German-Russian Astronomy Satellite tv for pc Launches – Sky & Telescope

July 14, 2019 - Comment

Spektrum-Röntgen-Gamma, a long-delayed and much-modified X-ray astronomy bundle, launched efficiently from the Kazakh Steppe on Saturday. The Spektrum-Röntgen-Gamma (Spektr-RG) satellite tv for pc took to the skies on Saturday, July 13th, at 17:31 native time (12:31 UT). The Proton rocket carrying the spacecraft launched from the Baikonur Cosmodrome on the Kazakh Steppe in Russia. The


Spektrum-Röntgen-Gamma, a long-delayed and much-modified X-ray astronomy bundle, launched efficiently from the Kazakh Steppe on Saturday.

The Spektrum-Röntgen-Gamma (Spektr-RG) satellite tv for pc took to the skies on Saturday, July 13th, at 17:31 native time (12:31 UT). The Proton rocket carrying the spacecraft launched from the Baikonur Cosmodrome on the Kazakh Steppe in Russia.

The launch will set Spektr-RG on its means for the following three months, till it reaches a secure photo voltaic orbit 1.5 million kilometers (1 million miles) from Earth, on the alternative facet from the Solar. From there, two telescopes — one German and one Russian — will perform investigations of the X-ray universe.

Spektrum Roentgen Gamma in cleanroom

Spektrum-Röntgen-Gamma within the clear room, prepared for launch.
Roscosmos / DLR / SRG / Lavochkin

The Telescopes

X-rays penetrate most supplies — together with mirrors — so focusing them requires a novel design. Each the German area company’s Prolonged Roentgen Survey with an Imaging Telescope Array (EROSITA) and the Russian Astronomical Roentgen Telescope – X-ray Concentrator (ART-XC) include a number of modules of concentric mirror pairs. X-rays skip off two mirrors at grazing incidence angles, like clean pebbles off a pond, coming to a concentrate on the X-ray detectors.

Every of EROSITA’s seven “eyes” accommodates 54 mirror pairs, nested inside one another like Russian dolls. These mirrors focus X-rays onto CCD detectors with 15-arcsecond decision. Such pictures received’t have the sub-arcsecond high quality of, say, a Hubble or Chandra picture, however however the pictures will cowl all the X-ray sky. Certainly, EROSITA will survey the total sky not simply as soon as, however eight instances over 4 years. In contrast with the final all-sky survey, performed with the ROSAT mission within the 1990s, EROSITA could have 20 to 25 instances the sensitivity. It can uncover sources by no means seen earlier than — by the tens of millions.

“EROSITA will map all the sky in X-rays as much as 10 keV for the primary time,” says workforce member Esra Bulbul (Heart for Astrophysics, Harvard & Smithsonian). “The science span of eROSITA is remarkably large. It can detect massive variety of X-ray transients, supernova remnants, galaxies, clusters of galaxies, filaments connecting clusters, and the warm-hot intergalactic medium.”

EROSITA's seven mirror modules

EROSITA’s seven mirror modules are on show.
P. Friedrich / MPE

Like EROSITA, the Russian ART-XC accommodates seven mirror modules, although with fewer mirror shells inside each: 28 as an alternative of 54. Complementing the lower-energy photons that EROSITA is delicate to (300 to 10,000 electron volts), ART-XC will focus greater X-ray energies, from 5,000 to 30,000 electron volts. The 2 overlap within the center, which is able to support the calibration of each devices. The trade-off for ART-XC’s sensitivity to greater energies will probably be its fuzzier pictures, with a decision of 45 arcseconds. It can even have a narrower discipline of view.

In an instance of Russian-American collaboration, NASA’s Marshall Area Heart developed and calibrated ART-XC’s mirror programs. These had been then put in on the Russian Federal Nuclear Heart in Sarov, Russia, the place the telescope was constructed.

Probing Darkish Vitality with X-ray Imaginative and prescient

The first science aim for EROSITA, and one of many targets of ART-XC, is to higher characterize darkish power, the unknown drive that’s figuring out the universe’s enlargement price and supreme destiny. EROSITA’s survey is anticipated to choose up 100,000 galaxy clusters, with which astronomers will examine the character of this mysterious drive.

Clusters of galaxies characterize the most important gravitationally sure buildings within the universe. Stars make up only one% or so of the cluster’s matter, and EROSITA received’t see the celebrities anyway. As an alternative, the telescope will detect clusters by the X-rays coming from the tenuous however plentiful gasoline swirling between galaxies. The place a visible-light telescope sees a galaxy cluster as a set of factors of sunshine, EROSITA will see an X-ray blob. However, importantly, EROSITA will see these blobs out to unimaginable distances.

Simulation of EROSITA all-sky survey

This simulated picture exhibits what EROSITA will see in its all-sky survey.
T. Dauser / Remeis-Observatory / FAU / EROSITA Group

Within the 1990s, ROSAT measured X-rays from close by galaxy clusters, figuring out that “regular” matter (that’s, the baryonic matter that makes up stars, planets, and also you and me) makes up about 30% of the universe’s complete matter. Starting in mid-October, EROSITA will begin making the observations to increase that measurement to when the universe was half its present age. By cataloging galaxy clusters that far again, astronomers can measure adjustments in large-scale construction over cosmic time.

The Mission That May

Right now marks the triumphant conclusion of Spektr-RG’s lengthy journey to the launchpad. Born within the 1990s, the mission was put aside throughout a Russian financial downturn earlier than being resuscitated in 2005. The revived mission was smaller and integrated extra worldwide cooperation, however nonetheless suffered a collection of delays from an unique launch date of 2011.

On its decade-long journey to the launchpad, EROSITA had its share of speedbumps, too. “I haven’t counted the sleepless nights over the past 10 to 12 years,” says Principal Investigator Peter Predehl (Max Planck Institute for Extraterrestrial Physics, Germany). “Every time I believed I used to be out of the woods, the following one would come.”

EROSITA’s mirrors, that are scaled-down variations of these flown aboard the XMM-Newton satellite tv for pc, turned out to be harder to scale than initially thought. Then the satellite tv for pc electronics rapidly turned sophisticated. “Electrical engineers are a nightmare for any who has to handle such a venture,” Predehl says, tongue firmly in cheek. “They will’t be managed, they don’t comply with any order, they usually do what the need — however what they do is superb.”

Now that the mission is lastly launched, anticipation is excessive. “After the commissioning and calibration, we could have the primary mild — this at all times a particular and holy second for the principal investigator,” Predehl says.

However first mild solely marks the start: “We can’t anticipate to get breaking science information very quickly,” Predehl notes. “However will probably be thrilling to see the sky being slowly coated.” All of its observations, he provides, will probably be made out there in real-time. After 4 years of sweeping the X-ray sky, EROSITA will dedicate one other three years to focused observations. Watch the video beneath to be taught extra about EROSITA and its mission:



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