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