektr-RG mission announced the successful launch, which took place on Saturday after June 21, to allow the launch teams in Baikonour to replace the launcher battery. The Russian authorities then canceled a launch attempt on Friday to address a separate technical issue with the Proton launcher.
"The launch was not easy, but everything worked perfectly," tweeted Dmitry Rogozin, director of Roscosmos. "The rocket, the propeller and the spaceship did not let us down."
Spektr-RG is a mission led by Russia, but its main instrument comes from Germany.
Astronomers from the Max Planck Institute for Extraterrestrial Physics, or MPE, in Germany, are leading the eROSITA telescope, an instrument consisting of seven individual mirror modules. Scientists have designed eROSITA – the extensive ROentgen survey with a network of imaging telescopes – following the German ROSAT mission, launched in 1990 and which led the first ray imaging study X on open sky.
A second X-ray telescope on Spektr-RG, developed by a Russian scientific team, will be sensitive to higher energy X-rays than eROSITA. The Russian telescope, named ART-XC, will fly with X-ray mirror modules made at NASA's Marshall Space Flight Center in Alabama.
The Earth's atmosphere absorbs X-rays. Astronomers must therefore use satellites or balloons at high altitude for X-ray observations, which is useful for observing black holes and large cosmic structures with clouds. overheated gas.
"It's the time of this bottle!" Tweeted Kirpal Nandra, director of the High Energy Astrophysics group at MPE, where astronomers celebrated the launch with champagne.
MPE celebrates success @eROSITA_SRG launching #eROSITA pic.twitter.com/SvXL4LrONr
– Johannes Buchner (@JohannesBuchner) July 13, 2019
Ground crews received the first Spektr-RG telemetry shortly after deployment from the Proton / Block DM launcher.
"We designed eROSITA to transform our vision of the sky into X-rays and solve the mysteries of cosmology and black holes," said Peter Predehl, senior research scientist at the eROSITA telescope at MPE. "This is the moment when the efforts of the team that has been working for more than a decade are coming to fruition."
In the coming weeks, engineers will order the spacecraft, built by the Russian contractor NPO Lavochkin, to open protective covers protecting the optics of the eROSITA and ART-XC instruments, thus allowing ground crews to start calibrating the telescopes.
The journey from Spektr-RG to L2 Lagrange point will take more than three months. The X-ray survey on all the heavens of the mission should begin in early November.
The observatory's mission is expected to last seven years, four of which will be dedicated to the study of the integral sky, followed by three years of targeted observations to monitor specific targets.
Up to 80% of what Spektr-RG sees has been previously undetected, Pavlinsky said. An automatic analysis of the data collected by the observatory will determine what is new and what has been cataloged.
"We will discover 80% of new sources every day," Pavlinsky said in an interview with Spaceflight Now. "It's a few hundred sources a day, which means that in four years we will receive a lot of new information.
The only observations from the eROSITA telescope will help astronomers find 100,000 clusters of X-ray galaxies never discovered, several million active black holes in the center of galaxies and rare objects such as isolated neutron stars, the collapsed remains left by stellar cataclysmic explosions. , according to MPE.
"In its first year, eROSITA will discover more new sources of X-rays than those seen in more than 50 years of X-ray astronomy history," scientists wrote in a press release.
"These will be sources we will not find in any catalog," Pavlinsky said. "It's a big challenge for us. We do not know exactly what it will look like. "
"That goes in the direction of (the study) of dark energy," Predehl said in an interview prior to the launch of Spaceflight Now.
Black energy is the term assigned by cosmologists to the hidden force that causes the accelerated expansion of the universe. Scientists believe that dark energy accounts for about 70% of the universe's energy density, according to NASA, a dark matter that exerts gravitational attraction but emits no light. It constitutes about 25% of the universe.
Scientists say that ordinary matter – things we can see – only accounts for about 5% of the universe.
Gravitational links bring galaxies together in groups and clusters along gigantic filaments of hot gas. The filamentary canvas is composed of ordinary matter and dark matter.
"You may have seen a simulation of the filamentary structure of the universe and, at the crossing points of these filaments, clusters form," Predehl said. "The growth of a cluster is dominated by dark matter, and the expansion of the universe, which can be measured by the specific density variable over time, depends on black energy . "
"What bunches do … is that they grow because they collect more and more mass from the outside, from all the filaments," Predehl said. .
Scientists do not know what constitutes black energy, whether it has been constant in the history of the universe or whether its influence will fade over time.
"The two dark components contribute to the model of cosmology," Predehl said.
Spatial missions set to measure microwave signals from the ancient universe mapped the distribution of matter over the first 380,000 years following the Big Bang, 13.8 billion years ago. .
Spektr-RG could "constrain" the parameters of the cosmological model that tries to explain the engine of the expansion of the universe, according to Predehl.
"We know what the universe looked like 13 billion years ago and what it looks like today, but between the two, there are many (unknown), and we hope fill some with eROSITA, "said Predehl.
The observation of so many galactic groups will allow astrophysicists to constitute a sample large enough to assess their distribution in the universe.
"We need statistics about clusters because clusters are the largest entities gravitarily related to the universe. Their counting and measurement of clump mass give you the specific density of the universe in relation to time, "said Predehl. "So, the evolution of the universe can be studied by measuring that."
"The main scientific goal of eROSITA is to reveal the large-scale structure of the universe and the way this structure is developing over cosmic time," said Andrea Merloni, project scientist eROSITA. "This could help reveal the properties of the mysterious" dark energy "that separates the universe.
"The clusters of galaxies that dot this structure are filled with gas at temperatures equal to or greater than a million degrees," Merloni said. "To see this directly, you have to use an X-ray telescope. With eROSITA covering the whole sky, we can see enough to accurately reconstruct their growth history. This, in turn, tells us something about the quantity, and perhaps the nature, of black energy and dark matter. "
According to German scientists, the eROSITA instrument is 20 to 25 times more sensitive than its predecessor, ROSAT. Spektr-RG X-ray detectors are also sensitive to higher energy X-rays than ROSAT.
Astronomers say that eROSITA is complementary to other X-ray telescopes, such as NASA's Chandra Observatory, which are more sensitive but designed for sharp imaging of individual X-ray sources. The ROSITA data could serve as a roadmap for Chandra and future X-ray missions to pursue targeted observations.
"We have a virtually unlimited field of view, so we can detect large diffuse structures in the sky," Predehl said.
The telescope should be able to see some galaxies aged about 13 billion years, Pavlinsky said. Other phenomena observable with Spektr-RG include pulsars and gamma-ray bursts, the most violent explosions in the universe.
"We will see some of the first supermassive black holes in our universe," he said.
"Earlier this year, we saw the first image of a supermassive black hole sitting in the center of a galaxy," Nandra said in a statement. "EROSITA will now tell us when and where this monster and a million others like him have grown over cosmic time.
"It's amazing how much our understanding of the universe has grown, and that's largely thanks to new instruments using advanced technologies," said Nandra. "EROSITA is the pinnacle for our group and I am incredibly proud of the team that made it a reality."
Researchers will compare mission X-ray detections with optical, infrared and radio telescope data to look for counterparts to Spektr-RG discoveries in other light bands.
Rooted in the Soviet space program, Spektr-RG was set apart in the 1990s during an economic downturn in Russia, and then was relaunched in 2005 on a smaller scale through crucial contributions international partners.
"We had an ambitious plan for the project that did not match the power of the country right now," Pavlinsky told Spaceflight Now. "We decided to restart it with a smaller version."
The Russian and German space agencies signed an agreement in 2009 to jointly develop the Spektr-RG mission, but additional scheduling delays were attributed to the project due to technical problems and the decision to pass the observatory. 39, a Zenit launcher to a Proton rocket.
The designers also changed the Spektr-RG observation position from an orbit around the Earth to a looped path around the L2 Lagrange point.
Spektr-RG is the largest Russian astronomy satellite to have been launched since the Spektr-R radio observatory in 2011. Spektr-R stopped responding to ground commands in January after exceeding the duration of expected life of his five-year mission. Russian officials said in April.
According to Predehl and Pavlinsky, the total cost of the Spektr-RG project is roughly equivalent to a medium-sized scientific mission of the European Space Agency. The cost of Spektr-RG is therefore approximately $ 600 million.
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Follow Stephen Clark on Twitter: @ StephenClark1.
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