A) Rock formations B) Gas and dust C) Liquid water D) Plasma
A) Gamma rays B) Radio waves C) Visible light D) X-rays
A) Radiative torque alignment B) Microwave heating C) Ionization imbalance D) Heat conduction
A) Reflection nebulae B) Molecular clouds C) Supernova remnants D) H II regions
A) Hydrogen B) Helium C) Oxygen D) Carbon
A) Silicates B) Diamonds C) Platinum D) Gold
A) Carbon dioxide (CO2) B) Polycyclic aromatic hydrocarbons (PAHs) C) Methane (CH4) D) Carbon monoxide (CO)
A) Blue B) Green C) Red D) Yellow
A) Supernova remnant B) Reflection nebula C) Dark nebula D) H II region
A) 10 quadrillion (1016) molecules/m3 B) 100 ions/m3 C) 1 billion (109) molecules/m3 D) 1 trillion (1012) molecules/m3
A) Cold dense phase B) Coronal gas C) Photodissociation region D) Warm ionized medium
A) 1% B) 5% C) 10% D) 50%
A) OB stars B) Neutron stars C) White dwarfs D) Red giants
A) ~ 104 K B) O(105 K) C) ~ 106 K D) < 300 K
A) ~ 1016 molecules/m3 B) ~ 1012 molecules/m3 C) ~ 100 ions/m3 D) ~ 1025 molecules/m3
A) Photodissociation region B) Very hot gas (T ~ 106 K) C) Warm intercloud phase D) Cold dense phase
A) Thermal pressure is more important than magnetic fields. B) The phases are roughly in pressure balance over most of the Galactic disk. C) All phases have equal density. D) Pressure varies significantly across different regions.
A) Francis Bacon B) William Huggins C) Edward Barnard D) René Descartes
A) Forbidden lines of O III B) 21-cm line of H I C) Ly-α photon from hydrogen D) Spectral lines from CO
A) Stellar nucleosynthesis during stellar evolution. B) Interstellar dust C) Cosmic rays D) Primordial nucleosynthesis
A) They reduce the number of hydrogen atoms. B) They create cold neutral medium. C) They decrease the density of the ISM. D) They convert surrounding gas into the warm ionized phase, increasing temperature.
A) Bremsstrahlung radiation B) Synchrotron radiation C) Photon emission from de-excitation D) Inverse Compton scattering
A) Far infrared quasi-blackbody emission B) Millimetre wavelength lines C) Dipole radiation D) 21-cm line emission
A) CO (carbon monoxide) B) N II C) O III D) H2 (molecular hydrogen)
A) Bremsstrahlung cooling B) Inverse Compton scattering C) Synchrotron radiation D) Collision with atomic nuclei
A) It compresses all ISM into a thin disk. B) It influences their dynamics and structure. C) It has no effect on the ISM. D) It prevents star formation in spiral arms.
A) It remains unchanged from the rest of the galaxy. B) It becomes entirely in the coronal phase. C) It is profoundly modified by the central supermassive black hole. D) It only contains cold gas.
A) Far infrared quasi-blackbody emission B) Millimetre wavelength lines C) 21-cm line emission D) Synchrotron radiation
A) Quasi-blackbody emission B) Bremsstrahlung radiation C) Inverse Compton scattering D) Synchrotron radiation
A) 2025 B) 2030 C) 2040 D) 2020
A) Scattering B) Emission lines C) Absorption lines D) Reddening
A) Simple hydrocarbons. B) Buckminsterfullerene (C60) or 'buckyballs'. C) Only hydrogen and helium molecules. D) Carbon monoxide.
A) Mary Lea Heger B) Slipher C) Victor Hess D) Edward Barnard
A) Telescope lens B) Photography C) Refraction D) Spectroscopy
A) Synchrotron radiation B) Bremsstrahlung radiation C) Inverse Compton scattering D) Fine structure cooling
A) They cool down the ionized gas. B) They increase the density of molecular clouds. C) They contribute to the heating of the warm neutral medium. D) They reduce the number of photons with energy below the Lyman limit.
A) Brackett-alpha transition B) Lyman-alpha transition C) Paschen-alpha transition D) Balmer-alpha transition
A) Dipole radiation from spinning nanometre-sized grains B) Far infrared quasi-blackbody emission C) Synchrotron radiation D) Bremsstrahlung radiation
A) Bremsstrahlung radiation B) Synchrotron radiation C) Infrared emission D) Gamma-ray photons
A) 500 parsecs B) 30,000 parsecs C) 10,000 parsecs D) 100 parsecs (300 light years)
A) 50 km/s B) 1000 km/s C) 200 km/s D) 500 km/s |