A) A theoretical error in general relativity B) A basic unit of cosmological structure C) A byproduct of black hole radiation D) A type of visible galaxy
A) It is unaffected by the expansion of space B) It expands faster than the universe C) It has decoupled from cosmic expansion D) It is actively being created by cosmic expansion
A) Gaseous clouds within the galactic disc B) Regions of space devoid of any matter C) Smaller galaxies that orbit the Milky Way D) Virialized clumps of dark matter bound by gravity
A) They are created by galaxy collisions B) They may contain galaxies C) They only exist outside of galaxies D) They replace galaxies entirely
A) Only to the edge of the visible galactic disc B) Only to the center of the galactic bulge C) Well beyond the edge of the visible galaxy D) It is confined within the visible stars
A) Yes, using optical telescopes B) Yes, using particle detectors in space C) No D) Yes, using infrared scanners
A) Through effects on star and gas motion and gravitational lensing B) By measuring the heat emitted by the halo C) By counting the number of galaxies in a cluster D) Through direct visual observation
A) Cold dark matter (CDM) B) Dark energy plasma C) Galactic magnetic resonance D) Solar wind particles
A) The absence of mass at large distances B) The galaxy is shrinking toward the center C) The presence of dark matter D) The rotation slows down significantly at the edges
A) It would remain constant B) It would cease entirely C) It would decrease D) It would increase
A) X-ray bursts from the galactic core B) 21 cm Hydrogen line C) Cosmic microwave background radiation D) Ultraviolet light emissions
A) It flattens out B) It increases exponentially C) It drops off sharply D) It fluctuates randomly
A) Albert Einstein B) Ken Freeman C) Edwin Hubble D) Isaac Newton
A) The Triangulum and the Magellanic Clouds B) The Milky Way and Andromeda C) Centaurus A and Sombrero D) NGC 300 and M33
A) General relativity is incomplete B) Intergalactic dust interference C) The presence of black holes at every star system D) Excessive solar radiation
A) It was moving too slowly to form structures. B) It was interacting too strongly with dark energy. C) Its temperature was too high. D) It lacked sufficient mass.
A) Spherical collapse B) Radiative pressure modeling C) Linear expansion D) Baryonic oscillation
A) Ellipsoidal B) Perfectly spherical C) Irregular filamentary D) Flat disk
A) The core radius is not defined for large distances. B) It does not provide a good fit to rotation curve data. C) The central density is infinite at the core radius. D) The enclosed mass fails to converge as the radius tends to infinity.
A) Pseudo-isothermal profile B) Einasto profile C) NFW profile D) Spherical-collapse profile
A) Characteristic density B) Scale radius C) Finite central density D) Critical density
A) Critical density B) Central density C) Scale radius D) Characteristic density
A) The scale radius is always zero. B) The critical density of the universe is too low. C) Mergers associated with hierarchical formation. D) The mass converges too quickly.
A) The scale radius rs. B) The radius where the density is zero. C) The core radius rc. D) An overdensity 200 times greater than the critical density.
A) Only at the center. B) Yes C) No, it diverges to infinity. D) Only at the scale radius.
A) Perfectly spherical B) Flat disks C) Aspherical D) Cubical
A) Strong tidal forces B) Dark energy repulsion C) Electromagnetic radiation D) Surface friction
A) Exponential distribution B) Normal distribution C) Uniform distribution D) Log-normal distribution
A) 0.035 B) 0.001 C) 0.050 D) 0.100
A) About 75% B) About 50% C) About 95% D) About 25%
A) 6×1011 M☉ B) 1×109 M☉ C) 3×1012 M☉ D) 9×1010 M☉
A) 0.00088 M☉ pc-3 B) 0.0088 M☉ pc-3 C) 0.88 M☉ pc-3 D) 0.088 M☉ pc-3 |