词条 | X-ray astronomy satellite |
释义 |
An X-ray astronomy satellite studies X-ray emissions from celestial objects, as part of a branch of space science known as X-ray astronomy. Satellites are needed because X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. A detector is placed on a satellite which is then put into orbit well above the Earth's atmosphere. Unlike balloons, instruments on satellites are able to observe the full range of the X-ray spectrum. Unlike sounding rockets, they can collect data for as long as the instruments continue to operate. For example, the Chandra X-ray Observatory has been operational for more than fifteen years. Active X-ray observatory satellitesSatellites in use today include the XMM-Newton observatory (low to mid energy X-rays 0.1-15 keV) and the INTEGRAL satellite (high energy X-rays 15-60 keV). Both were launched by the European Space Agency. NASA has launched the Swift and Chandra observatories. One of the instruments on Swift is the Swift X-Ray Telescope (XRT). The GOES 14 spacecraft carries on board a Solar X-ray Imager to monitor the Sun's X-rays for the early detection of solar flares, coronal mass ejections, and other phenomena that impact the geospace environment.[1] It was launched into orbit on June 27, 2009, at 22:51 GMT from Space Launch Complex 37B at the Cape Canaveral Air Force Station. On January 30, 2009, the Russian Federal Space Agency successfully launched the Koronas-Foton which carries several experiments to detect X-rays, including the TESIS telescope/spectrometer FIAN with SphinX soft X-ray spectrophotometer. ISRO launched the multi-wavelength space observatory Astrosat in 2015. One of the unique features of ASTROSAT mission is that it enables the simultaneous multi-wavelength observations of various astronomical objects with a single satellite. ASTROSAT observes universe in the optical, Ultraviolet, low and high energy X-ray regions of the electromagnetic spectrum, whereas most other scientific satellites are capable of observing a narrow range of wavelength band. The Italian Space Agency (ASI) gamma-ray observatory satellite Astro-rivelatore Gamma ad Imagini Leggero (AGILE) has on board the Super-AGILE 15-45 keV hard X-ray detector. It was launched on April 23, 2007, by the Indian PSLV-C8.[2] A soft X-ray solar imaging telescope is on board the GOES-13 weather satellite launched using a Delta IV from Cape Canaveral LC37B on May 24, 2006.[3] However, there have been no GOES 13 SXI images since December 2006. Although the Suzaku X-ray spectrometer (the first micro-calorimeter in space) failed on August 8, 2005, after launch on July 10, 2005, the X-ray Imaging Spectrometer (XIS) and Hard X-ray Detector (HXD) are still functioning. Past X-ray observatory satellitesPast observatories include SMART-1, which contained an X-ray telescope for mapping lunar X-ray fluorescence, ROSAT, the Einstein Observatory (the first fully imaging X-ray telescope), the ASCA observatory, EXOSAT, and BeppoSAX. Uhuru was the first satellite launched specifically for the purpose of X-ray astronomy. Copernicus which carried an X-ray detector built by University College London's Mullard Space Science Laboratory made extensive X-ray observations. ANS could measure X-ray photons in the energy range 2 to 30 keV. Ariel 5 was dedicated to observing the sky in the X-ray band. HEAO-1 scanned the X-ray sky over 0.2 keV - 10 MeV. Hakucho was Japan's first X-ray astronomy satellite. ISRO's IRS-P3 launched in 1996 with the Indian X-ray Astronomy Experiment (IXAE) on board which aimed to study the time variability and spectral characteristics of cosmic X-ray sources and for detection of transient X-ray sources. IXAE instruments consisted of three identical pointed mode proportional counters (PPCs) operated in the energy range 2-20 keV, FOV of 2° x 2° and effective area of 1200 cm2, and an X-ray sky monitor (XSM) operating in the energy range 2-10 keV. Array of low-energy X-ray imaging sensorsThe Array of Low Energy X-ray Imaging Sensors (ALEXIS) featured curved mirrors whose multilayer coatings reflect and focus low-energy X-rays or extreme ultraviolet light the way optical telescopes focus visible light. The launch of ALEXIS was provided by the United States Air Force Space Test Program on a Pegasus Booster on April 25, 1993. The spacing of the molybdenum (Mo) and silicon (Si) layers on each telescope's mirror is the primary determinant of the telescope's photon energy response function. ALEXIS operated for 12 yr. OSO-3The third Orbiting Solar Observatory (OSO 3) was launched on March 8, 1967, into a nearly circular orbit of mean altitude 550 km, inclined at 33° to the equatorial plane, deactivated on June 28, 1968, followed by reentry on April 4, 1982. Its XRT consisted of a continuously spinning wheel (1.7 s period) in which the hard X-ray experiment was mounted with a radial view. The XRT assembly was a single thin NaI(Tl) scintillation crystal plus phototube enclosed in a howitzer-shaped CsI(Tl) anti-coincidence shield. The energy resolution was 45% at 30 keV. The instrument operated from 7.7 to 210 keV with 6 channels. OSO-3 obtained extensive observations of solar flares, the diffuse component of cosmic X-rays, and the observation of a single flare episode from Scorpius X-1, the first observation of an extrasolar X-ray source by an observatory satellite. Among the extrasolar X-ray sources OSO 3 observed were UV Ceti, YZ Canis Minoris, EV Lacertae and AD Leonis, yielding upper soft X-ray detection limits on flares from these sources.[4] ESRO 2B (Iris)ESRO 2B (Iris) was the first successful ESRO satellite launch. Iris was launched on May 17, 1968, had an elliptical orbit with (initially) apogee 1086 km, perigee 326 km, and inclination 97.2°, with an orbital period of 98.9 minutes. The satellite carried seven instruments to detect high energy cosmic rays, determine the total flux of solar X-rays, and measure trapped radiation, Van Allen belt protons and cosmic ray protons. Of special significance for X-ray astronomy were two X-ray instruments: one designed to detect wavelengths 1-20 Å (0.1-2 nm) (consisting of proportional counters with varying window thickness) and one designed to detect wavelengths 44-60 Å (4.4-6.0 nm) (consisting of proportional counters with thin Mylar windows).[5]Wavelength dispersive X-ray spectroscopy (WDS) is a method used to count the number of X-rays of a specific wavelength diffracted by a crystal. WDS only counts X-rays of a single wavelength or wavelength band. In order to interpret the data, the expected elemental wavelength peak locations need to be known. For the ESRO-2B WDS X-ray instruments, calculations of the expected solar spectrum had to be performed and were compared to peaks detected by rocket measurements.[6]Other X-ray detecting satellites
Proposed (future) X-ray observatory satelliteseROSITA and ART-XCAmong the contracts negotiated in August 2009 at the MAKS International Aviation and Space Salon there was an agreement signed by the Russian Federal Space Agency (Roscosmos) and the German Aerospace Center (DLR). The contract details the creation of the Orbital Astrophysics Observatory Spectrum-X-Gamma (SXG) initially planned to be launched in 2012.[13] In May 2015 plans call for a 2016 launch.[14] {{As of|February 2016}} it is planned to launch in Sept 2017.[13] According to Mikhail Pavlinsky, deputy head of the Space Research Institute (SPI), the total project cost nears €50 million. Under the agreement, Germany will provide the main of the two X-ray telescopes (eROSITA), while Russia will install it on its platform, prepare the spacecraft, and take care of all related issues. Russia will also install an additional telescope (ART-XC) on this platform. The new observatory will help scientists perform an all-sky scan survey.[15] ATHENAAdvanced Telescope for High Energy Astrophysics was selected in 2013 as a second large mission of the Cosmic Vision programme.[16] It will be one hundred times more sensitive than the best of existing X-ray telescopes.[17]Solar OrbiterThe Solar Orbiter (SOLO) will approach to 62 solar radii to view the solar atmosphere with high spatial resolution in visible, XUV, and X-rays. The nominally 6 yr mission will be from an elliptical orbit around the Sun with perihelion as low as 0.28 AU and with increasing inclination (using gravity assists from Venus) up to more than 30° with respect to the solar equator. The Orbiter will deliver images and data from the polar regions and the side of the Sun not visible from Earth.[18] The launch date, if selected, could be Jan 2017. Astro-H2In July 2016 there were discussions between JAXA and NASA on launching a satellite to replace the Hitomi telescope lost in 2016. The launch goal is 2020.[19][20] International X-ray ObservatoryInternational X-ray Observatory (IXO) was a cancelled observatory. a result of the merging of NASA's Constellation-X and ESA/JAXA's XEUS mission concepts. It was planned to feature a single large X-ray mirror with a 3 m2 collecting area and 5" angular resolution, and a suite of instrumentation, including a wide field imaging detector, a hard X-ray imaging detector, a high-spectral-resolution imaging spectrometer (calorimeter), a grating spectrometer, a high timing resolution spectrometer, and a polarimeter. Constellation-XConstellation-X was early proposal that was superseded by IXO. It was to provide high resolution X-ray spectroscopy to probe matter as it falls into a black hole, as well as probe the nature of dark matter and dark energy by observing the formation of clusters of galaxies. See also
References1. ^{{cite web |title=GOES Solar X-ray Imager |url=http://www.swpc.noaa.gov/sxi/index.html}} 2. ^{{cite web|author=Wade M |title=Chronology - Quarter 2 2007 |url=http://www.astronautix.com/chrono/20072.htm |deadurl=yes |archiveurl=https://web.archive.org/web/20100118143515/http://astronautix.com/chrono/20072.htm |archivedate=January 18, 2010 }} 3. ^{{cite web |author=Wade M |title=Chronology - Quarter 2 2006 |url=http://www.astronautix.com/chrono/20062.htm}} 4. ^{{cite journal |author=Tsikoudi V |author2=Hudson H |title=Upper limits on stellar flare X-ray emission from OSO-3 |journal=Astronomy and Astrophysics|date=1975 |volume=44|page=273|bibcode=1975A&A....44..273T}} 5. ^{{cite web |title=The European Space Research Organization satellite 2B |url=http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/esro2b.html}} 6. ^{{cite journal |author=Mewe R |title=Calculations on the Solar Spectrum from 1 TO 60 Å |journal=Space Sci Rev|date=1972|page=666 |issue=4-6|doi=10.1007/BF00213502 |volume=13|bibcode = 1972SSRv...13..666M }} 7. ^1 {{cite web |author=Calderwood TD |title=Highlights of NRL's First 75 Years |url=http://www.nrl.navy.mil/NewsRoom/images/75highlights.pdf}} 8. ^{{cite web |author=Dick SJ |title=June 2005 |url=https://history.nasa.gov/chronologies/jun%202005.htm}} 9. ^{{cite journal |author=Hoff HA |title=Exosat - the new extrasolar X-ray observatory |journal=J Brit Interplan Soc |date=Aug 1983 |volume=36 |issue=8 |pages=363–7 |bibcode=1983JBIS...36..363H }} 10. ^1 {{cite web |title=The Sixth Orbit Solar Observatory (OSO-6) |url=http://imagine.gsfc.nasa.gov/docs/sats_n_data/missions/oso6.html}} 11. ^{{ cite journal|display-authors=6|author=Sheffer, E. K.|author2=Kopaeva, I. F.|author3=Averintsev, M. B.|author4=Bisnovatyi-Kogan, G. S.|author5=Golynskaya, I. M.|author6=Gurin, L. S.|author7=Dyachkov, A. V.|author8=Zenchenko, V. M.|author9=Kurt, V. G.|author10=Mizyakina, T. A.|author11=Mironova, E. N.|author12=Sklyankin, V. A.|author13=Smirnov, A. S.|author14=Titarchuk, L. G.|author15=Shamolin, V. M.|author16=Shafer, E. Y.|author17=Shmelkin, A. A.|author18=Giovannelli, F.|title=X-Ray Studies of the HERCULES-X-1 Pulsar with the Astron Satellite|journal=SOVIET ASTR.(TR: A. ZHURN.)|date=Jan–Feb 1992|volume=36|issue=1|pages=41–51|bibcode=1992SvA....36...41S}} 12. ^{{cite web|title=Lockheed Martin Press Release |url=http://www.lockheedmartin.com/news/press_releases/2008/4-30-polarsat.html |date=April 30, 2008 |deadurl=yes |archiveurl=https://web.archive.org/web/20090104024248/http://www.lockheedmartin.com/news/press_releases/2008/4-30-polarsat.html |archivedate=January 4, 2009 |df= }} 13. ^1 Spektr-RG to expand horizons of X-ray astronomy {{webarchive |url=https://web.archive.org/web/20110302085013/http://www.russianspaceweb.com/spektr_rg.html |date=March 2, 2011 }} 14. ^eROSITA, 26.05.2015 15. ^New X-Ray Telescopes Search for Galaxy Clusters and Massive Black Holes, 16.09.2009 16. ^{{Cite web | title = ESA's new vision to study the invisible universe| publisher = ESA | url = http://www.esa.int/Our_Activities/Space_Science/ESA_s_new_vision_to_study_the_invisible_Universe |accessdate = 8 February 2017}} 17. ^{{cite news|url=https://www.bbc.com/news/science-environment-28053831|title=Athena: Europe plans huge X-ray space telescope|first1=Jonathan|last1=Amos|publisher=BBC News|date=27 June 2014|accessdate=8 February 2017}} 18. ^{{cite web |title=ESA Science & Technology: Solar Orbiter |url=http://sci.esa.int/science-e/www/area/index.cfm?fareaid=45}} 19. ^{{cite web|last1=Foust|first1=Jeff|title=NASA may build replacement instrument for Japanese astronomy mission|url=http://spacenews.com/nasa-may-build-replacement-instrument-for-japanese-astronomy-mission/|website=SpaceNews|accessdate=13 August 2016}} 20. ^{{cite web|last1=Kruesi|first1=Liz|title=JAXA may remake its X-ray observatory Hitomi for a 2020 launch|url=http://www.astronomy.com/news/2016/07/jaxa-may-remake-its-x-ray-observatory-hitomi-for-a-2020-launch|website=Astronomy.com|accessdate=13 August 2016}} 4 : X-ray astronomy|Astronomical imaging|Space observatories|X-ray telescopes |
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