User:Marshallsumter/Radiation astronomy2/X-rays/Quiz

X-ray astronomy is a lecture for the radiation astronomy courses on the principles of radiation astronomy and X-ray astronomy.

You are free to take this quiz based on X-ray astronomy at any time.

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Quiz
{True or False, Whenever "X-ray" is used in a sentence where the context refers to X-radiation, the "X" is always supposed to be capitalized. + TRUE - FALSE
 * type=""}

{Which of the following is not a characteristic of X-radiation? - throwing a beam - a stream of charged or neutral rays + calculating the energy of a beam - sending out a traveling ray - a secondary-object hazard
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with the Sun? - a core which emits neutrinos - a solar wind which emanates out the polar coronal holes - gravity - the barycenter for the solar system - polar coronal holes + coronal clouds - its position + temperatures at or above 1 MK
 * type="[]"}

{Natural X-ray sources emit, reflect, fluoresce, or { transmit (i) }.
 * type="{}"}

{Complete the text: X-ray astronomy consists of three fundamental parts: 1. { logical laws (i) } with respect to incoming X-rays, or X-radiation, 2. { natural X-ray sources (i) }, and 3. the { sky (i) } and associated { realms (i) } with respect to X-rays.
 * type="{}"}

{Yes or No, X-rays span approximately three decades in wavelength, frequency, and energy. + Yes - No
 * type=""}

{Which of the following is not a characteristic of X-radiation? - electromagnetic radiation - ionizing radiation - emitted by a few atomic nuclei + occurs when a positron and an electron annihilate each other - only penetrates so far into a gaseous-objects atmosphere
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with the Sun? - a chromosphere which emits neutrinos + coronal loops that are particle accelerator-like + synchrotron radiation - a photosphere - a polar diameter that exceeds ever so slightly the equatorial diameter at solar cycle minimum + a polar temperature inside two radii of 1 MK + hot active regions with temperatures hot enough to fuse hydrogen - sunspots at the feet of coronal loops
 * type="[]"}

{The darker regions in X-rays at the North and South poles of the Sun are coronal holes, where the magnetic field lines are { open (i) }.
 * type="{}"}

{Complete the text: The photosphere of the Sun has an effective temperature of { 5778 K|5,778 K (i) } yet its corona has an average temperature of { 1-2 MK|1-2 x 106 K (i) }. The high temperature of the corona shows that it is heated by something other than direct { heat conduction (i) } from the photosphere.
 * type="{}"}

{True or False, Super soft X-ray sources are in most cases only detected below 0.5 keV. + TRUE - FALSE
 * type=""}

{Which of the following is not a characteristic of super soft X-radiation? - electromagnetic radiation - ionizing radiation - usually hidden by interstellar absorption in the galactic disk - readily evident in external galaxies + have energies in the 0.09 to 2.5 keV range
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with stellar surface fusion? + luminosities below ~3 x 1038 erg/s + a few SSS with luminosities ≥1039 erg/s + synchrotron radiation - a photosphere - a polar diameter that exceeds ever so slightly the equatorial diameter at solar cycle minimum + super soft X-rays + hot active regions with temperatures hot enough to fuse hydrogen - sunspots at the feet of coronal loops
 * type="[]"}

{Intragalactic super soft X-ray sources may be heavily reddened by { interstellar material|interstellar matter (i) }
 * type="{}"}

{Complete the text: Both { fusion|fusion- (i) } and { accretion|accretion- (i) } powered cataclysmic { variables (i) } have been observed to be X-ray sources.
 * type="{}"}

{True or False, Theorists try to generate or modify models to take into account new data. + TRUE - FALSE
 * type=""}

{Which of the following is not a characteristic of theoretical X-radiation astronomy? - a theory for any natural X-ray source + X-ray generation - theoretical X-ray emission - analytical models - computational numerical simulations
 * type=""}

{Which of the following are theoretical X-ray astronomy phenomena associated with astrophysics? + a thermal plasma mechanism + idea of a close binary + synchrotron radiation + high-density wind extinction - a polar diameter that exceeds ever so slightly the equatorial diameter at solar cycle minimum - super soft X-rays - hot active regions with temperatures hot enough to fuse hydrogen - sunspots at the feet of coronal loops
 * type="[]"}

{X-ray emission dividing lines may be explained by low transition region densities leading to low emission in { coronae (i) }
 * type="{}"}

{Complete the text: X-ray emission dividing lines may be explained by changes in a { magnetic (i) } field { structure (i) } to that of an { open (i) } topology, leading to a decrease of magnetically confined { plasma (i) }.
 * type="{}"}

{True or False, An entity in X-ray astronomy is either an X-ray source or an X-ray object. - TRUE + FALSE
 * type=""}

{Which of the following is not a characteristic of an entity in X-ray astronomy? - a theory for any natural X-ray source - X-ray generation - X-ray reflection + an analytical constant - a common or ancient name
 * type=""}

{Which of the following are X-ray astronomy phenomena associated with an entity? + a thermal plasma mechanism + a close binary + synchrotron radiation + high-density wind extinction - a polar diameter that exceeds ever so slightly the equatorial diameter at solar cycle minimum + super soft X-rays + hot active regions with temperatures hot enough to fuse hydrogen - sunspots at the feet of coronal loops
 * type="[]"}

{An entity in X-ray astronomy may be a researcher who turns on an X-ray generator to study X-ray emission, { absorption|reflection|transmission|fluorescence (i) }.
 * type="{}"}

{Complete the text: The X-ray luminosity of the { dominant (i) } group is an order of { magnitude (i) } fainter than that of the X-ray { jet (i) }.
 * type="{}"}

{True or False, An error circle on the celestial sphere about a detected X-ray source is an X-ray object. - TRUE + FALSE
 * type=""}

{Which of the following is not a characteristic of an entity in X-ray astronomy? - a theory for any natural X-ray source + produces refereed journal articles on the CGB - X-ray generation - X-ray reflection - a common or ancient name
 * type=""}

{Which of the following are X-ray astronomy phenomena associated with an entity? + discovers an X-ray source in Scorpius + a control group + synchrotron radiation - intergalactic medium - a polar diameter + super soft X-rays - hot active regions - sunspots at the feet of coronal loops
 * type="[]"}

{An entity in X-ray astronomy may be a researcher who turns on an X-ray generator to study X-ray { absorption|emission|reflection|transmission|fluorescence (i) } aboard the International Space Station.
 * type="{}"}

{Complete the text: Ultraluminous X-ray sources (ULXs) are { pointlike|point-like (i) }, nonnuclear X-ray sources with { luminosities (i) } above the { Eddington (i) } limit.
 * type="{}"}

{True or False, Some cosmic-ray observatories also look for high energy gamma rays and X-rays. + TRUE - FALSE
 * type=""}

{True or False, As gamma rays are defined to be radiation emitted from radionuclides, there are no radionuclides that emit X-rays. - TRUE + FALSE
 * type=""}

{True or False, A small amount of aluminum-26 is produced by collisions of magnesium atoms with cosmic-ray protons. - TRUE + FALSE
 * type=""}

{True or False, Aluminum-26 is generally distributed out of the plane of the Milky Way. - TRUE + FALSE
 * type=""}

{True or False, Aluminum-26 decays by either beta-plus or electron capture. + TRUE - FALSE
 * type=""}

{Which of the following is not a characteristic of a meteor in X-ray astronomy? - a detection of iron or nickel - determination of quantitative proportions - X-ray reflection - X-ray scattering + a meteorite impact site
 * type=""}

{Which of the following is not a characteristic of the diffuse X-ray background? + a higher intensity than the CMB - isotropic X-ray flux - a wide range of energies - a general increase in intensity from the Galactic plane to the poles - a thermal emission at the lowest energies
 * type=""}

{Which of the following is not a characteristic of the X-ray continuum? + Bragg peaks - may arise from an X-ray jet - may arise from the coronal cloud of an accretion disc - a power-law spectrum - a thermal emission at the lowest energies
 * type=""}

{Which of the following is not a characteristic of X-rays associated with neutron stars? - X-ray jets - X-ray binary + emission peaks indicative of neutron decay - X-ray burster - a low-mass X-ray binary
 * type=""}

{Which of the following is not a characteristic of X-rays associated with atomic number? - emission lines + X-ray continuum - unique atomic structure - creating an electron hole - discrete energy levels
 * type=""}

{Which of the following are X-ray astronomy phenomena that may be associated with a superluminal? + loops and rings in the X-ray emitting gas + an X-ray source + synchrotron radiation + Cherenkov radiation - signals with a velocity above c + super soft X-rays + hot active regions with temperatures hot enough to fuse hydrogen - starspots
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with the Earth? + lightning - Van Allen radiation belts + electrons striking the ionosphere + the geocorona - ice cores - meteorites - diffuse X-ray background - hurricanes
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with Mercury? - lightning + surface composition - electrons striking the ionosphere - a geocorona + minerals high in magnesium + surface sulfur enrichment - diffuse X-ray background + low-oxygen conditions
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with comets? - lightning + solar wind + a sunward region - a geocorona - minerals high in magnesium - solar X-rays - diffuse X-ray background - low-oxygen conditions
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with Jupiter? + lightning + aurora - a geocorona - minerals high in magnesium - solar X-rays - diffuse X-ray background + a sunward region - low-oxygen conditions
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with Saturn? + X-radiation concentrated near equator + reflection of solar X-rays - aurora + stronger than expected reflected solar X-rays - X-rays from rings - diffuse X-ray background + soft X-ray emission + fluorescence of solar X-rays
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with Venus? - scattering of solar X-rays - reflection of solar X-rays + fluorescence of solar X-rays + lightning - X-rays from rings - diffuse X-ray background + soft X-ray emission
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with Mars? - scattering of solar X-rays - reflection of solar X-rays + fluorescence of solar X-rays + lightning - X-rays from rings + collisions with solar wind + soft X-ray emission
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with the Moon? + scattering of solar X-rays + reflection of solar X-rays + fluorescence of solar X-rays - lightning - X-rays from rings + collisions with solar wind + soft X-ray emission
 * type="[]"}

{Which of the following are X-ray astronomy phenomena that may be associated with the Sun? + coronal cloud + hot regions of 8–20 x 106 K - fluorescence of Jovian X-rays - lightning - X-rays from rings - collisions with the Jovian wind + soft X-ray emission + hard X-ray emission
 * type="[]"}

{A method used to count the number of X-rays of a specific wavelength diffracted by a crystal? { wavelength dispersive X-ray spectroscopy|WDS (i) }
 * type="{}"}

{Many elements emit or fluoresce specific wavelengths of X-rays which in turn allow their? { identification (i) }
 * type="{}"}

{The incident beam may excite an electron in an inner shell, ejecting it from the shell while creating an? { electron hole (i) }
 * type="{}"}

{The number and energy of the X-rays emitted from a specimen can be measured by an? { energy-dispersive spectrometer|EDS|energy-dispersive X-ray spectrometer (i) }
 * type="{}"}

{A device that narrows a beam of particles or waves is a? { collimator (i) }
 * type="{}"}

{Complete the text: To "narrow" can mean to { cause (i) } the spatial { cross section (i) } of the beam to become { smaller (i) } limit.
 * type="{}"}

{Complete the text: The three key parameters of a { periodic (i) } waveform are its { amplitude|volume (i) }, { phase|timing (i) } and its { frequency|pitch (i) }.
 * type="{}"}

{Complete the text: With the modulation collimator, the amplitude ( { intensity (i) } ) of the incoming { X-rays (i) } is reduced by the presence of { two or more (i) } diffraction gratings of { parallel wires (i) } that block or greatly reduce that portion of the { signal (i) } incident upon the wires.
 * type="{}"}

{Complete the text: The multigrid collimator has the additional { grid (i) } inserted at a specified { intermediate (i) } position between the two grids, { aligned (i) } approximately { parallel (i) } to them, and { positioned (i) } and rotated so that each third { wire (i) } lies in a plane defined by a wire in the outer grid and a wire in the { inner (i) } grid.
 * type="{}"}

{Complete the text: The { collimating (i) } effects of the grid { enclosure (i) } or external metal { slats (i) } determine the envelope for the { triangular (i) } transmission peaks.
 * type="{}"}

{True or False, Wolter Type I X-ray optics uses three reflections to focus the incoming X-rays. - TRUE + FALSE
 * type=""}

{True or False, Wolter Type II X-ray optics uses two reflections to focus the incoming X-rays. + TRUE - FALSE
 * type=""}

{True or False, Wolter Type III X-ray optics uses one reflection to focus the incoming X-rays. - TRUE + FALSE
 * type=""}

{Which of the following is not a characteristic of X-ray optics? - grazing incidence mirrors - tungsten-silicon multilayer coatings - nested mirrors - an angular resolution + X-ray lens
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with the Crab Nebula? - a core which emits neutrinos + low-energy X-rays detected by the Chandra X-ray Observatory - 26Al - undetectable with balloon-borne detectors + hard X-rays + steady enough emission to be used as a standard for X-ray emission - observed with X-rays in 1731 + Taurus X-1
 * type="[]"}

{An Aerobee 150 sounding rocket flight on April 25, 1965, discovered how many candidate X-ray sources? { seven (i) }
 * type="{}"}

{Complete the text: The interstellar medium is the gas and { cosmic (i) } dust that pervade { interstellar (i) } space and is the matter that exists between the { stars|star systems (i) } within a { galaxy (i) }. It blends smoothly into the surrounding { intergalactic (i) } medium.
 * type="{}"}

{True or False, The energy that occupies the same volume as the interstellar medium in the form of electromagnetic radiation is the interstellar radiation field. + TRUE - FALSE
 * type=""}

{True or False, The hot ionized medium (HIM) consists of a coronal cloud which emits X-rays. + TRUE - FALSE
 * type=""}

{True or False, The first extragalactic X-ray source is the radio galaxy Messier 88. - TRUE + FALSE
 * type=""}

{Complete the text: An astronomical X-ray source may have one or more { positional|position (i) } locations, plus associated { error (i) } circles or { boxes (i) }, from which { incoming (i) } X-radiation has been { detected|detectable (i) }.
 * type="{}"}

{Complete the text: An astronomical X-ray source catalog is a list or { table|tabulation (i) } of astronomical { objects|sources|entities (i) } that are X-ray { sources (i) }, typically grouped together because they share a common { type (i) }, morphology, { origin (i) }, means of detection, or method of { discovery (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: sources - A 339 - B satellite - C earlier designation - D actual observation dates - E 4U - F The catalog contains how many? { B (i) } Prefix for sources detected during the final observation period { F (i) }. The fourth is a catalog of X-ray { A (i) }. Uhuru was a { C (i) }. The catalog does not necessarily contain the { D (i) }. It does not contain { E (i) }.
 * type="{}"}

{True or False, The 35 astronomical X-ray sources detected by sounding rocket in 1967 was launched by the X-ray astronomy group at NRL. + TRUE - FALSE
 * type=""}

{Which of the following is not a characteristic of SFXTs? - short outbursts + well fitted with a thermal synchrotron spectrum - OB supergiants - X-ray binaries - a growing number of transients
 * type=""}

{True or False, To reflect at the 79 keV level, glass layers are multi-coated with W/SiC. - TRUE + FALSE
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with the Ulysses spacecraft? + hard X-ray detectors + CsI(Tl) scintillators + soft X-ray detectors - windowless soft X-ray detectors + detected soft X-ray emission inside two solar radii over the poles + higher energy X-rays detected with a maximum at about five solar radii over the poles - observed X-rays in the 1980s - discovered Circinus X-1
 * type="[]"}

{Which of the following X-ray phenomena is not a characteristic of the Helios satellites? + heliocentric orbit - short-lived (0.5 h) soft X-ray events - longer-lived X-ray events (3 h on average) - any steady X-ray source - XREs
 * type=""}

{True or False, The NuSTAR observatory has a 10.14 m instrument focal length for its Wolter I telescopes. + TRUE - FALSE
 * type=""}

{Which of the following are X-radiation astronomy phenomena associated with the NuSTAR spacecraft? + hard X-ray detectors + CdZnTe pixel detectors + CsI anti-coincidence shield - windowless < 3 keV soft X-ray detectors + 1.5" strong source positioning + 2 µs X-ray temporal resolution + 900 eV at 68 keV spectral resolution + FOV at 68 keV of 6'
 * type="[]"}

{Complete the text: Match up the item letter with each of the possibilities below: Sun - A Mercury - B Venus - C Earth - D Comets - E Mars - F Jupiter - G Saturn - H Auroral currents on the order of 106 Amps { G (i) } Fluorescent radiation from oxygen at ~130 km above the surface { C (i) }. Faint halo of X-rays extending out some 7,000 km { F (i) }. Solar wind lighting up with X-rays { E (i) }. Bright X-ray arcs at low energy { D (i) }. Major source of hard X-rays { A (i) }. X-ray emission concentrated near the equator { H (i) }. Low surface iron content in minerals { B (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: synchrotron X-rays - A power law - B inverse Compton - C thermal Bremsstrahlung - D black body - E cyclotron - F Supergiant Fast X-ray Transients { D (i) } Galactic diffuse emission { B (i) }. Crab nebula { A (i) }. continuum { C|D|E|A (i) }. accretion disk { E (i) }. strongly magnetized neutron stars { F (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: X-ray burster - A gamma-ray burster - B X-ray pulsar - C SFXT - D soft X-ray transient - E diffuse X-ray background - F power law afterglow { B (i) } magnetized neutron star { C (i) }. absorbed by neutral hydrogen { F (i) }. Aquila X-1 { E (i) }. Factor of 10 or greater luminosity increase { A (i) }. thermal bremsstrahlung { D (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Moon - A Eros - B Io - C Ganymede - D Europa - E Titan - F X-ray producing electric arc, current spots { C (i) } reflecting solar X-rays { A (i) }. soft X-ray emission { C|E (i) }. possible soft X-ray emission { D (i) }. synchrotron X-ray diffraction of methane hydrate up to 10GPa { F (i) }. ordinary chondrite composition { B (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Skylark - A V-2 - B Nike-Asp - C Aerobee 150 - D Black Brant XII - E Vertikal - F Terrier Sandhawk - G Wallops Flight Facility { E (i) } Woomera, Australia { A (i) }. Natal, Brazil { D (i) }. Kapustin Yar { F (i) }. White Sands Missile Range { B|D (i) }. Point Defiance { C (i) }. Barking Sands { G (i) }. White Sands Proving Grounds { B (i) }.
 * type="{}"}

{True or False, The NRL and NASA established another rocket launching facility outside Natal, Brazil to detect X-ray sources in the southern hemisphere. + TRUE - FALSE
 * type=""}

{Complete the text: Match up the item letter with each of the possibilities below: Hydrogen - H, or D Helium - He Lithium - Li Beryllium - Be Boron - B Carbon - C Nitrogen - N Oxygen - O Fluorine - F Neon - Ne consumed in chromosphere fusion to produce lithium and neutrinos { Be (i) }. isotope fusion in the chromosphere producing neutrinos { He (i) } fusion in the chromosphere producing the most neutrinos { H|D (i) }. a factor of ~200 below meteorite abundance in the Sun's photosphere { Li (i) }. detected with X-rays on the Moon { O (i) }. an organic form detected in Allan Hills 84001 probably from Mars { C (i) }. detected marginally on Venus with Chandra { N (i) }. found in the X-ray spectra of comets { Ne (i) }. consumed to produce beryllium and neutrinos { B (i) }. a surface impurity on meteorites { F (i) }.
 * type="{}"}

{Which of the following are associated with X-radiation? + spans three decades in wavelength + spans three decades in frequency + spans three decades in energy + emitted by 26Al + coronal clouds + 60 keV electromagnetic radiation + 90 eV electromagnetic radiation - visually dark source
 * type="[]"}

{True or False, The cosmic X-ray background has higher intensity than the cosmic radio background. + TRUE - FALSE
 * type=""}

{True or False, Ranger 2 carried instruments that detected the X-ray background. - TRUE + FALSE
 * type=""}

{True or False, Super soft X-ray sources have been detected in the Magellanic clouds. + TRUE - FALSE
 * type=""}

{True or False, To fall into the class of intermediate X-ray binaries, the X-ray source must be intermediate in luminosity. - TRUE + FALSE
 * type=""}

{True or False, Inverse Compton scattering allows low energy electromagnetic radiation to become high energy electromagnetic radiation. + TRUE - FALSE
 * type=""}

{Complete the text: While exceptions may occur, match up the star class letter with each of the X-ray possibilities below: star class - O star class - B star class - A star class - F star class - G star class - K star class - M LX >> Lv { M (i) }. constant X-ray luminosity across the class { B (i) } independent of visual luminosity { F (i) }. LX ~ 10-3Lbol { G (i) }. abrupt onset of X-ray emission across the class { A (i) }. LX ~ 10-7Lbol { O (i) }. LX << 10-3Lbol { K (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Scorpius X-1 - A Serpens X-1 - B Circinus X-1 - C Virgo X-1 - D Taurus X-1 - E Cygnus X-1 - F Cepheus X-1 - G Sagittarius X-1 - H Crab Nebula { E (i) } Messier 87 { D (i) }. 2U 1744-26 { H (i) }. Tychos's Nova SN 1572 { G (i) }. Carina X-1 misprint { C (i) }. the first X-ray source widely accepted to be a black hole candidate { F (i) }. discovered in 1962 by a team under Riccardo Giacconi { A (i) }. not Caput { B (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Chemistry - A Geography - B History - C Mathematics - D Physics - E Science - F Technology - G Geology - H solar eclipses { B (i) } a spatial frequency of occurrence or extent { E (i) }. radio observations revealed a radio corona around the Sun { C (i) }. elemental abundances { A (i) }. microcalorimeter arrays { G (i) }. The Ariel V /3 A/ catalogue of X-ray sources. II - Sources at high galactic latitude |b| > 10° { F (i) }. Carancas meteorite { H (i) }. a thermal bremsstrahlung source may fit { D (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Meteors - A Cosmic rays - B Neutrons - C Protons - D Electrons - E Positrons - F Gamma rays - G Superluminals - H X-ray jets { C (i) } the index of refraction is often greater than 1 just below a resonance frequency { H (i) }. iron, nickel, cobalt, and traces of iridium { A (i) }. Sagittarius X-1 { G (i) }. escape from a typical hard low-mass X-ray binary { F (i) }. collisions with argon atoms { B (i) }. X-rays are emitted as they slow down { E (i) }. Henry Moseley using X-ray spectra { D (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Balloons - A Sounding rockets - B Aircraft assisted launches - C Orbital rocketry - D Shuttle payload - E Heliocentric rocketry - F Exploratory rocketry - G Lunar rover - H Ranger 5 { F (i) } microcalorimeter arrays { B (i) }. MeV Auroral X-ray Imaging and Spectroscopy { A (i) }. Lunokhod 2 { H (i) }. ALEXIS { C (i) }. Ulysses { G (i) }. Broad Band X-Ray Telescope { E (i) }. Solar Heliospheric Observatory { D (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the possibilities below: Optical bench - A Focal length - B CCD - C Coded aperture - D Grazing incidence - E Modulator - F Collimator - G Normal incidence - H a device for the movement of electrical charge { C (i) } gold mirrors { E (i) }. narrows a beam { G (i) }. a measure of how strongly a system converges or diverges { B (i) }. reflective multilayer optics { H (i) }. varying amplitude, phase, or frequency { F (i) }. a flat grille { D (i) }. a platform used to support systems { A (i) }.
 * type="{}"}

{Complete the text: Match up the item letter with each of the X-ray angular resolution possibilities below: Rossi X-ray Timing Explorer - A XMM-Newton - B Chandra X-ray Observatory - C Swift - D Astro-rivelatore Gamma ad Imagini Leggero (AGILE) - E Solar Heliospheric Observatory - F Suzaku - G Koronas-Foton - H 2" { D (i) } 3" { H (i) }. ~2' { G (i) }. 1" { B|F (i) }. 5.9' { E (i) }. 7' { A (i) }. 1" { B|F (i) }. 0.5" { C (i) }.
 * type="{}"}

Hypotheses

 * 1) Gamma-ray emitters should be emitting X-rays as well.