Behind every piece of information found about the observable universe, there are hundreds of engineers and technicians that work hard for years at an end using space crafts, telescopes of all kinds, and n number of instruments that help them get close and personal with unknown astronomical objects.
X-ray telescopes are different than other types of telescopes for example the Hubble Space Telescope. They are very energetic and have a small wavelength that can pass through most objects, even mirrors. Using the sharp X-ray images that could not be detected otherwise, scientists understand the physics behind supernova remnant expansions and distribution of gas in the universe among other things.
Here are the top 10 X-ray telescopes that have played a monumental part in pealing the unknown universal truths!
Suzaku
Developed jointly by NASA’s Goddard Space Flight Center and Institute of Space and Aeronautical Science at Japan Aerospace Exploration Agency (JAXA), Suzaku is an X-ray astronomy satellite that explored high energy sources including black holes, supernova explosions, and galactic clusters. The satellite was named after the mythical bird of the south – Vermilion. The M-V rocket carrying the Suzaku satellite was launched on the 10th of July 2005. The spacecraft carried 4 instruments – the X-ray Telescope, the X-ray Spectrometer, the X-ray Imaging Spectrometer, and the Hard X-ray Detector. The mission was considered a success as the telescope found fossil light coming from a supernova remnant.
ROSAT
ROSAT or Röntgensatellit is a German Aerospace Center X-ray telescope with instruments that are built by the United Kingdom, the United States, and West Germany. It was named in honor of German physicist and mechanical engineer Wilhelm Röntgen who, in 1901, was the winner of the first Nobel Prize in Physics. The ROSAT’s strength lies in its low-background, high spatial resolution, and soft X-ray imaging. The space telescope was launched on June 1, 1990, from Brevard County, Florida. The mission lasted for 8 years and 8 months till 12 February 1999. The telescope decayed on October 23, 2011, over the Bay of Bengal.
XMM-Newton
With several observations and discoveries under its belt, XMM-Newton (previously named High Throughput X-ray Spectroscopy Mission or X-ray multi-mirror mission) is an X-ray astronomy satellite that was launched in December 1999 by ESA (European Space Agency). The mission was initially designed for a 10-year lifespan. However, as the spacecraft is still in good health, the mission is ongoing until the end of 2020. It is speculated that the craft will get a 2-year extension till 2022. The space observatory helped in the discovery of galaxy cluster XMMXCS 2215-1738, which is 10 billion light-years from Earth. It also measured the spin frequency of a supermassive black hole, located at the core of NGC 1365 among other things. As of 2018, around 5600 research papers have been published either about XXM-Newton or its results.
Spektr – R
Funded by Astro Space Center, Spektr – R, a Russian scientific satellite is a part of the RadioAstron program with a radio telescope aboard. On 18 July 2011, the satellite was launched from Baikonur Cosmodrome to conduct research on the dynamics and structure of radio sources in our universe. Due to equipment failure, the craft last contacted the ground floor on 11 January 2019. Finally, on 30 May 2019, the spacecraft operations ended and the mission was announced finished.
Hard X-ray Modulation Telescope
Hard X-ray modulation telescope or Insight – HXMT is China’s first X-ray satellite that was launched on 15th June 2017. The telescope has the capability of ‘all-sky monitoring’ along with reconstructing the scanned images of the sky region. The satellite’s mission was to observe neutron stars, black holes, active galactic nuclei, and other celestial objects based on their gamma-ray and X-ray emissions. Also, it was a joint collaboration between the Chinese Academy of Sciences, Tsinghua University, and Ministry of Science and Technology of China that had been in development since the year 2000.
NuSTAR
Nuclear Spectroscopic Telescope Array (NuSTAR) or SMEX-11 or Explorer-93 is an X-ray telescope based in space that instead of using a Wolter telescope, uses a conical approximation. It is the 11th mission in NASA’s Small Explorer satellite program, hence the name SMEX-11. The initial launch date was 21 March 2012, which was later postponed to 13 June 2012 due to software issues. The telescope’s main task was to find black holes that were a billion times massive than our home star and study the supernova remnants in the universe.
Hitomi
Hitomi (“pupil of the eye” in Japanese) is the 6th X-ray satellite by ISAS and JAXA, previously named ASTRO-H, was launched at Japan’s Tanegashima Space Center on 17th February 2016. Equipped with gamma rays to soft X-rays, the astronomy satellite’s scientific objectives were to survey the behavior of dark matter in gravitational fields, study the physics behind particle jets and evolution of the universe including many others. However, JAXA lost communication with the spacecraft on March 26, 2016, and had to destroy the mission.
Spektr-RG
Preceded by Spektr-R, Spektr-RG is a high energy astrophysics observatory operated jointly by Russian Space Research Institute and German Aerospace Center. It has also been named Spectrum-X-Gamma, SXG, and SRG in the past and was launched on 13 July 2019 on a Proton-M rocket from Baikonur Site 81/24. The concept of this mission was first published in 2005. It took 14 years to construct, integrate, and test the mission before it was launched.
Astrosat
ISRO has been around for half a century now and has several successful space missions under its belt. In 2015, they launched their first multi-wavelength space telescope with a scientific focus on estimating the magnetic fields of neutron stars and detect new and bright X-ray sources in the universe. Another scientific objective of Astrosat is performing a deep field survey in the Ultraviolet region in the Universe. Launched on September 28, 2015, it has been 4 years and 8 months since the mission started.
Chandra X-ray Observatory
Named after Indian-American astrophysicist Subrahmanyan Chandrasekhar, Chandra X-ray Observatory is a flagship-class X-ray space telescope, which was launched in July 1993 on board with Space Shuttle Columbia. Chandra is 100 times more sensitive to X-ray sources than any other X-ray telescope and is the world’s most powerful X-ray telescope. The entire mission cost NASA about 165 crore USD. Talking about all the scientific discoveries made by the telescope will take a long time. However, two of the most important discoveries include capturing the first light image of Cassiopeia A’s supernova remnant and discovering a never seen ring around the pulsar, which had only been seen partially in the past.
