Автор che wi, 05.11.2016 13:28:35
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ЦитатаМежду тем, в ближайшие месяцы до конца 2016 года китайские ученые планируют осуществить запуск модуляционного телескопа жесткого рентгеновского диапазона HXMT (Hard X-ray Modulation Telescope).Предполагается, что данный аппарат произведет обзор небесной сферы в жестких рентгеновских лучах и, возможно, обнаружит примерно 1000 новых источников, включая активные галактические ядра, квазары и объекты галактического фона, а затем будет выполнять детальное исследование отдельных объектов, в числе которых черные дыры и нейтронные звезды.HXMT также будет осуществлять мониторинг иных интересных космических источников и проводить периодический обзор галактической плоскости.Впервые проект HXMT был предложен китайскими учеными еще в 1994 году. В апреле 2000 года он вошел в список основных государственных проектов в области фундаментальных исследований («проект 973»). В 2004 году был изготовлен наземный прототип HXMT и выполнены испытания прибора на аэростатах. Финансирование работ проводят Министерство науки и техники, Китайская академия наук и Университет Цинхуа.
ЦитатаThe Hard X-ray Modulation Telescope (HXMT) is China's first astronomical satellite. There are three main payloads onboard HXMT, the high energy X-ray telescope (20-250 keV, 5100 cm2), the medium energy X-ray telescope (5-30 keV, 952 cm2), and the low energy X-ray telescope (1-15 keV, 384 cm2). The main scientific objectives of HXMT are: (1) to scan the Galactic Plane to find new transient sources and to monitor the known variable sources, and (2) to observe X-ray binaries to study the dynamics and emission mechanism in strong gravitational or magnetic fields.
Цитатаche wi пишет: Цитата... модуляционного телескопа жесткого рентгеновского диапазона HXMT (Hard X-ray Modulation Telescope).
Цитата... модуляционного телескопа жесткого рентгеновского диапазона HXMT (Hard X-ray Modulation Telescope).
ЦитатаHXMT to launch in June with two Zhuhai-1 video microsatellites for the Orbita system.Launch vehicle is a CZ-4B.
Цитата ChinaSpaceflight @cnspaceflight 9 ч. назад【珠海一号】欧比特称两颗视频试验卫星预计搭载硬X射线调制望远镜主卫星发射任务，由长征四号B型火箭执行发射任务。https://goo.gl/I8qsi8
Цитата[Zhuhai One] OBB said two video test satellites are expected to carry hard X-ray telescope main satellite launch mission, by the Long March IV B rocket execution mission.
ЦитатаOu Bite: The company's two video test satellites are expected to carry a hard X-ray telescope main satellite launch mission, carried out by the Long March IV B rocket launch mission. The company has been to communicate with the launch unit, for the middle of June in Jiuquan launch site to complete the first two video test satellite carrying launch mission.
ЦитатаПекин, 29 мая /Синьхуа/ -- Китай планирует запустить новую космическую обсерваторию для исследования многих загадок Вселенной, включая активные ядра галактик на краю Вселенной.Ученые обнаружили, что в центре почти всех галактик имеется сверхмассивная черная дыра, масса которой в миллионы и даже миллиарды раз превышает массу Солнца. Согласно закону всемирного тяготения сверхмассивная черная дыра активно поглощает близлежащие пыль и газ.Когда черная дыра поглощает слишком много, избыточное вещество превращается в две релятивистские струи, перпендикулярные аккреционному диску черной дыры.Релятивистские струи и аккреционный диск сверхмассивной черной дыры генерируют мощное рентгеновское излучение, которое способно преодолеть расстояние в несколько миллиардов световых лет. Эти галактики имеют очень яркие ядра, настолько яркие, что центральная область может быть более освещенной, чем вся остальная часть галактики. Такие ядра называют активными ядрами галактик.Разработанный китайскими учеными телескоп для работы с жестким рентгеновским излучением /Hard X-ray Modulation Telescope, HXMT/ предназначен для наблюдения за некоторыми активными ядрами галактик."Активные ядра галактик находятся очень далеко от Земли, поэтому наш телескоп может зондировать только самые яркие из них", - рассказал научный руководитель проекта HXMT, заведующий ключевой лабораторией физики элементарных частиц и астрономии Академии наук Китая Чжан Шуаннань.Ученые пока не знают, как сверхмассивные черные дыры образуются и развиваются, что является ключом к пониманию эволюции галактик.Ожидается, что HXMT поможет ученым наблюдать за ядерным диапазоном, находящимся близко от горизонта событий сверхмассивных черных дыр в центре активных галактик, и собрать информацию о чрезвычайно сильных гравитационных полях, сообщил Чжан Шуаннань.
ЦитатаSINCE the detection of gravitational waves, scientists have been eager to find corresponding electromagnetic signals. This will be an important task for China's space telescope, the Hard X-ray Modulation Telescope, due to launch this year. Скрытый текст: Gravitational waves are "ripples" in the fabric of spacetime caused by some of the most violent and energetic processes in the universe. Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity.He showed that massive accelerating objects, such as neutron stars or black holes orbiting each other, would disrupt spacetime in such a way that "waves" of distorted space would radiate from the source, like ripples from a stone thrown into a pond.These ripples would travel at the speed of light through the universe, carrying with them information about their origin, as well as clues to the nature of gravity itself.The strongest gravitational waves are produced by events such as colliding black holes, supernova explosions, coalescing neutron stars or white dwarf stars, the slightly wobbly rotation of neutron stars that are not perfect spheres, and the remnants of gravitational radiation created by the birth of the universe itself.On February 11 last year, the Laser Interferometer Gravitational-Wave Observatory in the United States announced the first observation of gravitational waves. On June 15 the same year, the second detection of a gravitational wave event from colliding black holes was announced.Increased reliabilityXiong Shaolin, a scientist at the Institute of High Energy Physics of the Chinese Academy of Sciences, says the position accuracy of all the gravitational wave events detected so far is still poor.If scientists can find electromagnetic signals happening at similar positions and times of the gravitational wave events, it will increase the reliability of the detection, he said. Combined analysis of the gravitational wave and electromagnetic signals will help reveal more about the celestial bodies emitting the waves.Scientists have yet to detect electromagnetic signals corresponding to gravitational waves. Many scientists would regard detecting gravitational waves and corresponding electromagnetic signals as a major scientific discovery. Some suspect that mysterious gamma-ray bursts could be electromagnetic signals corresponding to gravitational waves.Brightest eventsGamma-ray bursts are extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe. Bursts can last from several milliseconds to more than an hour.The intense radiation of most observed gamma-ray bursts is believed to be released by a supernova as a rapidly rotating, high-mass star collapses to form a neutron star or black hole. A subclass of bursts appears to originate from a different process: the merger of binary neutron stars, or the merger of a neutron star and a black hole.About 0.4 seconds after the first gravitational event was detected on September 14, 2015, NASA's Fermi Gamma-Ray Space Telescope detected a relatively weak gamma-ray burst, which lasted about a second.But scientists disagree on whether these two events are related, and no other gamma-ray burst probe detected a gamma-ray burst. Scientists need more evidence to clarify the relationship between gamma-ray bursts and gravitational waves.Zhang Shuangnan, lead scientist of HXMT and director of the Key Laboratory of Particle Astrophysics of CAS, said: "Since gravitational waves were detected, the study of gamma-ray bursts has become more important. In astrophysics research, it's insufficient to study just the gravitational wave signals. We need to use the corresponding electromagnetic signals, which are more familiar to astronomers, to facilitate the research on gravitational waves."HXMT's effective detection area for monitoring gamma-ray bursts is 10 times that of the Fermi space telescope. "HXMT can play a vital role in searching for electromagnetic signals corresponding to gravitational waves," says Zhang."If HXMT can detect the electromagnetic signals corresponding to gravitational waves, it would be its most wonderful scientific finding."
ЦитатаHXMT - Hard X-Ray Modulation TelescopeImage: Xinhua/SASTINDThe Hard X-Ray Modulation Telescope (HXMT) is a Chinese X-Ray Space Observatory launching in 2017 as the country's prime X-ray astronomy mission to observe black holes, neutron stars and other intense X-ray and gamma-ray sources to study the high-energy universe.A project of several institutes in China, HXMT hosts three collimated X-ray telescopes tasked with a full scan of the Galactic Plane to find new transient X-ray sources, monitor known sources, and to observer X-ray binaries to study dynamic phenomena in intense gravitational and magnetic fields. Скрытый текст: The 2.8-metric-ton observatory has had an extraordinarily long road to launch, first proposed in 1993 and sel ected for further study in 2000 to advance to the development stage with an initial plan of launching in 2010. However, these plans could not be realized and HXMT ended up requiring funding under three of China's Five-Year Plans as the project evolved through the addition of payloads and optimization for the working conditions found in Low Earth OrbitPhoto: IHEPThe mission's design was eventually frozen in 2011 when approval was given for the project to enter into hardware manufacture, starting with the fully functional ground testbed before the flight unit began assembly after 2012.Part of the HXMT Project are the Chinese Ministry of Science and Technology, the Chinese Academy of Sciences, Tsinghua University and satellite platform builder CAST. According to the HXMT Project, the Institute of High Energy Physics at CAS and Tsinghua University were responsible for the development of the Payload Module while CAST designed the satellite platform - reportedly based on heritage fr om the Ziyuan-2 Earth Observation Satellites which were based on high-resolution military imaging satellites and used the Phoenix-Eye-2 satellite bus.The Ziyuan-2 satellites were among the largest and heaviest Chinese satellites when being launched between 2000 and 2004, hosting medium-resolution imaging payloads to capture Earth imagery at a 3-meter ground resolution. Ziyuan-2 entered development in 1993, the same year HXMT was first proposed, providing a connection between the platform and mission.Image: CASTPhoenix Eye-2, optimized for operation in Low Earth Orbit, can have launch masses in excess of 2,600 Kilograms featuring two three-panel solar arrays, a three-axis attitude determination and control platform for precise pointing, and a propulsion system consisting of orbit correction engines and attitude control thrusters.The HXMT satellite measures 2.0 by 2.0 by 2.8 meters in size and has a launch mass of 2,800 Kilograms with the payload making up more than one metric ton of the satellite's initial mass. According to the project, HXMT provides excellent three-axis stabilization with a control precision of +/-0.1 degrees, pointing knowledge better than 0.01° and attitude stability of 0.005°/sec. The payload module is 1.9 by 1.65 by 1.0 meters in size.HXMT carries three main payloads, all slat-collimated X-ray telescopes that cover different energy ranges to create a system that can deliver high-resolution images and spectral data over a broad energy range.HXMT Payload Section - Image: CAS/HXMT ProjectThe biggest of the three is the high-energy X-ray telescope (HE) that covers an energy range of 20 to 250 kilo-electronvolt and has a large active area of 5,100cm². ME, the medium-energy X-ray telescope, covers energies of 5 to 30 keV with an active area of 952cm2, and the 384cm² low-energy X-ray telescope (LE) is sensitive for X-rays between 1 and 15keV. Additionally, HXMT hosts a CsI detector to detect gamma-ray bursts.The typical field of view of HXMT's aligned telescopes is 1° x 6° with additional fields of view toward other directions in order to obtain measurements of the cosmic X-ray background.HXMT will be tasked with two different types of measurements - an all-sky survey around the Galactic Plane and focused observations on objects of interest to obtain their broad band spectra and multi-wavelength temporal properties. The sky survey is intended to discover new X-ray sources including transient objects that are of particular interest for further scrutiny.Image: HXMT ProjectSpecifically, HXMT aims to conduct measurements on various types of Active Galactic Nuclei (AGNs, supermassive black holes) to help understand the nature of the cosmic X-ray background.The mission will also study the quasi-periodic oscillation and other time-constrained phenomena of black holes and neutron star X-ray binaries, taking advantage of the telescope's large active area that allows for the study of short time-scale variability. Observations will also me made to examine the cyclotron resonance features and the magnetic field strength of ultra-dense neutron stars and remnants of supernova explosions will be studied for their non-thermal X-ray emission properties and mechanisms of particle acceleration.HXMT stands out among other X-ray missions for its combination of high-angular resolution, time resolution and spectral resolution as well as its multi-use capability for all-sky scans and narrow-field pointed observations. Its method of direct demodulation to reconstruct X-ray images at high angular resolution is also a novelty in space-based X-ray astronomy.Image: HXMT ProjectOne unique aspect of the HXMT mission is the ability to rapidly target transient sources. As part of its scan of the Galactic Plane, the telescope is expected to detect a number of new transient sources as well as X-Ray binaries in their high-emission state.A quick-look software algorithm will analyze scanning data collected every day and identify the position and flux of transient sources. When a source of interest is found, pointed observations can be put into the spacecraft's operational plan within 24 hours of the first detection to capture valuable data.The High-Energy X-Ray Telescope (HE) comprises 18 NaI/CsI phoswich detectors arranged in the central section of the Payload Module using two concentric circles with six elements in the inner circle and 12 elements in the outer circle.Image: HXMT ProjectPhoswich elements, short for phosphor sandwich, employ a combination of different scintillating materials which absorb the energy of an incoming X-ray or gamma-ray photon and re-emit the energy in the form of light which can be measured using conventional photo-detectors. In a phoswich, two scintillators with different pulse shape characteristics are optically coupled and interface with a photo-multiplier. Analysis of the pulse shape is used to distinguish signals fr om the two scintillators to identify the scintillator in which the event occurred.The advantage of phoswich detectors comes in the measurement of low-energy gamma- and X-rays as well as measurements in a higher-background environment.In HXMT's case, the scintillators are Sodium Iodide doped with Thallium and Caesium Iodide doped with Sodium. Each phoswich crystal element is 19 centimeters in diameter, the 3.5mm thick NaI crystal lies directly behind a Beryllium window and the 40mm CsI crystal is located underneath the NaI. The full energy of an incident X-ray is deposited into the NaI crystal while the CsI is used as active shielding to reject events fr om the back side.HE Detector Element - Image: HXMT ProjectImage: HXMT ProjectEach of the 18 HE detector elements have an active area of 283.5cm² and in front of the detectors themselves reside Tantalum & Tungsten collimators that set the field of view for each detector.Fifteen of the detectors have a field of view of 1.14 by 5.71 degrees, two have a larger 5.71 by 5.71-degree FOV for background detection and the final element is fully blocked with a 2mm tantalum shield for dark current measurements. The overall active instrument FOV is 5.71 by 5.71 degrees. Surrounding the detector assemblies on all sides except the optical axis are scintillating plastic plates that act as veto to depress events caused by particles not arriving on the instrument's optical axis.Underneath the phoswich stack is a quartz separator that couples the scintillator to the Photomultiplier tube in which the visible radiation photons are converted into electrons which can produce an electrical signal that can me measured. Photomultipliers make use of the photoelectric effect, creating free electrons when photons strike the photocathode element. The electrons are directed through an electron multiplier that comprises a series of dynodes wh ere secondary emission takes place to create sufficient electrons to produce a measurable current.[HXMT Instrument Package - Image: HXMT ProjectHE is capable of simultaneous spectral measurements, timing and imaging. Also, the instrument is capable of doubling as a gamma-ray detector, sensitive in an energy range of 40 to 600 keV in normal operations mode and 200 keV to 2 MeV when in GRB mode. In this mode, the instrument will be important for observations of Gamma-ray burst spectra and the search for the electro-magnetic counterpart to gravitational waves which have only recently been proven to be a real concept.Each of the 18 high-energy X-ray telescopes has its own high-gain controller, installed in the corresponding collimator grid and adjusting the photo-detector voltage in real time to keep a stable detector gain.Three particle monitors installed on the instrument deck are in charge of measuring the influx of high-energy protons and electrons. If charged particle flux is higher than a programmed threshold, the high voltages of the detectors will be automatically decreased to avoid damaging the photomultiplier tubes. An additional requirement for HE is a stable thermal environment, requiring the detector assemblies to be maintained at 18°C +/-1°C.Image: CASHE hosts a central electronics box that is responsible for providing the high-voltage power supply to the detectors and accept amplified signals from all detectors and anti-coincidence monitors. Data from the instrument is delivered to the satellite platform through LVDS high-speed interfaces and a 1553 data bus is used for relaying housekeeping telemetry to the satellite and accepting commands for instrument actuation. The electronics box also receives a pulse-per-second signal for time synchronization as well as a 5 MHz signal from an ultra-stable oscillator to provide the precise timing needed for X-ray measurements.Testing of the flight model of HE showed the NaI scintillators can make measurements in an energy range of 16-350 keV when the instrument operates in normal mode while the CsI in GRB mode can detect gamma-rays at energies of 130 keV to 3 MeV. (In normal mode, NaI events are good events and in GRB mode, only CsI events are good events.) HE achieves a source location accuracy of under 1 arcmin, an angular resolution better than 5 arcmin and a time resolution better than 25µs.ME Structure - Image: HXMT ProjectThe Medium-Energy X-Ray Telescope uses a total of 1,728 Silicon-PIN diodes as detectors, facilitated in three modules installed on the optical bench of the HXMT observatory and creating a total active area of 952cm², sensitive in the 5-30 keV range.ME also hosts three different Fields of View - the main FOV is 1 x 4° to capture data on targets, the broad FOV for background measurements is 4 x 4° and a fully blocked detector group provides dark current measurements for calibration.The large number of PIN diodes actively gathering data requires an elaborate read out system using 54 Application Specific Integrated Circuits.ME Detector Box - Image: HXMT ProjectME employs a layered architecture with the Main Electronics Box at the top, interfacing via high-speed LVDS with the three Detector Boxes containing six Modules, each reading out 32 Si-PIN pixels. Four pixels are facilitated in one ceramic package (active area of 56.25mm² each), creating a total of 432 pixel units installed on ME. The data acquisition circuit is controlled by Field Programmable Gate Arrays, allowing the acquisition to be tweaked during the mission.The 32-channel ASIC chips form the central part of the read-out chain and are in charge of collecting raw signals from the pixels, amplifying the electrical signals, digitizing the output and transmitting the pre-processed signal to the Main Electronics Box. The use of ASIC technology allows ME to operate at a very high time resolution of 255µs.Collimators atop each pixel set its field of view and all pixels are connected to active thermal control systems to maintain a temperature of -5 to -50 degrees Celsius to lim it the effects of dark currents.LE Detector Box - Image: HXMT ProjectThe Low-Energy X-Ray Detector (LE) is focused on sky survey and pointed observations in the soft X-ray range of 0.7 to 15 keV. It is different from the detectors on Chandra and XMM-Newton that cover a similar energy range but use grazing incidence optics. Instead, HXMT utilizes collimators to shield the photons outside the field of view.LE comprises three detector boxes holding Swept Charge Devices that work in a continuous read-out mode, recording the energy and arrival time of incident photons to achieve a higher time resolution than traditional CCD detectors which collect photons over a pre-programmed exposure time. With its good energy and exceptional time resolution, LE is expected to make a significant contribution to X-ray astronomy.The LE instrument hosts three identical detector boxes installed on the +Z side of the main payload section and a central electronics box within the payload module. The three boxes, similar to ME, are installed with an angle of 120 degrees to each other to enable the modulation of the signals from the three boxes to extract the image information through a restoration technique like direct demodulation.LE Detector Elements - Image: HXMT ProjectThe Swept Charge Devices (SCDs) have the ability to convert the energy of an incident soft-X-ray photon into electric signals that are proportional to that photon's energy. These electric signals are transmitted to the electronics box wh ere they are converted to a digital representation including the event energy and arrival time. Payload data is sent to the spacecraft via LVDS and commanding / housekeeping data exchange is completed through a 1553 link.Within each detector box are eight collimators that set the field of view for each corresponding detector unit of 2×2 pixels, making for a total of 32 SCD chips per detector box and 96 in total for an active area of 384cm². Optical blocking filters, remainder-proof films and thermal support systems like heat pipes are also facilitated within each detector box. The electronics for each box reside directly beneath it to accept the raw signals fr om the individual pixels for amplification, digitization and time-tagging.Image: HXMT ProjectLE employs pointing observation and survey collimators with combined wide (4 x 6°) and narrow (1.6 x 6°) FOVs plus blocked pixels for background measurements and an All-Sky Monitoring collimator creates a 50~60° x 2~6° Field Of View for one pixel array per detector to support the all-sky survey that is a core objective of the HXMT mission. Of the 32 SCD pixels in each detector box, 20 have narrow FOVs, six have wide FOVs, four are All-Sky Monitor pixels and two are blocked detectors acting as calibration sources.LE achieves an energy resolution of 140 eV and a time resolution of 1ms. Its detectors are maintained between -30 and -80°C.HXMT will operate in an orbit of 550 Kilometers at an inclination of 43 degrees, designed for the mission's observation objectives and to reduce the overall radiation influx to reduce backgrounds.
ЦитатаЦзюцюань, 15 июня /Синьхуа/ -- В четверг утром Китай запустил свой первый рентгеновский космический телескоп для наблюдения за черными дырами, пульсарами и гамма-всплесками. Телескоп был выведен на орбиту ракетой-носителем "Long March - 4B" /"Чанчжэн - 4Б"/, запущенной с космодрома Цзюцюань /пров. Ганьсу, Северо-Западный Китай/.
ЦитатаЦзюцюань, 15 июня /Синьхуа/ -- В четверг в 11:00 Китай запустил свой первый рентгеновский космический телескоп для наблюдения за черными дырами, пульсарами и гамма-всплесками.2,5-тонный рентгеновский телескоп "Insight" был выведен на орбиту на высоте 550 км над поверхностью Земли ракетой-носителем "Long March - 4B" /"Чанчжэн - 4Б"/, запущенной с космодрома Цзюцюань, расположенного в пустыне Гоби на северо-западе Китая.Телескоп поможет ученным лучше изучить эволюцию черных дыр, мощные магнитные поля и внутреннюю часть пульсаров.С его помощью ученые также намереваются изучить способы использования пульсаров для навигации космических кораблей, а также отыскать гамма-всплески, соответствующие гравитационным волнам.Как ожидается, благодаря усилиям нескольких поколений китайских ученных, телескоп "Insight" будет содействовать развитию космической астрономии и технологий зондирования с помощью рентгеновских лучей в Китае.
Цитатаche wi пишет: телескоп "Insight"